Plain Wave
Idaea straminata

Idaea straminata, the plain wave, is a moth of the family Geometridae. It is found in Europe including West Russia and Balkans. Source
Where it is now
In the last 8 weeks this insect was recorded 24 times across 4 areas (each area is a 5 degree square).
See the Plain Wave on the live map
Movement and weather
Each season it is first heard regularly where daytime highs are around 21°C (typically 21 to 23°C, from 6 areas). That holds across 20° of latitude, which suggests its timing follows temperature more than the calendar.
Over the weeks it was present in the past year, its centre in Europe ranged from 47°N in September to 61°N in July, about 1,500 km apart.
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 | 18 May 2026 | 6 July 2026 | 27 July 2026 | 6 |
Figures are effort corrected and come from automatic sound identification, which makes mistakes. How this is measured and how it compares with human observers.