Dryocosmus kuriphilus
In 3 days ~10% in a week ~30%
Dryocosmus kuriphilus is a species of gall wasp known by the common names chestnut gall wasp, Oriental chestnut gall wasp, and Asian chestnut gall wasp. It is native to China and it is known in many other parts of the world, particularly the Northern Hemisphere, as an introduced species and an invasive horticultural pest. It attacks many species of chestnut (genus Castanea), including most cultivated varieties. It is considered the world's worst pest of chestnuts.
When it was first discovered, the wasp was considered to be a species of Biorhiza. It was given its current name in 1951, when it was formally described. By this time it had invaded Japan and was attacking chestnuts there. It is now in Korea, Nepal, Italy, Slovenia, France, Switzerland and other parts of Europe including Flanders, Belgium, and the southeastern United States.
The adult female wasp is 2.5 to 3 millimeters long and shiny black in color with brown legs. It produces stalked white eggs, each about 0.2 millimeters long, and the larva is white and about 2.5 millimeters long. The adult male of the species has never been observed.
The female lays eggs in the buds of... Wikipedia →
| # | Park | Country | Daily sighting probability |
|---|---|---|---|
| 1 | Cévennes National Park | 🇫🇷 France |
More parks will be added in future updates.
| # | City | Country | Daily sighting probability |
|---|---|---|---|
| 1 | London | 🇬🇧 United Kingdom | |
| 2 | Vienna | 🇦🇹 Austria | |
| 3 | Paris | 🇫🇷 France | |
| 4 | Berlin | 🇩🇪 Germany | |
| 5 | Washington | 🇺🇸 United States |
Rare
Under 5% of wildlife watchers report an Asian Chestnut Gall Wasp sighting in Cévennes National Park on a given day, based on 7 verified sightings from GBIF citizen-science data from 2019 to 2026. It is the 730th most-seen of the 996 insects we can rate there. Over three days the chance rises to about 10%, and over a week to about 30%, if each day is a fresh chance.
February, May–June and October
In those months about 10% of wildlife watchers report an Asian Chestnut Gall Wasp in Cévennes National Park on a given day, against under 5% in March–April, July–September and November–January, the lowest months.
Between 9 am and noon
Across all the parks we cover, that three-hour window holds the most Asian Chestnut Gall Wasp sightings with a recorded time, and nearly all of them come between 6 am and 6 pm: it is a daytime animal.
Only Cévennes National Park, in our data
Cévennes National Park is the only park on Wallace's Line with enough records to rate Asian Chestnut Gall Wasp sightings: under 5% of wildlife watchers there report one on a given day.
GBIF citizen-science records
It is estimated from how often the Asian Chestnut Gall Wasp is recorded against all the insects logged in Cévennes National Park (7 verified sightings from 2019 to 2026), 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.
