Sawflies

Definition

Wasp-like insects of the suborder Symphyta (order Hymenoptera), distinguished from bees, wasps, and ants (suborder Apocrita) by a broad, unconstricted connection between thorax and abdomen lacking the narrow "wasp waist." The common name refers to the serrated, saw-like ovipositor used by females to slit plant tissue for egg-laying. The group includes approximately 8,000 described species, predominantly herbivorous larvae that feed externally on foliage, with some forming galls or mining stems. The superfamily Tenthredinoidea contains the majority of species.

Etymology

From the saw-like appearance of the female ovipositor used to cut into plant tissue for oviposition.

Example

The larch sawfly (Pristiphora erichsonii) is a destructive North American forest pest whose larvae defoliate larch trees; its broad thorax-abdomen junction distinguishes it from the constricted-waisted parasitoid wasps that sometimes attack it.

Synonyms

• Symphyta

Related Terms

• Hymenoptera
• Apocrita
• ovipositor
• Tenthredinoidea
• Gall wasps
• Stem sawflies

Usage Notes

Sawflies are paraphyletic with respect to Apocrita, meaning the suborder Symphyta does not include all descendants of its common ancestor. "Sawfly" properly refers to the entire suborder Symphyta, though colloquially and in some regional usage it may be restricted to the superfamily Tenthredinoidea; woodwasps (Siricidae) and horntails are technically sawflies but are often treated separately in applied contexts. The larval stage, not the adult, typically causes economic damage and is often mistaken for caterpillars (Lepidoptera larvae), but sawfly larvae possess more pairs of prolegs (6-8) and lack the crochets (hooked spines) found on lepidopteran prolegs.