Chestnut Gall Wasp
Dryocosmus kuriphilus

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, including most cultivated varieties. It is considered the world's worst pest of chestnuts. Source
Where it is now
In the last 8 weeks this insect was recorded 18 times across 2 areas (each area is a 5 degree square).
See the Chestnut Gall Wasp on the live map
Arrival dates
The week it was first heard regularly in each region, after at least six weeks away. Dates differ from south to north, so a region has a range.
| Region | First arrival | Last arrival | Typical peak | Areas |
|---|---|---|---|---|
| Europe | 4 May 2026 | 4 May 2026 | 17 August 2026 | 1 |
Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.