Biocontrol Agents Currently Unavailable for Redistribution

Below is a list of 42 biological control agents that are still being tested for suitability in BC, and are currently NOT AVAILABLE for redistribution. They are described here for informative purposes only.

Jump to any of the following agents and their target plants:

	Aphis chloris (Koch)
Attacks:	St. John's wort
Agent Type:	Sap sucking aphid
Origin:	The A. chloris released in BC derive from populations collected in Austria, Germany, Hungary and Switzerland.
Adult:	Aphis chloris typically appear similar to common aphids, lime green (olive green in cooler climates), and measure 1-2mm. Self-fertile females hatch from overwintered eggs in June and go on to produce live young. It takes the live young six days at 25°C or 10-11 days at 17-18°C to reach the reproductive adult stage. Multiple live young births continue until cool temperatures in the early fall. In warm conditions, self-fertile females continue to be produced. In northern climates the onset of cool, short days during September initiates the production of males and egg producing females. With these cooler temperatures the females begin to lay eggs, often doing so without mating. Each female will produce an average of only four eggs, depositing them onto basal winter foliage. From summer until fall, winged females will disperse in crowded conditions to develop new colonies. Adults and nymphs congregate on stems, root collars, leaf axils, flowers and leaves.
Egg:	Eggs initially are yellow, turning shiny black over time.
Larva/Pupa:	Aphids do not have a larvae stage, they develop from egg, to nymph to adult. Nymphs are immature versions of the adult.
Overwintering:	Eggs laid in September and October overwinter and hatch the following season.
Location & Efficacy:	Adult and nymph stages feed on plant fluids, avoiding the photosensitizing toxins by feeding on phloem sap. Stems and leaves are attacked and in high populations can cause plants to wither and die. Often they can be located on stem bases, near the basal leaves and root crown. In field studies, healthy potted plants were killed in one month when attacked by A. chloris.
Habitat:	A. chloris's preferred Canadian climate is similar to maritime, where summers are humid-and temperatures are cool, 20-25°C. It does not do well in hot, dry locations where plants wither and burn from heat. Sufficient cold winter temperatures are required for egg development. Climate variations determine the life cycle pattern. In Europe, Aphis chloris is common in a wide geographic range. In BC, releases have been made in the Bunchgrass, Coastal western hemlock, Interior cedar hemlock, Interior Douglas-fir and Ponderosa pine biogeoclimatic zones. There is a recorded site in the Engelmann spruce-subalpine fir zone, but this still requires confirmation. Establishment has been found in the Bunchgrass, Interior cedar hemlock and Interior Douglas-fir and Ponderosa pine zones. It is still too early to determine the status of the recent release made in the Coastal western hemlock zone.
History:	In 1979 A. chloris was first released into the east Kootenays. Infrequent field releases were made between 1979 and 1997 from populations reared in Saskatchewan and Alberta. These were released within the BC southern interior. In 2008 the first field collection was made and released into the Fraser Valley.
Field Results:	Establishment has been found at most release locations at this time. In 2005 aphids were located at several locations by late-spring. The next year at these same sites, no aphids could be located by mid-August. It is not known if the prolonged heat-wave was the reason for their absence. In 2008 the first field collection was taken from the Southern Interior Forest Region and moved to the Coastal Forest Region. It is still too early to determine if the recent attempt to move the aphids from the dry interior habitat to a moist site in the Fraser Valley was successful.
Notes:	A. chloris is the only common aphid found on St. John's wort. In eastern Canadian maritime habitat, 60km dispersal was recorded in eight years. Rapid dispersal can result in low density populations.

	Aphthona flava (Guill.)
Attacks:	Leafy spurge, Cypress spurge
Agent Type:	Root feeding flea beetle
Origin:	A. flava released in BC originated in Hungary and Greece. The flea beetles were released in 1982 and 1983 near Cardston, Alberta and reared to collectable levels before being shipped to BC.
Adult:	Adults are orange-coppery coloured and 2-4mm long. Of all the biocontrol Aphthona species released in BC, Aphthona flava is the largest, with females slightly larger than males. The flea beetles emerge from mid-June through mid-August, and persist into the fall if the weather is warm. One week after emerging, females begin to oviposit the eggs in clusters of 20 to 30 underground near spurge stems. Egg laying is done every 3-4 days, with females averaging 224 each over the 3.5 month period. Oviposition is intense for the first two months, tapering off thereafter. Adults are uniquely sensitive to air movement and shadows, which enables them to better cope within grazed pastures where they readily jump to avoid being consumed by livestock. Adults will move into light or filtered shaded areas.
Egg:	The pale yellow, 0.7 x 0.4mm eggs hatch in 20 days.
Larva/Pupa:	Larvae are white and slender with brown heads and often in a comma-like position. The youngest larvae feed on latex-free fibrous roots. The later instars feed on larger young roots. The larvae stage requires 168 days over 11°C. Once mature, they are hardy to -6°C. Active feeding lasts about 105 days before they construct and move into a soil particle chamber. Larvae that have not completed the required feeding before winter or fail to experience at least 4-months of 10°C or less will not mature. Mature larvae pupate the following spring within the chamber. Pupation begins after 28-57 days of warm spring weather. It will spend 20-25 days in pupae form before emerging.
Overwintering:	Larvae overwinter within the soil in soil particle chambers.
Location & Efficacy:	Larvae feed on root hairs, young roots and parts of the main root, reducing the plant's ability to absorb moisture and accumulate nutrients. Adult foliar feeding is quite impressive as they consume small leaves and buds. Each Aphthona species group feeds in a specific manner; brown coloured flea-beetles, including A. flava, feed on the leaf margins. Foliar feeding can impede the plant's photosynthesis and can cause nutrient starvation.
Habitat:	A. flava require warm, sunny locations where soils are sandy or coarse gravel. They prefer sites with a high water table, so gullies and river valley bottoms are suitable. The flea beetles are often found on sites where widely spaced spurge grows near cottonwood trees. Of all the Aphthona species, they require more heat units for development. Short surrounding vegetation (grazed areas) can increase the heat at what would otherwise be non-suitable locations. A climate with a 4-month period of temperatures of 10°C or less is required for complete development. Like all Aphthona species, they too compete poorly where ant populations are present. In BC, A. flava has established in the Bunchgrass, Interior Douglas-fir and Ponderosa pine biogeoclimatic zones. A release made into the Montane spruce zone has not established and is believed to be outside of A. flava's desired habitat. All the successfully established sites are hot locations with cottonwoods and/or water sources nearby and have an almost equal ratio of open canopy and lightly filtered canopy. One consistent feature at all successful locations is where the host plants are surrounded by a mix of other plants of similar height to the spurge. At one non-established Bunchgrass site, it is believed that the plant density is too high and therefore not desirable. The flea-beetles appear to favour widely spaced plants mixed with other vegetation.
History:	The first A. flava release was made northwest of Clinton in 1990. No recovery has been found at this location. Subsequent treatments from the Alberta population were made between 1992 and 1995 in the southern interior and have successfully established. In 1999 the first field collection was made from a small site near Kamloops and continues to provide populations for redistribution.
Field Results:	A. flava sites easily established at many of the sites revisited. Further work has been limited because many of the release sites have become developed and are no longer accessable. In the past, adults were located the first week of August, but in recent years they have been observed earlier, with collections starting in mid-July. In 1998 a site near Kamloops had no plants remaining and by 2005 the plants had re-established and so had the A. flava population. Since then, the site has remained intact and is used as a collection source for further redistribution. Dispersal sampling done in 2008 indicates that A. flava may not disperse as freely as other Aphthona species.
Notes:	A. flava's ability to drop and leap away when threatened enables the adult to survive in a grazed environment.

	Aphthona lacertosa (Rosh.)
Attacks:	Leafy spurge, Cypress spurge
Agent Type:	Root feeding flea-beetle
Origin:	The A. lacertosa populations released in BC came from North Dakota, reared from Hungarian stock. They arrived in a mixed population with up to 80% A. czwalinae.
Adult:	Aphthona lacertosa bodies are black and 2.5-3.4mm long and are equally tapered throughout. The upper part of their rear legs are brown, making it only slightly different than A. czwalinae and difficult to tell them apart. Emerging adults appear in early-June, usually 10 days before A. czwalinae, and continue into mid-August. Females lay eggs in small batches at the base of leafy spurge stems. Each female lays 200-300 eggs during their six to eight week oviposition period. As with all flea-beetles, it too is capable of jumping great distances and does so readily. It is considered the most active of all the Aphthona species. Adults adjust to temperature by seeking sun on cold days and moving to shade or onto lower plant leaves during hot days. Some populations have short wings, while others do not; there is no explanation for this. Adults can live up to two months.
Egg:	Eggs are pale yellow and measure 0.7 x 0.4mm.
Larva/Pupa:	Larvae are white and slender with brown heads and often in a comma-like position. The first instar begins to mine latex-free fibrous roots and later instars move onto the outside layer of older roots. Once the larvae have finished feeding, they leave the roots and move into the soil to prepare to pupal cell. Mature larvae require a 4-month cold period to initiate further development. Late hatchings that encounter the cold weather before they feed sufficiently will survive the winter, but will not go on to reproduce. Pupation occurs the following year and is completed by the end of spring or early summer.
Overwintering:	Mature larvae overwinter in a pupal cell in the soil.
Location & Efficacy:	Larvae feed on fibrous roots before moving onto the mature roots. The larvae appear to concentrate on specific plants, resulting in plant death and reducing the plant density as opposed to retarding the plant vigour. High concentrations can cause a 'hole in the spurge', where the plants become noticeably reduced. Adults feed on leaves, terminals, margins and shoots. In dense populations, adult feeding is quite impressive and can defoliate the plants significantly, reducing the plant's ability to photosynthesize and further reducing the plant's nutrients required for healthy growth and reproduction.
Habitat:	Aphthona lacertosa have shown a preference for open or lightly shaded sites with clay loam soils, establishing on heavier soils than A. nigriscutis and A. cyparissiae. They have a wide adaptation to climatic conditions, accepting mesic-dry to moist areas, avoiding very dry sites. Similarly to A. czwalinae, they prefer sites with well-developed mixed vegetation surrounding shorter host plants. They are capable of filling a niche in areas the other species do not. A climate with a 4-month period of temperatures of 10°C or less is required for complete development. Like all Aphthona species, they compete poorly where ant populations are present. In BC, limited releases have been made into the Bunchgrass, Interior Douglas-fir and Ponderosa pine biogeoclimatic zones. They have established in the Interior Douglas-fir and Ponderosa pine zones. It is believed that the plants at the site in the Bunchgrass zone occur at a density that is less desired by the flea-beetles.
History:	A. lacertosa was first introduced to BC in 1995 in a mixed population with A. czwalinae. They were released at two locations, one in the north-Okanagan and the other in the south-Cariboo. Only a few releases were made from imported populations between 1995 and 1997. In 2000, the first small field collection was made from what has become the only collection site in BC.
Field Results:	The narrow adult emergence window requires frequent site visits to avoid missing the agents' peak period. In the southern interior this stage appears to last only one month. In 2000 the first field collection was made from a site in the north-Okanagan. Since this time, small collections have continued from here and are used to supplement a previous release site, and to establish a new site near Kamloops. The earliest adult sighting have been in late-May at the Okanagan site. Despite the possibility that early emerging adults have high mortality rates, a recent collection and treatment made in May 2005 resulted in survival over its first year. No efforts have been made to determine which species is dominant at any of the established locations.
Notes:	There can be high mortality in the larvae stage caused by the parasitic protozoan Nosema spp. All Aphthona species have narrow habitat requirements and will not attack spurge growing in unsuitable microhabitats. It may be desirable to combine the efforts of A. nigriscutis and A. lacertosa over rolling sites which may have pockets of habitat requirements for both.

