Green Thistle Beetle
Cassida rubiginosa

The thistle tortoise beetle is a species of beetle in the subfamily Cassidinae and the genus Cassida. The thistle tortoise beetle can be recognized by its green, rounded back and it can be found on thistle plants in many regions of North America and Europe. The thistle tortoise beetle was first discovered in 1902 in Lévis, Quebec. In 1931, Nellie F. Paterson was the first to document the mature larva. Later, the instar larva of this species was first recorded in 2004 by Jolanta Świętojańska. The thistle tortoise beetle exhibits multiple defense behaviors, such as a flexible shield, providing a barrier against the mandibles of predators, and an excretion that protects the eggs as well. Source
Where it is now
No records in the last 8 weeks. It may be out of season where the observers and sensors are.
See the Green Thistle Beetle 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 | 6 April 2026 | 6 April 2026 | 4 May 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.