Stem sawflies

Definition

A small superfamily of sawflies (Hymenoptera: Symphyta) comprising the family Cephidae and extinct Sepulcidae, characterized by slender, wasp-like bodies, diurnal activity, and larvae that bore into plant stems. Uniquely among Symphyta, they lack cenchri (the coupling structures between fore- and hindwings). They are sometimes hypothesized as sister to Apocrita, though Orussidae is more commonly proposed as such.

Etymology

From 'stem' for larval habit of boring into stems, plus 'sawfly' for placement in suborder Symphyta (historically distinguished by saw-like ovipositor, though reduced in this group).

Example

The wheat stem sawfly Cephus cinctus (family Cephidae) is a significant pest of cereal crops in North America, with larvae tunneling through wheat stems and causing lodging.

Synonyms

• Cephoidea

Related Terms

• Symphyta
• Cephidae
• cenchri
• Apocrita
• Orussidae
• stem borer
• sawfly

Usage Notes

The term refers specifically to the superfamily Cephoidea, not to any sawfly with stem-boring larvae; many other symphytan groups (e.g., some Tenthredinidae) also have stem-boring species. The common name is always plural in reference to the group; individual species may be called 'stem sawflies' or specified by genus (e.g., 'cephid sawflies'). Distinguish from 'stem borers,' a broader ecological category including beetles, moths, and other insects with similar habits.