Larinus curtus
In 3 days ~10% in a week ~20%
Larinus curtus is a species of true weevil known as the yellow starthistle flower weevil. It is native to Southern Italy, Southern Europe, the Middle East and the Caucasus. It is used as an agent of biological pest control against the noxious weed yellow starthistle (Centaurea solstitialis) in the United States.
The adult weevil is dark brown or black with light colored mottled hairs on its body. It is about 6 millimetres (1⁄4 in) long. The female lays glossy, milky white, oval-shaped eggs at the bases of open yellow starthistle flowers. The larva emerges from its egg in a few days and goes inside the flower head, where it feeds on the developing seeds. A larva is capable of destroying all of the seeds inside a given head, with an average reduction of 96%. The adult feeds on flowers and pollen but probably does little damage to the plant. It is the larva's impact on seed production that helps control the plant's spread.
There have been field reports of large numbers of adult L. curtis feeding on safflower flowers Carthamus tinctorius, but no evidence that larvae have successfully developed on this plant. This weevil is native to southern Europe and the Mediterranean. It was first introduced to the United States as a biocontrol agent in 1992. It is now established throughout the Pacific Northwest, but in relatively low densities. Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Sacramento | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report a Yellow Starthistle Flower Weevil sighting in Sacramento on a given day, based on 10 verified sightings from GBIF citizen-science data. It is the 238th most-seen of the 386 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 20%, if each day is a fresh chance.
May and June
In those months about 10% of wildlife watchers report a Yellow Starthistle Flower Weevil in Sacramento on a given day, against under 5% in July to April, the lowest months. Those are among Sacramento's driest months, with about 15 mm of rain a month against 120 mm in December.
Only Sacramento, in our data
Sacramento is the only city on Wallace's Line with enough records to rate Yellow Starthistle Flower Weevil sightings: under 5% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Yellow Starthistle Flower Weevil is recorded against all the insects logged in Sacramento (10 verified sightings), calibrated against known sighting rates. Figures are rounded to the nearest 10% because citizen-science data supports honest approximations, not decimals, and months with records from fewer than five people show "—". How it works.