	Aplocera plagiata (L.)
Attacks:	St. John's wort
Agent Type:	Foliar feeding moth	Previously Known As:	Anaitis plagiata
Origin:	The A. plagiata populations released in BC originated in France, Germany and Switzerland.
Adult:	The moths are overall light grey coloured and referred to as 'treble-bar moths'. Their wingspan is between 2.7 and 4.0cm. When at rest, the wings are held in a triangular shape. The first generation adults emerge in May and June in fewer numbers than the summer generation. The second generation adults appear when the host plants are flowering, usually from August to September. Mating and oviposition begins shortly after the adults emerge. Females lay up to 300 eggs onto upper and lower leaf surfaces or on stems. Adults make frequent erratic flight patterns when disturbed and land a short distance away before taking flight again. They are strong fliers which enables them to easily seek scattered patches.
Egg:	The eggs are oval-shaped and pearl white. They will incubate for 5-7 days.
Larva/Pupa:	The 'inch worm-like' larvae develop through various stages and change from their initial light brown/tan and green colour to darker brown, with deep shading along their upper back and dark stripes along their body. When they are fully mature the larvae will measure 2.2cm long. When disturbed they will mimic dead twigs. The first generation appear in early-August. Newly emerged larvae feed on the plant leaves, avoiding toxic leaf glands until they are old enough to have developed immunity. Mature larvae burrow into the soil to pupate which takes 12-17 days to complete. Pupae are slender and light greenish-golden brown. The larvae can withstand high and low temperatures, but harsh winters, high elevations, and northern locations may affect the overwintering generation if they do not develop sufficiently before winter. Moist soils can cause fungal infections.
Overwintering:	Immature larvae overwinter in the soil and resume feeding the following spring.
Location & Efficacy:	The spring generation feeds on leaves and is capable of substantially defoliating plants. The summer generation feeds on flowers. Foliar feeding is usually observed before the larvae are located.
Habitat:	Aplocera plagiata is commonly associated with well drained soils in warm continental climate areas. Dry sites with rocky or sand-based soils and some limestone are suitable. Wet climates or moist soils are unsuitable. In Europe, A. plagiata exists to the northern limits of St. John's wort, but does not occur in warm dry sites. In Bc, A. plagiata releases have been made and found established in the Coastal western hemlock, Interior cedar hemlock and Interior Douglas-fir biogeoclimatic zones. Establishment has not been confirmed in Sub-boreal spruce near Quesnel. It is too soon to determine the status of the recent attempt to move populations from the BC southern interior to Vancouver Island.
History:	A. plagiata was brought to BC in 1967. Two field treatments were made in the west-Kootenays and establishment was later confirmed. Releases continued from 1967 to 1987. The first BC field collection was made in 1992 from a release site near Grand Forks. No further field collections occurred until 2008.
Field Results:	Dispersal sampling done in 2008 indicate that the moth is freely distributing itself throughout the southern interior. Larvae can easily be located during rainy periods, which indicates they may tolerate wet conditions. Two adult specimens, collected in May (2005), laid 35 eggs and all hatched one week later. The larvae fed for 15 days in captivity, and were then transferred to a field site.
Notes:	This is the only inch worm found on St. John's wort.

	Bruchidius villosus (F.)
Attacks:	Scotch broom, French broom
Agent Type:	Seed feeding beetle (weevil)
Origin:	B. vllosus is an adventive agent that is believed to have entered BC from the Pacific North West, where releases began in 1998 from populations collected in North Carolina. The weevils released in North Carolina originated in the United Kingdom.
Adult:	The black adult weevils are 2-4mm long, with parallel lines running the length of the wing covers. Overwintered, sexually immature adults emerge in March and April, and a new generation occurs in July and August. To reach sexual maturity, adults are required to feed on broom pollen. If adults emerge before broom is in flower, they first feed on gorse before moving back onto broom. Oviposition begins when young green pods begin to form. The females will lay eggs individually or in horizontal rows onto young green pods and cement them in place. Adults are active walkers and quickly take flight once pods open.
Egg:	Eggs are 0.3mm long, oval and pale green coloured. During incubation, the eggs change from the pale green to purple.
Larva/Pupa:	There are four larvae instars. The newly-hatched larvae move across the pod, often leaving a very fine blue trail before chewing into the pod cavity where they attack soft green seeds. After they have entered into the pod, their complete development occurs within a single seed inside a closed pod. Several larvae can develop in each pod, but each will occupy their own seed. After a short pupation phase the new adults chew through the seed coat, but remain inside the pod until it splits open.
Overwintering:	Adults overwinter near the host plants seeking protection in plant litter or crevices.
Location & Efficacy:	Bruchicius villosus larvae feed on seeds. High populations can reduce seed production which decreases plant density and spread. Adults feed on pollen, foliage and stems.
Habitat:	The weevil has an extensive native European range and can be found in Austria, Denmark, Germany, Hungary, Italy, Switzerland, United Kingdom, France, Portugal and Spain. B. villosus is expected to survive in any area where the host plant establishes, but specific habitat requirements are currently being studied. In BC, adventive populations of B. villosus have been found dispersed within the Coastal Douglas-fir and Coastal cedar hemlock biogeoclimatic zones. Successful establishment has occurred from collections taken from these zones and released into the Interior cedar hemlock zone.
History:	B. villosus was first discovered on Vancouver Island in 2001. Recent investigation has found its dispersal within the Lower Mainland, in the Fraser Valley, on Vancouver Island and on some coastal islands. In 2006, adults were collected from Vancouver Island and the first field treatment was made in the central-Kootenays. A second collection was made from a Fraser Valley site, with both B. villosus and E. fuscirostre present, for release into the Kootenays. Establishment at both the 2006 and the 2007 sites was confirmed in 2008. In 2008 another population was collected and was released into a slightly more northern habitat near Upper Arrow Lake.
Field Results:	B. villosus have been found on plants adjacent to tidal flats and in salt spray locations, which indicates it may have a high tolerance for saline conditions. It is commonly found sharing inland host plants with Exapion fuscriostre, another adventive agent. Based on the 2007 collection calculations, B. villosus outnumbers E. fuscirostre. An estimated 2800 pods were collected and the ratio was 5680 B. villosus to 1400 E. fuscirostre, or 80/20% B. villosus to E. fuscirostre per pod.
Notes:	B. villosus is more active than E. fuscirostre. E. fuscirostre can be confused with B. villosus in the larvae and pupae stages. The size of the seed may influence the size of new adults. In test plots, larger seeds produced larger adults.

	Calophasia lunula (Hufn.)
Attacks:	Dalmatian toadflax, Yellow/Common toadflax
Agent Type:	Foliar feeding moth
Origin:	Canadian populations came from European stock. The first C. lunula releases were made in five provinces, including BC.
Adult:	Adult moths are light brown-grey with a wingspan of 27-30mm. The forewings have a white crescent mark and irregular white flecks while the rear wings are brownish-white. Calophasia lunula is a strong flier. Adults appear between May and August. Mating begins immediately, and egg laying starts 1-2 days later. Females lay 100 and 400 eggs each. Eggs are laid singly on leaf and flower surfaces and are usually laid after midnight. When temperatures are 27°C most will be laid within four days. Adults can be found at dusk feeding on toadflax flower nectar. Their life span is linked to temperature, usually surviving 10-25 days. At 21°C the egg to adult the cycle takes 58 days to complete.
Egg:	Eggs are strongly-ribbed, 0.8mm and conical shaped. During incubation the eggs change to reddish-brown. At 21°C, they hatch in seven days.
Larva/Pupa:	There are five instars and when temperatures are 21°C the larval stage lasts 27 days. Newly hatched larvae are grey-black and about 5mm long. Mature larvae are pearly-white to bluish-white with lateral rows of black spots, five yellow stripes and two broken black lines. The larvae are very distinct and grow to 4cm long. Moulting between instars depends on feeding conditions. A specific amount of food is required to reach a size to initiate the moult. During the entire larval stage, each will consume 38.6cm of stem foliage. The first two instars each last five days, preferring to feed in flowers and moulting at 5mm and again at 8mm. Feeding becomes more aggressive during the final three stages and encourages the larvae to disperse. The third instars last five days and moult at 12mm. The fourth instars last about seven days and moult at 19mm. The final instars require 12 days to complete but do not moult. They prepare for pupation by moving into the soil where they construct cocoons from chewed leaves, litter, or soil. Pupae measure 15mm x 4.5mm and become golden or reddish-brown. The earliest to complete pupation will go on and produce a second generation of adults that will appear in late-summer or early-fall. In some climates a third generation is possible, but usually they will overwinter as second generation pupae.
Overwintering:	Pupae overwinter within the soil in cocoons constructed from chewed leaves, plant litter and soil particles.
Location & Efficacy:	Larvae feed on flowers, floral buds and foliage. The young larvae can completely destroy flowers during the first two instar feedings. Older larvae feed on the new vegetative shoots, tender leaves, and flowers. When new foliage is not available, mature leaves will be consumed. In sufficient numbers the defoliation is quite impressive. The feeding depletes stored nutrients and overall vigour of the plant which impacts the plant during the next growing season. Flower and bud feeding decrease seed production.
Habitat:	Areas with warm summers are required for larvae development. Its preference for drought-stressed plants confirms the need for sites that remain warm during summer. Yellow toadflax sites near water may be favoured. Different strains of C. lunula may prefer either yellow or Dalmatian toadflax. The native distribution of C. lunula occurs in central Europe and central Asia into the Amur region of the Pacific. A remote population occurs in Scandinavia. It is absent from areas with high rainfall and cool summers. It occurs in areas where the temperature can be as low as -40oC and as high as 40oC (or greater). In BC, C. lunula has been released and found established and dispersed within the Bunchgrass, Interior cedar hemlock, Interior Douglas-fir, and Ponderosa pine biogeoclassification zones as well as on the fringes of Montane Spruce. It is too early to determine the status of the release made in the Coastal western hemlock zone.
History:	The first C. lunula releases began in the 1960's. Several attempts were made to establish them in and near Kamloops. Larvae were seen later that same year, but not thereafter. In the 1980's rearing plots were established to increase populations for redistribution. Collections taken from the rearing plots were used to create several new sites in the Southern Interior. In 1997 the first field collection was made in BC.
Field Results:	Since 2000, larvae sightings have become common from late-May and early-September, in varying habitats throughout the Southern Interior. The moth is establishing and dispersing along road edges, gullies, and occasionally near water. A common observation at established sites was the absence of excessive plant litter. Large volumes of plant litter may inhibit larvae movement between plants. During the hottest parts of the day, larvae are found in slightly shaded areas out of direct sunlight. After extended periods of hot weather, the larvae appear to completely avoid dried plants, preferring adjacent green plants. In 2008, a dispersed population found on a mixed stand of yellow toadflax and Dalmatian toadflax was collected from the North Thompson and released onto Dalmatian toadflax on Vancouver Island.
Notes:	At the early treatments near Kamloops, cattle consumed young larvae and 90% of the pupae were parasitized by Dibrachys cavus, compounding slow establishment.

