Alder Leaf Beetle vs Black Headed Birch Sawfly
Side-by-side species comparison
| Attribute | Alder Leaf Beetle | Black Headed Birch Sawfly |
|---|---|---|
| Scientific Name | Agelastica alni | Craesus alniastri |
| Order | Coleoptera | Hymenoptera |
| Family | Chrysomelidae | Tenthredinidae |
| Size | 6-7 mm | 7-9 mm |
| Habitat | Ponds & Lakes | Woodlands |
| Diet | Herbivores | Herbivores |
| Regions | Europe, Western Asia | Europe |
| Conservation | Least Concern | Least Concern |
Alder Leaf Beetle
A metallic dark violet-blue beetle that feeds on alder trees. Heavy infestations can completely defoliate alder trees along waterways.
Did You Know?
After being absent from Britain for decades, it dramatically recolonised southern England in the early 2000s.
Black Headed Birch Sawfly
A medium-sized sawfly with a dark head and orange body. Larvae are greenish-blue with black heads and feed communally on birch and alder leaves.
Did You Know?
When a predator approaches, the entire colony of larvae simultaneously rears up and thrashes, making the group appear larger and more threatening.