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:  Bruchidius villosus adults and seeds 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:  Bruchidius villosus feeding in seed pods 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.