| DESCRIPTION: Beetle - 3 to 7 mm dark brown oval shaped | ||||||||
| BACKGROUND | LIFE CYCLE | |||||||
| Availability | Habitat | Adult Emergence | Egg Laying | Larva Development | F1 | Adult Life Span | Over Winters | |
| G | Plumeless thistle range | Spring | Early summer on underside of flower bud | Bore into flower buds | Mid summer | Up to 15 months | Adult in leaf litter | |
| ATTACK | COLLECTION | NOTES | ||||||
| Stage | Damage | Life Stage | Method | F1 that emerge while days are more than 16 hours complete a second generation. | ||||
| Larvae - | Seed head | Pupa prior to adult emergence | Clip seed head | |||||
| Adults - | Leaves | Adult | Hand pick | |||||
| DESCRIPTION: Weevil - 3 to 4 mm brown spherical shaped | |||||||
| BACKGROUND | LIFE CYCLE | ||||||
| Availability | Habitat | Adult Emergence | Egg Laying | Larva Development | F1 | Adult Life Span | Over Winters |
| G | Dense stands of plumeless thistle | Early spring | Early spring on vegetative buds | Mine into and feed on vegetative buds | 10 months | Adults under rosettes | |
| ATTACK | COLLECTION | NOTES | |||||
| Stage | Damage | Life Stage | Method | Most effective in areas with long, cool springs. | |||
| Larvae - | Seed head | Adults mid to late summer | Tray during flowering | ||||
| Adults - | Leaves | ||||||
| DESCRIPTION: Fly - 4.5 mm black body, distinctive pattern on wings | |||||||
| BACKGROUND | LIFE CYCLE | ||||||
| Availability | Habitat | Adult Emergence | Egg Laying | Larva Development | F1 | Adult Life Span | Over Winters |
| N | Exact preference not yet determined | Late spring to early summer | June or July singly laid in floret tubes | In flower head receptacle | Late summer | 3 weeks | Larvae in galled seed heads |
| ATTACK | COLLECTION | NOTES | |||||
| Stage | Damage | Life Stage | Method | Spring collection must be completed before fly emergence. | |||
| Larvae - | Seed head | Larvae in gall in fall or early spring | Clip galled flower heads in the fall or early spring | ||||