	Chaetorellia acrolophi (White & Marq.)
Attacks:	Spotted knapweed, Diffuse knapweed
Agent Type:	Seed feeding fly
Origin:	C. acrolophi populations in BC originated in Valais, Switzerland.
Adult:	Adults are 4-5mm long and have orange-yellow coloured abdomens with overall spotting. Their wings are clear with light-brown bands and their eyes are bright green. The flies emerge in early-June, coinciding with knapweed bud formation. Mating occurs immediately and oviposition starts within two days. Females lay eggs during their entire life span, depositing an average of 69 eggs each. Eggs are placed individually or in small groups of 2-4 underneath the bracts of unopened 4-5mm diameter floral buds. Within a lab environment, adults survive up to four weeks; 17 days in the field. There are two complete generations (eggs to adults) and part of a third generation (eggs to larvae) each year.
Egg:	The 0.9 x 0.2mm shiny white, elongated eggs have a long filament which is thickened at one end. Eggs incubate for 4-5 days.
Larva/Pupa:	The larvae remain white coloured through the three larval instars which last 10-15 days. The first instar penetrates the bud horizontally and moves towards the bud centre, feeding on immature florets until it reaches the developing seeds. Second and third instars feed on bud contents. Mature larvae prepare a puparium, arrange it vertically and pupate. There are usually two generations per year, but a rare third generation is possible when ideal habitat conditions are present.
Overwintering:	The third instar larvae overwinter in seedheads and pupate the following spring.
Location & Efficacy:	Larvae feed on floral buds, sometimes consuming the entire contents, which significantly reduces seed production. Unlike other seed feeders, the larvae do not create a gall. Chaetorellia acrolophi is most effective in areas with low density knapweed which is less preferred by other seedhead feeders. The highest rate of attack occurs on sites that do not have Urophora species present.
Habitat:	Specific C. acrolophi habitat has not been determined. It has the ability to seek out isolated sites which are normally avoided by competing bioagents. In its native environment it does not build up high populations in thick stands, showing a desire to be among widely spaced plants with mixed vegetation. Initially it was predicted that C. acrolophi preferred very dry south-facing slopes, but this may not be the case in North America where establishment has been found in moist areas of Montana and Oregon. Native European distribution is from Spain and the European Alps, east to northern Greece, and north to southwestern Russia. It occurs in the southern regions of Austria, France and Switzerland, the central region of Turkey, the eastern section of Romania and the east and central portions of Hungary. In western Switzerland, C. acrolophi densities are greatest on steep, dry, south slopes. In BC, C. acrolophi has been released into the Bunchgrass, Interior cedar-hemlock and Interior Douglas-fir biogeoclimatic zones. Establishment and dispersal has occurred in the Interior cedar hemlock and Interior Douglas-fir zones.
History:	In 1991 a small number of C. acrolophi were released near Kamloops into a bunchgrass habitat and another population was released into a propagation tent. Between 1992 and 1995 several more releases were made as larger populations were made available and shipped to BC.
Propagation Results:	The tented population failed to establish sufficient numbers for collection and in 2001 the tent was dismantled.
Field Results:	C. acrolophi was originally released into relatively thick patches of knapweed. It is believed that the agent may have dispersed, seeking its preferred widely spaced infestations. As knapweed infestations continue to reduce in vigour and density, it is presumed that C. acrolophi may become more evident. Establishment was found at one site soon after its release, but subsequent monitoring had shown no recoveries until 2008. Seedhead sampling in May determined that C. acrolophi has established at at least one release site and has also been found dispersed at two locations in the southern interior.
Notes:	Chaetorellia acrolophi may also attack purple starthistle (C. calcitrapa) and squarrose knapweed (C. virgata spp). When U. affinis is in high densities, C. acrolophi is a weak competitor.

	Cochylis atricapitana (Stephens)
Attacks:	Tansy ragwort
Agent Type:	Root crown feeding moth	Previously Known As:	Epoecilia atricapitana
Origin:	The C. atricapitana released in BC derive from Spanish populations obtained from Australia.
Adult:	Cochylis atricapitana are very delicate, fragile moths, 3mm long with a 7mm wingspan. Forewings are tan coloured with irregular brown, black and grey marks. A dark tuft of scales project upward from behind its head. The first generation females lay eggs individually onto veins on the underside of bolted stalk leaves. Capable of multiple generations each year, it is more common to find adults from May to June and again from July to August. The second generation females oviposit eggs in the fall onto rosette leaves. Both generations will oviposit about 150 eggs each. In the south of France, seven generations are produced. During the day, adults remain close to the ground near or on the plants, taking flight near dusk, and becoming active during the night. The sex ratio is 1:1.
Egg:	The oval, flat eggs, 0.5 x 0.3mm, are initially translucent white and gradually change to yellow. Developing larvae can be observed through the egg surface. Eggs incubate for five days.
Larva/Pupa:	New larvae are creamy white with a black head, the body darkening to tan as it ages. There are five larval instars, which develop in 33 days when temperatures are 24°C. First generation larvae mine the leaf and mid-vein, then move to stems where they will either mine through the stems or move upward and feed on shoots and flowers. Second generation larvae move from rosette leaves downward to the root crown, feeding and developing until hibernation. Evidence of presence can be detected by black feces located near the base of small central rosette leaves. If they overwinter in the fourth instar, feeding resumes the following spring, as they make their way upward into the lower central shoot area to pupate. If they overwinter in the fifth instar, they move to the soil and pupate the following spring. Pupae are light brown, 7 x 1.5-2.0mm and are enclosed in a creamy white silken cocoon that changes to pink. As the new adult exit, it discards its pupal case at the exit point, which may occur from the plant crown, stem or bud.
Overwintering:	They can overwinter as fourth instar larvae or full grown fifth instar.
Location & Efficacy:	Larvae feeding in actively growing stems will causethe stems to thicken, and the leaves to bunch, which interferes with floral development. Larvae mining roots and older stems can kill the plant.
Habitat:	C. atricapitana is adapted to a wide variety of habitats where tansy ragwort grows, including high elevations. It is recommended for areas with early winters, where the season may be too short for other controlling agents such as Longitarsus spp. Native distribution includes North Africa, western and central Europe, England, Sweden, Poland, the former Czechoslovakia and south Russia. In southeast Europe it is most common in west-coast locations when tansy ragwort is abundant. In BC, C. atricapitana has been released into the Coastal Douglas-fir, Coastal western hemlock and Interior Douglas-fir biogeoclimatic zones. Establishment and dispersal is restricted to the Coastal Douglas-fir and Coastal western hemlock zones. No establishment has been found outside the coastal habitats.
History:	C. atricapitana was first released in the Fraser Valley and near Nanaimo in 1991. Release efforts continued throughout the Coastal Forest Region until 1996. In 1994, 70 larvae infested plants were transplanted into a tansy ragwort infestation in the Okanagan. The moth easily established in the coastal climate, but did not establish in the southern interior. In 2008, a second attempt was made by transferring 59 larvae infested roots into the Okanagan.
Field Results:	In the lower mainland, larvae and adults can both be found in early August. No establishment of C. atricapitana has occurred at southern interior locations. The adults do not feed on the plants and are extremely small and difficult to locatetherefore monitoring larvae is preferred over sweeping or observing adults.
Notes:	C. atricapitana can exist with L. jacobaeae on the same plants because they feed in different parts of the root.

	Eteobalea intermediella (Riedl.)
Attacks:	Dalmatian toadflax, Yellow/Common toadflax
Agent Type:	Root feeding moth
Origin:	E. intermediella populations in BC originated in Serbia.
Adult:	Adults have yellow heads and black wings marked with gold metallic flecks. Their normal wingspan is 16 to 18mm, but decreases when the plant roots become crowded during larval development. The first adults emerge in the spring. Mating begins immediately after adults appear. The females emerge with 60 developed eggs and may produce up to 180. The eggs are oviposited in loose strings of three to eight into axils or on rough surfaces on the soil within 10cm of the plant. They remain non-feeding during their entire adult life, which normally lasts two weeks in the field (up to 4 weeks in the lab). Adults are weak fliers, taking short flights to seek host plants. In their native range, Eteobalea intermediella are capable of two or more generations. When two generations occur, the adults emerge in late spring. When multiple generations occur, the adults' flight period will overlap.
Egg:	The 0.3 x 0.5mm white eggs have a network of irregular meshing lines (reticulate), differing from E. serratella eggs which have parallel lines (striate). Incubation lasts 9-10 days at 25°C, changing from white to yellow. Most eggs hatch during the night and early morning. Just prior to hatching, two red eye spots can be seen inside the egg. E. intermediella eggs require high humidity and are more prone to fungal attack than E. serratella.
Larva/Pupa:	The newly hatched larvae move to leaf axils or other soft tissue points where entry is easy. They can mine all parts of the roots. The feeding tunnels are lined with a silken tube. Multiple larvae can develop on a single plant, but the number depends on the plant and root size. In studies, up to 28 (19 larvae, three pupae and six pupae casings) were present on narrow-leaved Dalmatian toadflax, whereas only one or two were common on yellow toadflax (this test plant study did not include Dalmatian toadflax). Pupation occurs within the silk tunnel. When temperatures remain at 20°C, the new adults emerge in 20 days. These will go on to produce a second generation of larvae which will then overwinter. Excess soil moisture negatively impacts larval development.
Overwintering:	Second (or later) generation larvae overwinter in roots.
Location & Efficacy:	The feeding larvae, notably the later instars, consume and destroy a significant amount of nutrient reserves, which reduce the upper vegetative and reproductive parts. Attacked plants will produce fewer stalks, leading to decreased seedling production.
Habitat:	The distribution of Dalmatian toadflax growing in BC is beyond the native range for E. intermediela and its most northern latitude limits, but the climates are equivalent. It is probable that E. intermediella will colonize Dalmatian toadflax in BC, but it is not expected to survive elsewhere in Canada. Preferred plants have a 4mm diameter root. Moist soils are not suitable. In Europe, E. intermediella has a wide geographic range, is common within the Dalmatian toadflax distribution and is frequently found throughout the western Mediterranean countries, east to Iran, into southern Russia and central northern France. In BC, E. intermediella were released only into rearing tents in the Bunchgrass biogeoclimatic zone. Long term populations did not develop and no field releases have been made; habitat preferences cannot be clearly defined at this time.
History:	Unsuccessful rearing attempts were made using propagation tents between 1991 and 1998.
Propagation Results:	In rearing tents, small populations persisted from 1999 until 2002. In 2004 the tents were dismantled after not seeing any further evidence of survival.
Notes:	E. intermediella can exist with seed feeders Brachypterolus pulicarius and Rhinusa species. E. intermediella populations from Novi Beograd, Serbia may be best suited for south central British Columbia.

