| DESCRIPTION: Beetle- N/A | |||||||
| BACKGROUND | LIFE CYCLE | ||||||
| Availability | Habitat | Adult Emergence | Egg Laying | Larva Development | F1 | Adult Life Span | Over Winters |
| P | Canada thistle sites | June to September | Leaves and stems | Develop on foliage and pupate in soil | 40 days | Adults | |
| ATTACK | COLLECTION | NOTES | |||||
| Stage | Damage | Life Stage | Method | ||||
| Larvae and adults | Foliage | Adults June to September | Hand pick | ||||
| DESCRIPTION: Weevil - 2 to 3 mm mottled-grey color with white cross marking on back | |||||||
| BACKGROUND | LIFE CYCLE | ||||||
| Availability | Habitat | Adult Emergence | Egg Laying | Larva Development | F1 | Adult Life Span | Over Winters |
| N | Dense stands 5 to 10 plants/m2 surrounded by bare soil |
Coincides with rosette stage | May to June eggs laid in mid vein of leaf | Mine down stem to root collar | Late June to early July | 10 months | Adult in leaf litter |
| ATTACK | COLLECTION | NOTES | |||||
| Stage | Damage | Life Stage | Method | Adults can withstand some spring flooding | |||
| Larvae - | Stem and root miner | Adults on warm sunny August days | Sweep net, aspirator | ||||
| DESCRIPTION: Weevil - 5 to 10mm dark brown body | |||||||
| BACKGROUND | LIFE CYCLE | ||||||
| Availability | Habitat | Adult Emergence | Egg Laying | Larva Development | F1 | Adult Life Span | Over Winters |
| G | Adaptable to varying habitats of Canada thistle | Mid June | Early July in unopeneed flower buds < 7mm diameter | In flower head | Late August to September | 10 months | Adult in plant litter |
| ATTACK | COLLECTION | NOTES | |||||
| Stage | Damage | Life Stage | Method | ||||
| Larvae - | Flower head | Adults early summer | Sweep net, aspirator | ||||
| DESCRIPTION: Fly - 5 to 6mm black body clear wings marked with 'W' | |||||||
| BACKGROUND | LIFE CYCLE | ||||||
| Availability | Habitat | Adult Emergence | Egg Laying | Larva Development | F1 | Adult Life Span | Over Winters |
| N | Moist to wet low elevation sites near rivers/lakes with partial shade | May to July | May to July into tips of new shoots | In stem galls | Not known | Larvae in galls in stems | |
| ATTACK | COLLECTION | NOTES | |||||
| Stage | Damage | Life Stage | Method | Release where stands are 50 to 100 cm tall. | |||
| Larvae - | Stem | Larvae in galls late summer to freeze up | Collect stems | ||||