Cimbicid
Guides
Cimbex
Elm sawflies, Birch sawflies, Almond leaf wasps
Cimbex is a genus of large, robust sawflies in the family Cimbicidae, distributed across North America, Europe, and Asia. Adults are among the largest sawflies, with body lengths reaching 20-25 mm, and are frequently mistaken for bees or wasps due to their plump appearance and yellow-and-black coloration. The genus includes notable species such as C. americanus (elm sawfly), C. femoratus (birch sawfly), and C. quadrimaculatus (almond leaf wasp), some of which are significant defoliators of trees. Larvae are caterpillar-like, with seven pairs of prolegs distinguishing them from lepidopteran caterpillars, and possess chemical defense glands. The genus has a fossil record extending from the Eocene to the Miocene.
Cimbex americanus
elm sawfly, North American Elm Sawfly
Cimbex americanus, commonly known as the elm sawfly, is a large, non-stinging sawfly in the family Cimbicidae. Adults measure approximately 20–30 mm in body length and are among the largest sawflies in North America. The species exhibits sexual dimorphism in coloration: males have yellow-orange abdomens, while females display black abdomens with yellow transverse bands. Larvae feed on foliage of various broadleaf trees, particularly elm and willow, and can reach 50 mm in length. The species has a single generation per year, with larvae overwintering in soil cocoons before pupating in spring.
Cimbex rubidus
Rusty Willow Sawfly
Cimbex rubidus, commonly known as the Rusty Willow Sawfly, is a large sawfly in the family Cimbicidae. Adults are robust, wasp-like insects with clubbed antennae characteristic of the family. Larvae feed on willow foliage and have a caterpillar-like appearance with seven pairs of prolegs, distinguishing them from lepidopteran caterpillars which have five or fewer pairs. The species is closely related to the Elm Sawfly (Cimbex americana) and shares many biological traits with other members of the genus.