	Eteobalea serratella (Treitschke)
Attacks:	Dalmatian toadflax, Yellow/Common toadflax
Agent Type:	Root feeding moth
Origin:	E. serratella populations released in BC originated in Serbia and Italy. The population from Serbia was reared on Dalmatian toadflax.
Adult:	The moths have sender bodies measuring 8-9mm long. Adults are black with yellow heads. Their black wings are covered with golden metallic flecks. Their normal wingspan of 16-18mm decreases in crowded larval development conditions. Adults begin to emerge in early-summer and live for about two weeks in the field (survival in the lab is up to four weeks). During this lifespan, they do not feed. Adults are weak fliers. Females emerge with up to 60 developed eggs and begin oviposition immediately. They will lay up to 180 eggs close to the stem base. The moths possess a good host finding ability, seeking new sites within short flights.
Egg:	The white, 0.3 x 0.5mm eggs change to yellow as they mature. Eteobalea serratella eggs have parallel lines (striate), differing from E. intermediella eggs which have a network of irregular meshing lines (reticulate). Eggs hatch in 9-10 days at 25°C, most frequently during the night or early mornings. Just prior to hatching, red eye spots can be seen inside the egg. E. serratella eggs show less susceptibility to fungal attack than E. intermediella.
Larva/Pupa:	The newly hatched larvae bore into the plant at leaf axils or other soft tissue points where entry is easiest. The larvae move downward to the root, feeding into the root crown and on small roots. They can mine all parts of the roots. The tunnels are lined with a silken substance. Multiple larvae can develop on a single plant, but the number depends on the plant and root size. Complete larval development takes 11 months and when mature they will be a maximum of 12mm long. There is no rest period required for E. serratella as the larvae will continue to feed throughout the winter if temperatures and humidity are optimal. The larvae pupate within the silk tube. Excess soil moisture has a negative impact during larval development.
Overwintering:	E. serratella overwinters in the larval stage and will continue to feed and develop as long as ideal conditions are present.
Location & Efficacy:	The larval stages, notably the later instars, cause destructive control. Overall plant production is reduced when plants have been attacked by E. serratella. Seed weight is most significantly reduced and the flowering and seed producing periods are shortened. Continued attack reduces the plants' ability to develop normally, and decreases new seedlings. In dry conditions yellow toadflax can be killed.
Habitat:	Potentially suitable areas are grasslands, pastures, cropland and road or utility right-of-ways. E. serratella shows a preference for yellow toadflax over narrow-leaved Dalmatian toadflax. In its native habitat, E. serratella's locations are restricted to dry terrestrial sites, favouring the northern Eurasiatic areas that coincide with their host plant distribution. In BC, E. serratella were released in the Bunchgrass biogeoclimatic and Interior Douglas-fir zones. Insufficient populations developed to allow for field releases and further study; their preferred habitat is not known at this time.
History:	Two unsuccessful attempts to propagate E. serratella moths in rearing tents, on Dalmatian toadflax and yellow toadflax, were made in 1992 and 1995.
Propagation Results:	A small population persisted through the 1997 season, but nothing was found the following year. In 2004, yellow toadflax plants with larvae infested roots were transplanted into a rearing tent and are currently under observation.
Notes:	E. serratella can exist with seed feeders Brachypterolus pulicarius and Rhinusa antirrhini (there is an adventive variety found on yellow toadflax). Yellow toadflax sites in south central BC should be treated with E. serratella from Rome, Italy.

	Hadroplontus litura (F.)
Attacks:	Canada thistle
Agent Type:	Stem feeding weevil	Previously Known As:	Ceutorhynchus litura
Origin:	H. litura populations released in BC originated in France, Germany and Switzerland.
Adult:	The adult weevils are 3-4mm long with a prominent long rostrum (nose). Their oval bodies are completely covered with whitish hairs. Their upper back is dark grey to black and marked with a distinct white 'T' or cross-like formation. When the weevils are on the soil surface, the mottled markings camouflage them. In cool climates the adults appear in early-spring, from March to early-June and will mate and produce a generation that emerges in August and September. In the warmer areas, adults can remain active overwinter and even year round from August through to the following May, June and occasionally July, depending on habitat. In either case, the mating season remains the same. Oviposition starts when thistle rosettes first appear in the spring, between March and mid-May, and continues for 4-6 weeks. The adult feeding on the leaves creates cavities where the female will deposit the eggs. The females lay the eggs individually or in groups of 2-5 into the cavities into plant tissue or in the mid-vein on the underside of leaves. Each of the females will lay up to 120 eggs. The preferred oviposition hosts are smaller plants usually up to 5cm tall. When the plants reach beyond this height they become unsuitable.
Egg:	The eggs hatch in 5-9 days.
Larva/Pupa:	The larvae are whitish coloured with light brown, pointed heads. There are three larval instars which all occur within the plant. The first instar mines down the leaf vein and into the plant stem. If the plant has already started to bolt, the larvae will mine up the stem and feed on the inner pithy area. If the larvae enter non-bolting plants they will mine downward and feed on the root crown and occasionally the root. The plants react to the intruding larvae by producing "wound tissue" (a callus growth), which the larvae feed upon. In vigorous growing plants, the callus can smother up to two larvae, but if multiple tunnels are present, the plant stem bases will swell and develop woody galls which instead can kill the plant. By the end of the third instar the mature larvae move to the soil to pupate in an oval cocoon made from soil particles. Pupation lasts two to three weeks before new adults emerge in late summer and fall. Cool spring weather delays the plants' bolt, maximizing larvae feeding and resulting in better plant control.
Overwintering:	In cool climates the adult will overwinter in the soil and leaf litter, but in warm climates there is no rest period and the adults can remain active all winter.
Location & Efficacy:	To kill the host plants, the larvae need to begin feeding in early-spring, before bolting has started. Less impact is noticed if the attack comes after the plants have already begun their active spring growth. The overall plant height is not affected by the larvae mining. Secondary insects or pathogens attacking the plants are often more harmful than Hadroplontus litura. When the larvae create the exit hole for pupation, they provide an entrance for other organisms. Adult foliar feeding on upper and lower leaf surfaces creates a window effect.
Habitat:	In North America, H. litura will establish on thick dense Canada thistle stands, preferring bare soil surfaces between plants, and avoiding sites with competing plants. Spring flooding can be tolerated. Locations with long cool springs, which delay the plants bolting, are better suited than those that encounter rapid gains in heat. The weevils' native distribution occurs in Atlantic Europe, from the southern parts of France to southern Scandinavia. In BC, H. litura has been released into the the Bunchgrass and Coastal Douglas-fir biogeoclimatic zones. Establishment has been found in the Coastal Douglas-fir zone. Efforts to determine the status of the site in the Bunchgrass zone is ongoing.
History:	H. litura was introduced to BC within a protected ecological reserve in 1975 at the lower mainland, and in 1987 a second treatment was made on Vancouver Island. The earliest treatment site was noted to be established within one year. In 1994, an attempt to transfer larvae/pupae infested plants from Richmond to Kamloops was made.
Field Results:	In 2008 the earliest release site was revisited. The area was fenced and most of the thistle clipped and mowed. Despite the mechanical control methods used here, a single adult was located. There is a possibility that the agent dispersed to nearby thistle patches as the plants became less abundant. In 2002, an unidentified dead beetle pupae was found inside a plant root at the Kamloops site. At this same location, in 2003 and 2004 stem mining and frass was observed. Foliar feeding, stem tunnelling and one dead larva was found the following spring (2005). The results are inconclusive at this time.
Notes:	Studies have shown H. litura capable of infesting 80% of a Canada thistle site in 10 years and can disperse 9km in 10 years. In Ontario, H. litura was found in higher quantities on plants infested with Puccinia punctiformis. It is not known if the weevil prefers plants attacked with the rust, or if the weevil may be a vector. Plant density appears to decline when attacked by both H. litura and P. punctiformis at the same time.

	Hyles euphorbiae (L.)
Attacks:	Leafy spurge, Cypress spurge
Agent Type:	Foliar feeding moth
Origin:	H. euphorbiae released in BC came from populations reared on cypress spurge in Ontario. The original stock came from eastern Germany.
Adult:	The large brown hawk moths have colourful pink, white and black markings on their wings that measure up to 8cm across. Their markings are distinct, but can be easily confused with similar, native species. A modified mouth part enables them to perceive the sound of bat cries. The moths can be located in the field from late-May through June (depending on location) and again in August and September and feed on the plant nectar of funnel-shaped flowers, hovering like a hummingbird. Adults are strong fliers. The females begin to lay eggs in May and continue to do so through to mid-September, coinciding with the spurge bloom. Each female will oviposit 70-150 eggs singly or in clusters up to 50 onto leaves and floral bracts.
Egg:	The eggs are green and measure 1mm in diameter. The outer egg cover remains clear during incubation which allows for observation of the development process within.
Larva/Pupa:	The larvae have five instars that take 2-3 weeks to complete. Each instar has distinctly different colouring and patterns. The first is dark black or black-green, with 6 legs and 10 prolegs. The first instars spin thin thread webs to keep themselves from falling to the ground. The second instars' colour changes to green with white spots. At two weeks, the larvae are in the third instar and will have enlarged to 2-3 gm and changed their colour to green, black and red with yellow spots. The larvae are mature when they have enlarged to 11cm long and changed their colour to a darker combination of the previous, but with a crimson stripe along its back and an added prominent black-tipped, crimson horn. The larvae appear during June and early-August and begin to feed on the spurge foliage. They are aggressive feeders that will actively travel when hungry and prior to pupation. Feeding slows when temperatures drop below 15°C. The mature larvae burrow into the soil or plant litter to a maximum depth of 8cm. Soil and loose materials are cemented together to form a water-proof chamber. Eggs that hatch early will complete pupation in 15-20 days and the others will overwinter inside the chamber, which can tolerate temperatures to -21°C. The young pupae are greenish-white coloured with soft bodies, whereas mature pupae are pale brown. Pupae will measure 4-5cm long. The larvae stage is prone to ant predation. Active feeding larvae accumulate toxins in their skin which deters enemies, but this protection does not persist during the pupae stage and results in high predation by mice and other small rodents.
Overwintering:	It will overwinter as a pupae in a water-tight pupal chamber within the soil. At this stage it will be most vulnerable to predation.
Location & Efficacy:	The larvae feeding can cause complete defoliation of plants. Foliar feeding uses up plant nutrient reserves and reduces the plant vigour. This agent alone is insufficient for spurge control, but can be combined with the effects of other agents.
Habitat:	Since 1992, larvae sightings have become common in southern Alberta and are alleged to be the result of dispersals from Montana. In North America, established sites are associated with habitat that offers some tree shelter. They require thickly growing infestations. Birds, small animals and rodents will feed on the pupae, so sites free from these or with fewer predators are better suited. Avoid sites with large ant populations. Hyles euphorbiae is established in Ontario on cypress spurge, which was the source plant for redistribution in North America. Originally it was predicted they would require relatively warm winters, but establishment in Montana has shown otherwise. Its native distribution is from south and central Europe and into central Asia. In BC, the only release site is in the Interior Douglas-fir biogeoclimatic zone. No confirmed sightings have been determined at this time.
History:	Two H. euphorbiae releases were made on leafy spurge in the East Kootenays in 1966 and in 1967. Subsequent monitoring indicates no establishment was found. Efforts to locate H. euphorbiae are ongoing.
Field Results:	In the spring of 2005 there was a possible adult sighting on leafy spurge growing in the vicinity of the original release area.
Notes:	At 32°C, a generation completes development in six weeks. It is possible that most Canadian temperatures may be too low for this agent. Abundant populations in the are prone to a viral disease.

