"Symphyta" - Sawflies, Horntails, and Wood Wasps

a paraphyletic grouping of more basal hymenopteran lineages, previously known as Symphyta; phylogenetic relationships summarized in(1). The families are arranged into 7 superfamilies, of which Tenthredinoidea, with 6 families (Argidae, Blasticotomidae, Cimbicidae, Diprionidae, Pergidae, Tenthredinidae), is by far the largest. Siricoidea includes Anaxyelidae and Siricidae; Pamphilioidea, Megalodontesidae (=Megalodontidae; not in our area) and Pamphiliidae; the rest of the families are classified in its own superfamily each.(2)

"sawfly" refers to the sawlike ovipositor cutting into plant tissues to deposit eggs(3)

about 8000 spp. in ca. 800 genera of 14 families worldwide; 1245 spp. in ca. 140 genera of 13 families in the Nearctic Region(4)(5) and 1100 spp. in our area (Dave Smith's estimate, pers. comm. to =v= 5/2/10); over 700 spp. in Canada(6)

(the only family still missing in the guide is monotypic Anaxyelidae from the Pacific Coast; the only family not represented in our area is Megalodontesidae, restricted to temperate Eurasia)

The adults may resemble other hymenopterans, but lack the characteristic "wasp waist". Females may have conspicuous, impressive ovipositors but are unable to sting.

Many sawfly larvae resemble lepidopteran caterpillars, but have at least six pairs of prolegs (no more than five pairs in caterpillars, with the exception of the Megalopygidae, which has 7); others are legless and may be slimy (often called 'slugworms' or just 'slugs').

Keys to genera of Canada & n. US in(6)

OVERVIEW OF FAMILIES

worldwide and throughout NA

Most sawfly larvae feed externally on tree/shrub foliage; some mine leaves, a few form galls. Some bore in stems (Cephidae), fruits, or wood (horntail and woodwasp larvae), and in those legs are reduced or absent. The parasitic family Orussidae is the only exception. Some adult sawflies feed on nectar or pollen.(3)

Usually have one generation a year and overwinter as mature larva or pupa in a cell/cocoon in the ground or in otherwise protected place; in larger spp. the cycle may take more than one year(3)

Symphytos (site not updated since 2003)