Bug FAQYellow Starthistle Flower Weevil
Larinus curtus · Order: Coleoptera · Family: Curculionidae
Also called: Weevil
The yellow starthistle flower weevil is about 6 mm long and dark brown or black with light mottled hairs. It lives at low densities across the Pacific Northwest and is used to control the invasive weed yellow starthistle. Native to southern Europe and the Mediterranean, the adult feeds on flowers and pollen while the larva eats developing seeds inside the flower head.
Source: Wikipedia
Size
They measure about 6 mm (¼ in) in length.
Source: Wikipedia
How to get rid of it
The weevil is released as a biological control agent against the invasive weed yellow starthistle in the United States.
Source: Wikipedia
Where it lives
The species is now established throughout the Pacific Northwest, though usually at low densities.
Source: Wikipedia
What it eats
Adult weevils feed on yellow starthistle flowers and pollen, causing little plant damage. Larvae hatch inside the flower head and consume the developing seeds.
Source: Wikipedia
Life cycle
Females lay glossy, milky-white oval eggs at the base of open yellow starthistle flowers. Eggs hatch in a few days, and the larvae move into the flower head to feed on seeds.
Source: Wikipedia
Where it comes from
It also originates from the broader Mediterranean region.
Source: Wikipedia
Where it is found in the US
Recorded in 5 of 51 states and DC. Most records: California, Oregon, Washington, Idaho, Utah.
Darker = more records. Counts are museum and citizen-science records, not population size.
Source: GBIF
Months it is reported in the US
Source: GBIF
More photos
Questions people ask
What does the yellow starthistle flower weevil eat?
Adults feed on the flowers and pollen of yellow starthistle, while the larvae eat the developing seeds inside the flower head.
Source: Wikipedia
How is this weevil used for weed control?
It is released as a biological control agent to reduce populations of the invasive yellow starthistle weed in the United States.
Source: Wikipedia
Same family (Curculionidae)
Green Immigrant Leaf WeevilPolydrusus formosusDamages trees, gardens or crops
Black Vine WeevilOtiorhynchus sulcatusDamages trees, gardens or crops
Nettle weevilPhyllobius pomaceusDamages trees, gardens or crops
Asian Oak WeevilCyrtepistomus castaneusDamages trees, gardens or crops
Strawberry Root WeevilOtiorhynchus ovatusDamages trees, gardens or crops
Common Leaf WeevilPhyllobius pyriDamages trees, gardens or cropsSources
- Wikipedia: https://en.wikipedia.org/wiki/Larinus_curtus
Look it up elsewhere: GBIF · iNaturalist · BugGuide · Wikipedia
Text written 2026-10-26 from the sources above and checked sentence by sentence against them. Data fetched 2026-10-26.