	Hylobius transversovittatus (Goeze)
Attacks:	Purple loosestrife
Agent Type:	Root feeding beetle (weevil)
Origin:	The H. transversovittatus releases made in BC originated in Germany.
Adult:	Hylobius transversovittatus are red, stout weevils that measure 8-13mm long. The adults will appear when plants are about 20cm tall and will be present from April through October. They remain nocturnal, feeding at night until hibernation. Adults are long lived, often two or three years or more. They are slow to populate and will produce a single generation every one or two years. The adults that emerge by mid-August will oviposit the same year, those emerging later will overwinter. Females deposit the eggs in the soil near the host plants and occasionally onto plant stemsa just above the soil. During the yearly oviposition cycle, each female will lay up to 100 eggs, but usually only one or two are laid each day. The females can lay up to 300 eggs over their life span. Congregations of adults are common in the field environment.
Egg:	The pale yellow, oval eggs hatch within two weeks.
Larva/Pupa:	The larvae are cream-coloured with dark brown head capsules. They bear a resemblance typical to those of other beetles/weevils by maintaining a crescent or "C" shape. The larvae hatching from eggs laid in the soil feed on root hairs and then burrow into the roots. Larvae that hatch from eggs laid on the stem mine the shoots before moving down to the roots. Root feeding can continue for two years. Larvae development will be prolonged to two years if the plants become flooded. During each period of flooding, larval development is interrupted, and resumes when the water subsides. Mature third instars move to the upper portion of the root crown where pupation commences. The duration from egg to adult takes one or two years.
Overwintering:	H. transversovittatus can overwinter in any of its life cycle stages: as eggs in the soil or plants; as larvae or pupae in roots; or, as adults in soil litter.
Location & Efficacy:	Larvae feeding may cause death to attacked plants. Plants with small rootstocks can be killed within two years when attacked by two or more larvae. Large rootstocks require a higher number of larvae to achieve the same result. Adult feeding on leaves produce ragged leaf margins.
Habitat:	H. transversovittatus is capable of tolerating a wide variety of habitats and environmental conditions. Sites free from prolonged or frequent flooding are best suited. H. transversovittatus has excellent host plant searching capability, which enables this agent to disperse easily to create new colonies. In its native distribution in Scandinavia it is most effective on sites not controlled by Galerucella spp. In BC, H. transversovittatus is established in the Coastal Douglas-fir biogeoclimatic zone. Significantly more field work is required to determine its desired habitats. The close proximity to salt spray and tides indicate that it may have a tolerance for saline conditions. Establishment in other Canadian provinces is variable; established in Alberta in a rearing garden, but its status is unknown in Manitoba, Ontario, and Nova Scotia.
History:	A single release of H. transversovittatus was made in 1994 at the lower mainland in a tidal flat, within a protected ecological reserve. The release came from Europe through co-operators in the . Forty potted plants infested with eggs and larvae were transplanted at the release site. The treatment was made in July and during this same year high tides and a severe storm hit the site causing extreme devastation. Establishment was not confirmed until 2008 when a single larva was located in a plant root.
Field Results:	The release site was suspected to have not established, based on the severity of a winter storm that destroyed the area shortly after the release was made. The site was quickly revisited in 2001, but no plants were excavated and the foliar feeding found at the time was attributed to Galerucella spp. In 2003 another attempt to locate the beetle was tried and 15 plants were excavated and dissected, but no larvae was found. In 2008 a larva was found on the second plant excavated.
Notes:	H. transversovittatus is difficult to handle and expensive to rear. Plant vigour and density controls the bioagent population.

	Lobesia euphorbiana (Freyer)
Attacks:	Leafy spurge, Cypress spurge
Agent Type:	Leaf tying moth
Origin:	L. euphorbiana released in BC originated in populations collected from the host plants Euphorbia lucida and E. seguierana in Italy.
Adult:	Adults are mottled yellow, brown and reddish coloured. Wingspan is 10-14mm. First generation adults begin to appear in the field by mid-June, mating and egg laying begins immediately, occurring mainly at dusk and dawn. There are two generations per year, and possibly three in southern Ontario. Females lay an average of 55 eggs each, which are laid individually onto lower leaf surfaces. Adults live 3-7 days.
Egg:	Eggs are translucent yellow and measure 0.77 x 0.62mm. Eggs are highly fertile and very few fail to hatch.
Larva/Pupa:	Young larvae are pale green and, when mature, are almost black. Newly hatched larvae move towards terminal leaf tips and tightly tie leaves with silky webbing. There are normally four instars, head capsule measurements are used to determine each. Up to five instars can occur when food sources are low. Terminal ties yield larger larvae/pupae than lower stems. Larvae also develop slower on lower lateral shoots than on the terminals. Several larvae can begin in one tie, but only one completes development. The others are either killed or forced out where they will develop slower with five instars. However, larvae and pupae can exist together in a single tie. When the ties are opened the larvae agitate easily and lose vigour. They are not cannibalistic unless they become short of food. Larvae prepare for pupation by moving to the leaf tip where they spin a thick web. Fresh pupae are pale green, changing to browna just before emerging. At 21-24°C and 16 hour days, pupation is completed in 26 days, so the development from egg to adult (second generation) is completed in 36 days.
Overwintering:	The second generation pupae overwinter within folded leaves in soil litter.
Location & Efficacy:	Larvae enclose themselves inside tied terminal leaves where they consume the bud and prevent flowering. Repeated heavy attack eventually kills the plant. Vacated ties attract thrips and aphids, creating preferred locations for secondary attack.
Habitat:	Lobesia euphorbiana prefers sites which are warm to hot during the summer. Complete development requires high temperatures. It inhabits fringe forested areas, tolerating shade. They require active growing plants with high nutrient quality usually found growing in mesic conditions. They do not do well on weak stands growing in poor soils. It commonly establishes near water. The native range of L. euphorbiana is from south and central Europe to the Ukraine. In BC, L. euphorbiana has been released into and found established in the Bunchgrass, Interior Douglas-fir and Ponderosa pine zones. The moths appear to be dispersing well in the southern interior.
History:	In 1987, an attempt to propagate L. euphorbiana was tried in a greenhouse, but was not successful. In 1990 the first field release was tried near Kamloops. This release established collections commenced in 1993. This same release site is still currently used for collection and is the population source for all the releases redistributed in BC since 1993.
Field Results:	Ties and larvae have been located in the field from late-May to early-August which persist after the adults vacate. The density of ties at the established sites appear to fluctuate with the plants' density and vigour.
Notes:	Sometimes gall terminals made by Spurgia esulae will be used by L. euphorbiana.

	Longitarsus flavicornis (Steph.)
Attacks:	Tansy ragwort
Agent Type:	Root feeding flea beetle
Origin:	L. flavicornis released in BC is from stock that originated in Britain, Switzerland and Italy.
Adult:	Adults are reddish-brown, but darken as they age. They are 2.5-3.5mm long and have enlarged rear legs that enable them to leap great distances. Adults emerge in early-summer (May-June), feed a short time and rest until late-summer or early-fall (September). When they reappear later in the season they feed intensely. The shortened days activate sexual changes in both males and females. In areas where continuous long days occur, 99% of beetles will not become reproductive. Females stop dispersing once they become reproductive in the fall. Oviposition is delayed until weather conditions are suitable, which usually begins in October and continues until January. Sites which are too cool inhibit oviposition. Each female will lay between 500 and 1000 eggs. Eggs are deposited up to 4mm deep near plant roots with a small percentage laid on petioles.
Egg:	Eggs are oval and measure 0.66mm x 0.3mm. Surface-laid eggs experience partial dehydration, but overall are less vulnerable to dry conditions than those of Longitarsus jacobaeae. Initially yellow, they darken during the 14-16 day incubation period. At 8°C, eggs hatch in 88 days or in 14 days at 25°C.
Larva/Pupa:	White slender larvae hatch from eggs and begin to feed on the root crown. Newly emerged larvae are 1.5mm long, growing to 2-4mm long over 8-14 weeks. L. flavicornis does more external root feeding than L. jacobaeae, often consuming the entire outer layer and root cortex. The feeding cause the plants to have poorly developed, deeply mined and scarred roots. On the root crown they feed into the cortex, seldom feeding into the core. In crowded or flooded conditions, they will feed on crowns and within the petioles of lower leaves. Overwintering (November through May) larvae distribute to petioles, root crown, roots and in the soil. Mature larvae move to the soil to pupate, seldom remaining near the plants. By March, most larvae are in the third instar.
Overwintering:	Normally they will overwinter as larvae in the soil, but in Canada they are expected to also overwinter as eggs.
Location & Efficacy:	Adults create ragged shot-hole feeding. Larvae feeding on roots can kill small rosettes, heavy attack is required to impact large plants. L. flavicornis feeds more aggressively on external root layers than L. jacobaeae. It often consumes all the outer epidermis and cortex, leaving only the central core intact.
Habitat:	L. flavicornis requires sunny locations with high density plants growing in well drained soils. It does not tolerate flooding, heavy shade or elevations over 400 m. Areas with long, moist autumns are required. It requires warmer temperatures and a milder climate than L. jacobaeae. L. flavicornis has a native distribution area south of latitude 52°N in England to east of longitude 5° in Siberia. It occurs in coastal areas of Morocco and Algeria, throughout Spain and southwest France. It co-exists with L. jacobaeae from south England to Paris, France. It primarily occurs in climates where winter temperatures average 0°C, coinciding with the most southern limit of tansy ragwort. In BC, L. flavicornis is probably released at its most northern limit, in the Coastal Douglas-fir biogeoclimatic zone.
History:	L. flavicornis was released during the 1970's in Nanaimo as 10% of a mixed population with L. jacobaeae. There has been no attempt to separate the collected specimens to determine if one or both species are established. It is acceptable to consider that the field populations may be of mixed populations.
Field Results:	Field collections taken from the single L. flavicorinis release area have not been sorted, so mixed populations could occur at subsequent release locations.
Notes:	Combined efforts with Tyria jacobaeae offer excellent control as each agent has a preference for plant size.

	Longitarsus jacobaeae (Waterhouse)
Attacks:	Tansy ragwort
Agent Type:	Root feeding flea beetle
Origin:	L. jacobaeae releases were brought to BC via the USA, and originated in Britain and Italy.
Adult:	Males are 2.5-3.5mm long and females are 1mm larger. Their colour changes from initially golden-tan to light golden-brown when mature; further changing to dark brown when old. They have enlarged rear legs that enable them to leap great distances. Adults emerge in early spring to early summer (May-June), feed a short time and rest until late-summer or early-fall (September). When they reappear later in the season they feed intensely. The shortened days activate sexual changes in both males and females. In areas where continuous long days occur, 99% of beetles will not become reproductive. Females stop dispersing once they become reproductive in the fall. Oviposition is delayed until October when ideal habitat will offer 3.5 months of suitable weather. Sites which are too cool will inhibit oviposition. Mating and oviposition continues until sub-zero temperatures arrive. Each female will lay between 500 and 1000 eggs, which are deposited individually at the root crown or leaf petiole base.
Egg:	Eggs are oval and measure 0.66mm x 0.3mm. Initially yellow, they darken during the 14-16 day incubation period. Eggs are vulnerable to dry conditions, so long moist autumns are necessary.
Larva/Pupa:	White slender larvae hatch from eggs and begin to feed on the root crown. Newly emerged larvae are 1.5mm long, growing to 2-4mm long over 8-14 weeks. Development continues on the outer root layers, often penetrating into the root core. Long grooved formations within the roots are the result of feeding on the outer layers. In crowded or waterlogged conditions, they will feed on crowns and within the petioles of lower leaves. Mature larvae will move to the soil to pupate, doing so up to 5cm from the plant.
Overwintering:	Typically, larvae overwinter in plant roots. Eggs also overwinter in some populations. In mild climates adults can hibernate during the winter months.
Location & Efficacy:	Adults create ragged shot-hole feeding causing little impact to the plant. Larvae feeding on roots can kill small rosettes, but heavy attack is required to impact large plants.
Habitat:	Longitarsus jacobaeae requires sunny locations with high density plants growing in well-drained soils. It does not tolerate flooding, heavy shade, or elevations over 400m. In the Pacific Northwest it has not established east of the Cascade Mountains. Areas with long, moist autumns are required. L. jacobaeae has a native distribution from Ireland to Siberia and Tibet. It is common to areas in central Italy, Sardinia, south Scandinavia, and from Ireland to east Georgia. In Western Europe, it is limited to latitudes between 40-57°N, further restricted in the Ukraine to south of 50°N. In BC, L. jacobaeae has been released into the Coastal Douglas-fir, Coastal western-hemlock and Interior Douglas-fir biogeoclimatic zones. Establishment is restricted to the lower mainland and coastal environment, remaining unsuccessful in the south Okanagan. Dispersal throughout the Coastal Region is wide spread.
History:	The first L. jacobaeae population was brought to BC in 1971. They arrived from California and were divided for lab rearing at UBC and into an open release in Abbotsford. In 1976 the first field collections commenced and continued until 2001 and were released in the Coastal Forest Region. Several unsuccessful attempts were made to establish a population in the Okanagan. Assisted redistribution efforts continued until 2005.
Field Results:	A release of 1092 beetles onto a site in Nanaimo had 97% of plants attacked, with an average five larvae/root in eight years. In coastal habitats, adults, larvae, and foliar feeding can be observed at low levels by early August. In the Fraser Valley, overwintered adults have been observed on plants in April.
Notes:	Combined efforts with Tyria jacobaeae offer excellent control as each agent has a preference for plant size, attacking the multiple generations of tansy ragwort on a site. A study of 42 sites in Oregon had 93% decrease in tansy ragwort plants in six years.

