About Cimbex femoratus (Linnaeus, 1758)
Cimbex femoratus (Linnaeus, 1758) adults reach a body length of 17–23 millimetres, or 0.67–0.91 inches. They have a large head with large, strong mandibles. Their wings are smoky brown with brown margins. The thorax is shiny black, while the shiny black abdomen has a whitish band and a large red-brown band, a trait that is especially prominent in males. The antennae are black at the base and yellow-orange at the tip. The last segments of the legs are also yellowish. Adult Cimbex femoratus fly from May to August. Larvae of this species are pale bluish-green, reaching approximately 45 mm in length, and closely resemble caterpillars. Most larvae have a dark, narrow bluish longitudinal stripe along their back. Larvae can be found between June and September, and feed exclusively on the leaves of birch trees (Betula sp.). This sawfly species is widespread across Europe and Siberia, and can also be found in Canada. These sawflies prefer habitats where birch trees grow.
