Crotch's Bumblebee vs Black Headed Birch Sawfly
Side-by-side species comparison
| Attribute | Crotch's Bumblebee | Black Headed Birch Sawfly |
|---|---|---|
| Scientific Name | Bombus crotchii | Craesus alniastri |
| Order | Hymenoptera | Hymenoptera |
| Family | Apidae | Tenthredinidae |
| Size | 10-16 mm | 7-9 mm |
| Habitat | Heathland | Woodlands |
| Diet | Nectar Feeders | Herbivores |
| Regions | California, western USA | Europe |
| Conservation | Endangered | Least Concern |
Crotch's Bumblebee
A western North American bumblebee that has declined by over 90% from its historical range. Once common in California's Central Valley. Threatened by pesticides and habitat loss.
Did You Know?
Has vanished from most of California's agricultural Central Valley where it was once the dominant bumblebee.
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.