	Longitarsus quadriguttatus (Pont)
Attacks:	Hound's-tongue
Agent Type:	Root feeding flea beetle
Origin:	L. quadriguttatus populations released in BC originated in Austria and Hungary.
Adult:	Adults are 2.4-3.0mm long, shiny black flea beetles with long antennae. Each wing cover has two reddish spots, which vary in size and shape. Adults are capable of jumping great distances and do so when disturbed. Adults begin to emerge from the soil in late-spring and can be present all summer into the fall, but the average life span is 41 days for males and 67 days for females. Weather does not appear to alter their emergence period. Adults feed, mate and oviposit 4-7 days after emergence. Each female lays an average 280 eggs, depositing them at petiole bases, on roots crowns or into the soil within 2cm from first year rosettes.
Egg:	Eggs are yellow to light orange coloured, elliptical, measuring 0.6 x 0.2mm. Incubation takes up to 14 days.
Larva/Pupa:	Larvae emerge and begin feeding on secondary roots and the cortex of the main tap root. There are three larvae instars, which are distinguished only by head capsule size. By 35-40 days after hatching, 40% will be in the second instar and 60% will be in the third instar. It prepares for winter hibernation by emptying its gut. Feeding and development resumes the following spring. Larvae do not appear to transfer to other roots, so first year rosettes are necessary for complete development. Mature larvae exit the roots in April and pupate in the soil.
Overwintering:	Immature larvae overwinter in plant roots.
Location & Efficacy:	Adults feed on foliage, making pin-prick like holes over the entire leaf, contributing limited control. Larvae control the invasive plant by mining roots. In European rearing facilities, no plants survived larvae feeding, and the number of plants in BC rearing tents were significantly reduced.
Habitat:	The preferred Longitarsus quadriguttatus habitat is currently being studied and shows a preference for hot sites. Its expected range is restricted to areas with a mild continental climate, limiting it to the southern regions of BC, AB and ON. The L. quadriguttatus native geographic range occurs in central Europe where hound's-tongue is established. The flea beetle is absent in Scandinavia, the Netherlands and Britain. In BC, releases have been restricted to hot dry sites located in the Bunchgrass, Interior Douglas-fir and Ponderosa pine biogeoclimatic zones. Adults have been observed at sites located in the Interior Douglas-fir and Ponderosa pine zones, but not in the Bunchgrass zone. At the hottest south Okanagan locations, sites with filtered shade have shown better establishment than those in the open. Releases made in open hot sites may be better suited for the Interior Douglas-fir zone whereas releases made in filtered, shaded sites may be best suited for the Ponderosa pine and Bunchgrass zones.
History:	L. quadriguttatus was first released in the lower, central portion of the southern interior in 1998 and into a propagation tent. Open field site assessments are ongoing.
Propagation Results:	In 2000, sufficient populations established in the propagation tents and collections were transferred to field sites in the southern interior. In 2002, the tents were completely cleaned of all remaining L. quadriguttatus and dismantled.
Field Results:	Most adults were observed in the field when the burrs had started ripening and changed from green to reddish-purple. Because there is a similar native flea beetle present, with identical feeding evidence, adults need to be identified to confirm establishment. In recent years, sites once heavily populated with L. quadriguttatus adults, have not shown the same results.
Notes:	Native flea beetles are smaller and lack red spots on wing covers. In Hungary and Serbia, L. quadriguttatus exists on the same sites as Mogulones cruciger, both prefer to feed on different parts of the root.

	Pelochrista medullana (Stgr.)
Attacks:	Spotted knapweed, Diffuse knapweed
Agent Type:	Root feeding moth
Origin:	P. medulana released in BC originated in Austria.
Adult:	Adult moths are grey and mottled-brown, small, 14-21mm long, and closely resemble the knapweed flower bracts. Males and females emerge together at a near even ratio from mid-June to the end of July and peak during mid-July (in BC adults continue to emerge in August). They mate within 24 hours, usually at dusk when daily temperatures are 18-30°C. Oviposition begins two to three days after mating and lasts for about 10 days. Females lay eggs singly, or in clusters up to three, onto leaves - preferring rosettes. When temperatures are optimal, the females will lay 42-120 eggs each. The number of eggs laid declines to 10 each during cool, wet weather. The females die one day after they complete oviposition. In the lab, males lived 12.4 days, and females survived only one day longer.
Egg:	The oval, somewhat flattened, 0.03 x 0.35mm, eggs have a strong outer shell with distinct ribs. The white eggs gradually turn to dark yellow during incubation. When the temperature is constantly at 35°C, they hatch in 7-9 days.
Larva/Pupa:	The segmented larvae are whitish-yellow with brown head capsules. New larvae move from the leaf into the rosette centre and mine towards the root crown. Larvae develop through six instars and head capsule measurements are used to define each. The first moult occurs in eight days. The next three instars develop in 3-4 weeks. The final instar is present 6-8 weeks after hatching. Normally, two larvae develop within a root, but up to four can be present on exceptionally large roots. Larvae that feed on flowering plants roots are poorly developed. Webbed tubes are produced along feeding tracks which may be irregular, downward or spiralling. Larvae overwinter and resume feeding for a brief time the following spring before they pupate. Pupation occurs within the webbing inside the root the following spring.
Overwintering:	Immature larvae overwinter in roots and resume feeding the following spring.
Location & Efficacy:	Larvae feeding damage on a root is identical to Agapeta zoegana feeding. It feeds on the outer layers of the root, reducing the plants ability to store nutrients and make the plant more susceptible to infection. Plants which survive the first year of attack go on to produce a smaller number of flowerheads the following year.
Habitat:	Pelochrista medullana is best suited for the dry to moist sites within the diffuse knapweed range. It prefers high density diffuse knapweed. Plants growing in poor, coarse or gravel soils are ideal. P. medullana prefers diffuse knapweed over spotted knapweed. The native geographic range is in eastern Rumania and eastern Austria. It is also expected to be present in south-eastern Russia. In BC, all open field treatments occurs on diffuse knapweed within the Bunchgrass biogeoclimatic zone. The transfers into rearing tents were on diffuse and spotted knapweeds also in the Bunchgrass zone.
History:	In 1982, the first P. medulana field release was made in Pritchard. From 1983 to 1985 two field releases and one caged release was made in Summerland. The existence of P. medullana in BC is unknown, but field monitoring is still ongoing.
Propagation Results:	Egg, larvae, and adult transfers were made into rearing tents (intermittently from 1986-1997) in Kamloops where a small population survived for a couple of years. After several years of not seeing any further adults, the rearing plots were dismantled.
Field Results:	P. medullana larvae and their feeding damage is identical to the wide spread A. zoegana, making identification difficult at field sites. Root sampling from release locations resulted in the subsequent emergence of only A. zoegana and Pterolonche inspersa adult moths. While monitoring the earliest release site near Pritchard a diffuse knapweed plant had feeding similar to A. zoegana, but the larva found appeared to have a distinct mark behind its head; different than what is seen on A. zoegana. The larva did not successfully re-enter the root and subsequently perished.
Notes:	The larvae and feeding damage of P. medullana and A. zoegana appear almost identical. As well, P. inspersa larvae may also be confused with P. medullana, but it feeds in a different location on the root.

	Pterolonche inspersa (Strg.)
Attacks:	Spotted knapweed, Diffuse knapweed
Agent Type:	Root feeding moth
Origin:	P. inspersa populations released in BC originated in Hungary and Austria.
Adult:	Adults measure 14-28mm long, are grey-white coloured, exhibiting a silvery sheen on their wings. They have narrow wings spanning 1.9-2.5cm and when at rest the wings are held close to their sides. The larvae create a 'chimney like' tube which the adults use to exit the root from June to early-September while peak emergence occurs in mid-August. Mating begins immediately and 5-9 days later oviposition starts. Egg laying occurs mainly from late afternoon through the night. An average 142 eggs are laid individually or up to six in a cluster on the underside of rosette leaves. Males live 10-12 days while females live 15-18 days. The male/female ratio is 1:1.5.
Egg:	The black oval eggs are 0.039 x 0.025mm with a slight depressed centre. They incubate for 12 days at 24.6°C. It is essential that the weather remain dry during this time to prevent the egg "shell" from firming, which would prevent the larvae from emerging from the eggs.
Larva/Pupa:	Pterolonche inspersa larvae are pearly white, with inflated segments, and have small brown head capsules. New larvae instar mine down the root, feeding on the woody central portion or the soft tissue near the outer edges. They will fight and kill competing larvae until a sustainable number remain. Normally one or two develop on a single root, but as many as four have been observed. Webbing is spun to cover the feeding area, resulting in a tube. By summer, the tube is 2-2.5mm wide and extends 3-5cm above ground to form a "chimney", which provides a downward route for hibernation. During sunny days the larvae often lie in the tube above the soil surface and move downward when they encounter vibrations, their movement within the tube can cause it to "wave". They overwinter in the third instar and resume feeding the following spring. In July of the following year, the mature larvae prepare to pupate. Pupation takes about 15 days within the tube.
Overwintering:	The third instar larvae overwinter in a silken tube in the root.
Location & Efficacy:	Larvae feed on roots, interrupting the vascular flow of nutrients to the plants. Larvae that hatch near the center of the plant root mine into the woody core. Larvae that hatch near the outer area of the crown feed on the cortex and outer root areas. Feeding reduces the plants' ability to store nutrients which decreases the plants' height and flowering ability. Roots become spongy and fragile and easily break apart. Damaged roots attract other predators which move into the roots and provide secondary attack.
Habitat:	P. inspersa thrives in hot, dry sites with low to moderate plant density. It requires an arid environment with a period of drought during summer. Preferred soils are loose compositions of sand or gravel. It does best in the Bunchgrass and Ponderosa Pine biogeoclimatic zones. Sites with aspen, Douglas fir or lodgepole pine indicate a moist environment which is probably less suitable. P. inspersa feeds on both spotted knapweed and diffuse knapweed, favouring the latter. It was originally believed the Canadian climate was too moist for the moth to thrive. Its native geographic range is south and southeast Europe. It occurs in Spain, France, southern Russia, Hungary, Turkey, Romania, Bulgaria, Italy and Yugoslavia. Its occurrence ends abruptly in eastern Europe. It is found in central Hungary, but is scarce in northwest Hungary and Austria. It is notably absent in eastern Romania. Most common establishments occur on diffuse knapweed stands in northern Greece and western Turkey. Populations favour diffuse knapweed stands that become drought stressed from June to late-September. In BC, release sites occur in the Bunchgrass and Interior cedar-hemlock biogeoclimatic zones. It is probable that this agent will persist and disperse itself as required, filling a niche left by Agapeta zoegana, Cyphocleonus achates, Sphenoptera jugoslavica, Larinus spp. and Urophora spp. Recent sampling indicates P. inspersa has moved into a dry warm pocket of the Interior Douglas-fir zone, where larch, lodgepole pine, and Ponderosa pine share habitat on rocky soils. The best habitat for establishment found in BC is in Ponderosa pine and Bunchgrass zones.
History:	The first P. inspersa treatments were made in 1986 near Osoyoos and into rearing plots in Kamloops. The original field treatment was made with seven adults in poor physical condition and during a rainy period. Releases were made elsewhere in the southern interior and successful establishment and dispersal from these have been studied.
Field Results:	Repeat visits to the original release at Osoyoos in predicted favourable habitat showed it did not establish. This failure is presumed to be a result from the poor condition of the adults at the time of release and the weather conditions. However, the subsequent treatments in 1987 and 1991 in Summerland, near Grand Forks and near Kamloops made on diffuse knapweed have established. The single spotted knapweed treatment occurred in Castlegar in 1987 and has also shown establishment in the past. P. inspersa appears to have the ability to establish and disperse on a limited supply of preferred target plants in desired habitats. Significant mining creates cavities similar to S. jugoslavica and C. achates. Plants attacked by P. inspersa appear shorter than normal and may produce a single bolting stalk or multiple weak bolting stalks, with smaller, or no flowers. Since 2001, extensive sampling near Kamloops has shown the moth has dispersed over 20km in 15 years. The main obstacle it faces is widely spaced diffuse knapweed patches. Similar monitoring in Summerland has shown dispersal to be less than that in Kamloops, but the moth faces different obstacles in the Okanagan. It encounters the same widely spaced diffuse knapweed patches within ongoing development which is removing its preferred habitat. As well, the possibility of insecticide drift from orchards and commercial gardens may limit its population. P. inspersa has crossed major bodies of water from these two original release sites. Spotted knapweed has not been found to be attacked at either Kamloops nor Summerland, even when it was growing next to larvae occupied diffuse knapweed plants. Sampling near Grand Forks and Castlegar was done several years ago, where dispersal was noted, but the distances were not recorded. Recent revisits to some of these areas have shown no establishment on spotted knapweed growing in the Interior cedar-hemlock biogeoclimatic zone. P. inspersa larvae were found on diffuse knapweed growing in prefered habitat.
Notes:	P. inspersa larvae kill and consume larvae and pupae of Sphenoptera jugoslavica, Agapeta zoegana and Pelochrista medullana.

