Cephidae

Definition

A family of stem sawflies (suborder Symphyta, superfamily Cephoidea, order Hymenoptera) characterized by a cylindrical, nearly parallel-sided body, reduced wing venation with few crossveins, and larvae that bore into the stems of grasses and sedges. The family comprises approximately 27 genera and more than 160 described species, distributed across four subfamilies: Athetocephinae, Australcephinae, Cephinae, and Cuspilonginae. Unlike most sawflies, cephids lack a saw-like ovipositor and possess a more wasp-waisted appearance, though they are phylogenetically basal within Hymenoptera.

Etymology

From the type genus Cephus (Greek kephē, 'head' or 'chief', possibly referring to head structure) + Latin -idae (family suffix).

Example

The wheat stem sawfly Cephus cinctus (family Cephidae) is a significant agricultural pest in North American cereal crops, with larvae tunneling through wheat stems and causing lodging; its narrow, elongate body distinguishes it from the broader, more robust sawflies of families such as Tenthredinidae.

Synonyms

• cephids

Related Terms

• Symphyta
• Hymenoptera
• Cephoidea
• sawfly
• stem borer
• Cephus
• Calameuta
• Tenthredinidae
• Parasitoid
• agricultural entomology

Usage Notes

Cephidae is one of the smaller sawfly families and is distinguished from the more diverse Tenthredinidae (common sawflies) by body form and larval habit. The family is sometimes referred to informally as 'stem sawflies' or 'cephid sawflies,' though 'stem sawflies' can also encompass other families with stem-boring larvae. The superfamily Cephoidea is monotypic, containing only Cephidae. Identification to family level in the field relies on the combination of elongate body, reduced wing venation, and association with grass or sedge hosts.