	Subanguina picridis (Kirj.)
Attacks:	Diffuse knapweed, Russian knapweed
Agent Type:	Gall-forming nematode	Previously Known As:	Paranguina picridis
Origin:	The S. picridis populations released in BC originate in Tajikistan, where it existed on Russian knapweed growing in cultivated fields. Today S. picridis has become more widespread and can also be found in central Asia.
Adult:	Nematodes are thin white worms, 1.5mm long and are highly active in water. The first generation nematodes are larger than the second. Males and females are present at the same time in galls, but in variable ratios. The first generation lay eggs for one month, finishing in early-June. The second generation are highly productive and lay eggs from the time the first generation dies until gall desiccation, which is usually in July. Females deposit eggs in clusters inside the galls.
Egg:	Eggs are light yellow, oval shaped and measure 0.05mm long. Eggs from both generations incubate for eight days.
Larva/Pupa:	After hatching, the larvae develop through five stages. First generation juveniles: The first stage is ineffective and leaves the galls with the onset of spring moisture where they congregate in the top 5cm of soil. When the soil temperature reaches 1-4°C and plant shoot growth appears, they move to the pubescent leaf axils. They remain in the bud, feeding on it but not penetrating into it, growing from 0.85mm to 1.0mm long. When temperatures reach 20°C and the plant shoots are 3-5cm tall, 5-55 second-stage juveniles penetrate the plant which develops a gall. The gall becomes visible in three to four days. The young nematodes and galls develop in synchronicity. When the galls reach their maximum size, the nematodes are adults. If males and females occupy the same gall, eggs will be laid for one month. This spring generation lays few eggs, but prepares nutrient rich tissue for the next generation. Second generation juveniles: Eggs hatch and the second generation juveniles feed on the nutritious tissue created by their parents. They mature completely and begin laying eggs near the same time their parents die. This generation will increase the population to 11,500/gall by the end of summer. Second generation eggs hatch and develop to the second juvenile stage. At this time the galls will be drying and the young nematode prepares for winter dormancy. They will become active again with the onset of moist weather, which in ideal situations will occur the following spring when they move into the soil. This generation can vary its development when moist conditions occur. In some instances, fall moisture will activate this generation to enter the soil during fall where they will group in clusters near plant roots. Nematode densities can reach 140 larvae/gram of soil. They are vulnerable to drought at this stage and can be killed in four days if the temperature drops to -12°C. Remaining in the galls or deep in the soil can help prevent expiration. The nematodes may also remain dormant for several years in drought conditions.
Overwintering:	Second stage juveniles desiccate and overwinter in dry galls or deep in the soil to avoid low temperatures. They resume activity when moist weather returns and revives them.
Location & Efficacy:	The nematodes are capable of causing gall formation on leaves and stems on diffuse and Russian knapweed. Galls can be observed within one month following application. In Asian plot studies, 100 grams/m² of gall infected stems killed over 20% of plants and damaged another 30%, greatly reducing flowering.
Habitat:	Subanguina picridis requirements for North America are not known. It has established in areas with moist winters and springs which coincide with its infection period. It requires two months of moist conditions and then a dry fall. Coarse, poor soils on flat or south slopes are ideal. Plants with high nitrogen are not suitable. S. picridis attacks two plant species, but Russian knapweed provides the most nutrition. In the USA, it has established in Colorado, Montana, Oregon, Utah, Washington and Wyoming. Original distribution was once concentrated in Tajikistan and now is widely scattered through central Asia. It is most common on plants growing on south slopes and in poor coarse soils that become dry during the fall drought. In BC, all treatments were made in Bunchgrass, Interior Douglas-fir and Ponderosa pine biogeoclimatic zones. Same year, short-term establishment was found only in the Interior Douglas-fir zone near Kamloops.
History:	S. picridis was first released in BC in 1985. Nematode inoculum was applied to diffuse knapweed research plots in the southern interior in April 1985 and 1986. Same year establishment was maintained for two months and then no further evidence was found. At another study site, S. picridis was applied yearly to Russian knapweed propagation plots from 1986 to 1989. Results of these studies are currently being sought. In 1985 and in 1991 nematodes were applied to a Russian knapweed field sites near Kamloops and in the south Okanagan. The Kamloops location experienced natural fire the same year of the release and the Okanagan site was burned by the owner several years later.
Field Results:	The first two releases were applied to diffuse knapweed in exclosures. Over the next two months, five galls were located from May 31 to June 19. No further evidence was found to confirm establishment. Applications were then made on Russian knapweed in the central Okanagan valley and the Thompson area, but fire complicated the results. It is not known if the bioagent absence was due to the fire in both situations.
Notes:	The second generation is the productive generation that guarantees survival. Their continued existence is dependent on the amount of nutritive tissue made available. Which is produced in greater quantities on Russian knapweed than on diffuse knapweed. S. picridis galls appear to encourage the increase of Puccinia acroptili. The two biocontrol agents co-exist in Saskatechwan.

	Terellia virens (Loew)
Attacks:	Spotted knapweed, Diffuse knapweed
Agent Type:	Seed feeding fly
Origin:	The T. virens populations released in BC originated in Swiss Valais and Austria.
Adult:	Adults are about 5mm long with yellow or greenish bodies. They have clear wings and large bright green eyes. They emerge in late-May, usually about four weeks before the spotted knapweed plants begin to bloom. Mating and oviposition begin with the arrival of warm weather. Adults mate and oviposit for their entire 48 day lifespan. Females lay up to 80 eggs each, which are individually deposited into flowerheads. The females then leave a scent by dragging their ovipositor over the site and on the upper stem leaves to discourage other females from using the same head. Depending on climate and weather, one or two generations will be produced. If there are two generations, both will lay eggs within the same season.
Egg:	The elongated, shiny white, 1.0mm eggs incubate for 3-5 days.
Larva/Pupa:	The new white larvae gradually change to yellow-brown over 14 days and develop into a plump barrel-shape. The first two instars feed within a single ripening seed. As they mature, they move onto other seeds and, in some instances, the tissue below the seeds. If the climate allows for two generations, the first generation will pupate just above the receptacle in an upright cocoon made of loosely woven plant fibres. In instances where there is only one generation, the larvae prepare to overwinter inside the cocoon which is partially inserted into the receptacle. Both generations have yellow-brown pupae. In most cases there will only be one generation.
Overwintering:	Larvae overwinter from either first or second generation adults. Pupation occurs the following spring.
Location & Efficacy:	Larvae feeding in flowerheads cause considerable damage to seeds. It completely consumes some seeds and partially feeds on others. It has been measured to cut viable seed production by 90%.
Habitat:	South facing dry slopes within the dry end of the spotted knapweed range is suitable for Terellia virens. In the USA it has established in Montana and Oregon. Predicted preferred BC habitat will be similar to that found in the Okanagan Valley, Kamloops, Castlegar and Grand Forks. In its native habitat, T. virens occurs on dry sites within the grape growing areas of western, central and south-eastern Europe. It is found in southern Austria, east and central portions of the former Czechoslovakia, southern France, southern Germany, western and central Hungary, Israel, Turkey, Italy, Jordon, Morocco, eastern Romania and south Switzerland. In BC, releases have been made into the Bunchgrass, Interior cedar-hemlock, Interior Douglas-fir and Ponderosa pine biogeoclimatic zones. Short-term establishment was confirmed in the Bunchgrass and Interior cedar hemlock zones.
History:	T. virens was first introduced into rearing plots in 1991 and again in 1995. Field releases occurred in 1991 and 1995 in the southern interior.
Propagation Results:	A small population persisted in the rearing tents for several years but insufficient numbers developed to allow for collection. It was reared and propagated in a competitive environment with Urophora spp. for several years before it was eventually displaced. In 2000 the rearing plots were excavated.
Field Results:	In 1993, T. virens was confirmed established at one site near Kamloops. Subsequent releases in the Kootenays had shown limited establishment, though recent observations have not indicated long term success. Monitoring has indicated the possibility that low populations may exist in two areas of the southern interior. In 2008, field monitoring was done at sites that were previously established. None of the sites confirmed continued establishment.
Notes:	T. virens may be a possible biocontrol agent for black knapweed. It is a weak competitor against Larinus minutus. It can inhabit sites with Chaetorellia acrolophi and Urophora species. However, high densities of U. affinis may interfere with T. virens opulations.

	Trichosirocalus horridus
Attacks:	Bull thistle, Marsh plume thistle, Nodding thistle, Plumeless thistle
Agent Type:	Rosette/root crown feeding beetle (weevil)
Origin:	The T. horridus populations released in BC originated in Germany.
Adult:	The oval, rounded, grey-brown mottled weevils are 3.5-4.5mm long. Their shape is very similar to Mogulones cruciger and has visible hairs protruding from their body. They have a long rostrum (nose) that is 3-4mm long. When disturbed and handled, they emit high pitched shrieks which can be heard when the weevil is held near your ear. Adults emerge from plants in April, and linger until the end of June or early-July. They hibernate through the warm summer months then reappear in September. Spring adults are usually present up to the end of Balsamroot flowering. Their spring presence is first made obvious by their circular feeding holes on rosettes while they congregate under leaves. They camouflage on the soil and are difficult to see. On bolting plants the adults hide in leaf axils and between floral bracts. When disturbed or frightened, they drop and roll into a ball, tucking in their heads and closely resembling soil particles. Mating and ovipositing occurs in the spring and the fall. Females lay about 800 eggs (maximum 2000) during their life span. Females chew holes in the leaf mid-veins on large rosettes and oviposit eggs individually or in clusters up to ten. Eggs may also be laid on the underside of leaf surfaces. Adults disperse easily, seeking scattered plants over large areas.
Egg:	Eggs are yellow-white coloured and measure 0.54 x 0.33mm. During incubation the eggs become deeper yellow with brown dots which indicate developing larvae head capsules. Temperature varies the incubation period from 5-30 days. Most hatching will occur in 10-12 days.
Larva/Pupa:	Larvae are white and slender with brown head capsules. There are three instars. Larvae that hatch from eggs laid in the vein will move through the vein and downward towards the crown. Larvae that hatch from eggs laid on leaf surfaces will move across the leaf and bore into the crown. Once they are inside the crown, they feed in tissue below the terminal bud. At 20°C, all three instars will complete development in 6-12 weeks (longer in cooler weather). Mature larvae leave the root and enter the soil to pupate. They create a cell chamber made from silk and soil particles. The pupae are about 4.3mm long. Pupation takes 14-25 days.
Overwintering:	Trichosirocalus horridus can over winter in all stages as eggs, larvae, pupae or adults. The earliest summer generation adults to emerge may breed into September and produce a second generation which can overwinter as eggs, larvae or pupae.
Location & Efficacy:	Larvae mine the crown of rosettes and within bolted stems. Attacked buds fail to grow and when leaves are pulled back they will expose the blackened mined cavity and several larvae may be exposed. Attacked plants can develop multiple stems, which tend to be shorter and produce weaker flowers. Larvae that develop in leaf axils on bolted stems also produce decaying black cavities. Weak plants can die from attack. Adults feeding in high amounts contribute to reduced plant vigour. Some sites in the USA have been reported to have nodding thistle sites disappear in 5-6 years and plumeless thistle sites disappear in 10-12 years. There are reports that T. horridus dispersal increased from 600 km² to 4,300 km² in four years.
Habitat:	T. horridus is suitable on sites which have long, cool springs. They appear to favour areas on the fringes of forest openings and where host plants grow somewhat shorter than normal. They require dense thistle stands and large rosettes. In Canada it is established in BC, Alberta, Saskatchewan, and Manitoba. Its native European distribution is from the Mediterranean to Russia where it occurs from sea level to 1,800 m. In BC, T. horridus releases have been made in the Bunchgrass, Coastal western hemlock, Interior cedar-hemlock, Interior Douglas-fir, Ponderosa pine and Sub-boreal spruce biogeoclimatic zones. Establishment has been confirmed in the Bunchgrass, Interior cedar hemlock, Interior Douglas-fir and Ponderosa pine zones.
History:	In 1979, the first T. horridus release was made on nodding thistle west of Williams Lake along Highway 20. No further releases were made until 1986-1988, and 1991, when the weevil was once again introduced to nodding and plumeless thistle infestations. In 2005, weevils were collected from rearing plots for redistribution. In 2007 and 2008 adult weevils were tried on Marsh plume thistle and Scotch thistle infestations.
Propagation Results:	In 2003 there appeared to be an increase of plumeless thistle and a resurgence of nodding thistle in the southern interior. T. horridus was established in propagation tents in 2003 to rear collectable populations for redistribution. The rearing plots were established with 29 adults and one larvae infested root. From these few parents, 1,499 adults were collected for field release in 2005. The rearing tents are still maintained and the collections are now tried on two other thistles (Scotch and marsh plume) that the weevil may also attack. In the tents, a small population appears in mid- to late-April and a second, larger flush arrives throughout June, which reduces through July, and reappears in September.
Field Results:	The earliest release in the Chilcotin was presumed not to have establish after excavation disrupted the site a short time after the release. In 2002, T. horridus was located at a historical release site near Princeton. This sighting renewed the need to reinvestigate other T. horridus releases in BC, including the sites west of Williams Lake. Despite the excavation, the weevil was present in 2003 and had dispersed among the widely spaced small patches and on isolated individual plants. Some plants were stunted, as short as 20cm, but still trying to flower. All of the 2005 release sites had established by the following year, with adults present at all but one. In the field, adults and larvae are present in April and May. Adults and their feeding can be seen on rosettes. As well, the larvae and their central rosette damage can also be observed during this time. Ovipositing occurs not only on rosettes, but also on small bolting stems. By the time larvae damage is visible, the bolting stems may be 50cm high and when the leaves are pulled away the larvae can be observed. Adults appear to be more vocal during April and June than in the fall. Adults also appear to emerge later when released onto plumeless thistle than on nodding thistle. It is not known if this is a result of the weevils having to adapt to a different host plant species than the one from which they were collected (nodding thistle) or if it is linked to plant phenology. There have been no releases made on bull thistle, but a recent release was made onto a site where both nodding and bull thistles occur. The intent is to determine if T. horridus will actually transfer from nodding thistle as the literature suggests.
Notes:	T. horridus shares most of its sites and host plants with Rhinocyllus conicus and Larinus planus.

	Tyria jacobaeae (Linnaeus)
Attacks:	Tansy ragwort
Agent Type:	Foliar feeding moth
Origin:	The T. jacobaeae populations released in BC originated in Switzerland.
Adult:	Adults are attractive bright red and brown/black moths with a wingspan of 35-45mm, and when at rest the wings are held in a triangular "tent-like" formation. Forewings are black with brilliant crimson red stripes on the upper and lower margins and have two red dots near the tips. Adults emerge in late-spring (May through June). Mating and egg laying begins within a few days. Females each lay 73-285 eggs, laid in batches of 10-150 onto the underside of rosette basal leaves. The adults are highly active and take to flight when approached. They are attracted to light and peak flights occur at dawn and dusk. When populations are high, the moth migrates in mass flights. The brilliant colouring indicates the possibility of toxicity, therefore discourages predators.
Egg:	The eggs are 1mm round with ribs. Initially yellow, they gradually turn transparent grey and hatch after several weeks.
Larva/Pupa:	There are five larval instars. The larvae colour changes from the initial first instar grey-green to yellow and black (second through fifth instars). When mature, they will measure 2.5cm long. The first instar feeds aggressively on the undersides of the leaves before they make their way to adjacent leaves and bolting stems. When disturbed, young larvae drop and are suspended by a silken thread. When safe to do so, they climb up the thread and return to feeding. They prefer to feed on flowers and those that do go on to produce larger adults that lay more eggs. Leaves and tender stem parts are less preferred, but will also be heavily consumed in large colonies. The larvae have been known to travel up to 800m to seek food sources when the plant densities decrease. Larvae must consume sufficient plant material to pupate and need to be at least 140mg to fully develop (some will grow larger, up to 260 mg). Feeding on tansy ragwort causes the larvae to store toxins which discourage bird or rodent predation. They are prone to nosema, virus diseases and predation by some ants and beetles. Mature larvae leave the plant and prepare to pupate. Dark brown pupae develop under stones and debris near the plants. Dry locations will cause the larvae to dehydrate and lose body weight. They can lose up to 1/3 of their mass before they will die. Too much moisture is equally detrimental to the larvae/pupae which will absorb the moisture.
Overwintering:	Pupae overwinter under rocks, debris and in soil near the plant community.
Location & Efficacy:	Larvae are aggressive feeders, capable of completely defoliating plants. In colder climates, defoliated plants may die in winter conditions. Defoliation reduces plant density and seed production.
Habitat:	Tyria jacobaeae does well in open, sunny, warm sites below 1,000m and west of the Cascade Mountains. Population continuance depends on plant density. Plants are required to have a density of at least 4/m2. It does poorly in shaded areas, under canopy, in steep canyons or on low density plants. Sites adjacent to coastal elements or areas that flood do not establish well. Conversely, sites that have prolonged dry periods, especially during the moth's pupation period, are undesirable. Sites with high ant populations should be avoided. It is native from Europe to west central Asia. In the Netherlands it occurs in sandy dune areas. In BC, T. jacobaeae has been released, and established, into the Coastal Douglas-fir and Coastal western hemlock biogeoclimatic zones. It has failed to establish in the Interior Douglas-fir zone. T. jacobaeae requires thick patches of plants for the larvae to feed on.
History:	In 1962, T. jacobaeae was first released near Abbotsford. Collections from established field sites began in the 1970s and continued at regular intervals through to the 1990s. Assisted redistribution has recently occurred to move the moth onto Texada Island and a second attempt to establish the moth in the Okanagan was made in 2008.
Field Results:	T. jacobaeae can be found dispersed throughout the Fraser Valley and coast islands, including Vancouver Island. Sightings in the coastal community are limited to where the invasive plants grow in dense patches which can support the aggressive feeding larvae. The moth (aka: cinnabar moth) became so abundant near Nanaimo that the area was later named 'Cinnabar Valley'. In the Fraser Valley, adults have been seen in mid-May and evidence of larvae feeding has been found in August. Larvae are found on Vancouver Island during July. It is too early to determine if the latest attempt to move the agent into the interior was successful.
Notes:	The moths are difficult to find in large numbers after plants decrease. When toxic alkaloids are consumed from host plants they accumulate. The larvae and adults are usually avoided by birds and rodents, (red, orange, yellow and black colours warn potential predators). Releasing with Longitarsus jacobaeae adds to excellent control.

	Urophora solstitialis (L.)
Attacks:	Nodding thistle, Plumeless thistle
Agent Type:	Seed feeding fly
Origin:	The U. solstitialis released in BC originated in Steinfeld, Austria where it occurs on nodding thistle.
Adult:	The flies are 5-8mm long, have black bodies with light brownish-yellow thoraxes and yellow heads and legs. They have 3.1-4.5mm long clear wings with slender dark bands forming two "V's". Females can be identified by their long, pointed ovipositor. Adults emerge over six weeks beginning in late-spring to early-summer, which coincides with the flower bud stage. Mating begins immediately and oviposition starts within 1-2 days. Adults live for several weeks and are present for most the summer, enabling them to oviposit into early and late buds. Females oviposit an average of 100 eggs which are deposited individually, but may also oviposit several times into the same bud.
Egg:	Eggs develop over three days. Specific details about egg size, shape and colour are not known.
Larva/Pupa:	Larvae are creamy white, barrel-shaped with black posteriors. When mature, they are 3-4mm long. Newly hatched larvae mine florets inducing the plant to create gall formations around each of the larvae. The first moult occurs before they reach the receptacle. They continue to feed through their second instar inside the seedheads as the galls begin to form. They moult again and the third instars feed on gall tissue that has formed. In time, the gall hardens and becomes woody. Multiple larvae cause the galls to fuse together to form a large mass. Mature larvae prepare for pupation inside the cells. The larvae that complete development prior to the end of June will emerge as second generation and will mate and oviposit, but most larvae will overwinter and pupate the following spring.
Overwintering:	Usually Urophora solstitialis will overwinter as first generation mature larvae in gall cells or as second generation larvae.
Location & Efficacy:	Gall formation exhausts plant nutrient reserves and reduces overall plant vigour. The main control of the target plants is achieved by larvae feeding in flower buds, thereby reducing seed production. A maximum of 10 larvae can be present in each seedhead, where each is responsible for reducing five seeds. Studies indicate seeds are reduced in 30% of all plants and reductions have been recorded up to 81% in individual heads. In Ontario, larvae attacking seedheads reduced seed production by 17% in three years.
Habitat:	Specific U. solstitialis habitat requirements are unknown. In Canada, it has established in Ontario. The fly occurs throughout Europe and North Africa.
History:	A single U. solstitialis release was made in 1991 into the central lower Kootenays on a mixed stand of plumeless and nodding thistles. No establishment has been found and monitoring is still ongoing.
Field Results:	The single release site has been revisited many times since the release was made. No flies where ever found. The site has been repeatedly sprayed with herbicide, but it is not known if this has affected establishment.
Notes:	U. solstitialis and U. jaceae are commonly misidentified. U. solstitialis can co-exist with Rhinocyllus conicus and Trichosirocalus horridus on nodding and plumeless thistles, but R. conicus may slowly be displaced in stands of plumeless alone.