Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada

"Symphyta" - Sawflies, Horntails, and Wood Wasps

Parasitic Wood Wasp - Orussus terminalis Cimbicid Sawfly - Abia inflata - female pigeon tremex - Tremex columba - female Sawfly Tenthredinidae - Tenthredo reg legged sawfly perhaps? Tenthredinidae sawfly larva Sawfly eating green immigrant weevils - Tenthredo
Classification
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Hymenoptera (Ants, Bees, Wasps and Sawflies)
No Taxon "Symphyta" - Sawflies, Horntails, and Wood Wasps
Synonyms and other taxonomic changes
A paraphyletic grouping of basal hymenopteran lineages; phylogenetic relationships summarized in (1)
Explanation of Names
"Sawfly" refers to the sawlike ovipositor cutting into plant tissues
Numbers
~8000 spp. in ~800 genera of 14 families worldwide; 1245 spp. in ~140 genera of 13 families in the Nearctic Region(2) and 1100 spp. in our area (Dave Smith's estimate, pers. comm. to =v= 5/2/10); >700 spp. in Canada(3), ~350 in VA(4)
Identification
The adults lack the characteristic "wasp waist". Females may have conspicuous ovipositors but are unable to sting.
Larvae resemble caterpillars (how to distinguish) but have at ≥6 pairs of prolegs (≤5 in lep larvae, except for Megalopygidae, which have 7); others are legless and may be slimy (often called 'slugworms' or just 'slugs').
Keys to genera of Canada & n. US in (3)(5) • keys to families and references to further identification in (6)
OVERVIEW OF FAMILIES











Range
Worldwide and throughout NA
Food
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. Orussidae are parasitic. Some adult sawflies feed on nectar or pollen.(7)
Life Cycle
Usually have one generation a year and overwinter as mature larva or pupa in a cell/cocoon in the ground or other protected place; in larger spp. the cycle may take more than one year(7)
Internet References
(8)
Works Cited
1.Evolution of the Insects
David Grimaldi and Michael S. Engel. 2005.
2.Blank et al. (2012) ECatSym: Electronic World Catalog of Symphyta (Insecta, Hymenoptera). Program version 4.0 beta
3.The genera and subgenera of the sawflies of Canada and Alaska (Hymenoptera: Symphyta)
Goulet H. 1992. The insects and arachnids of Canada, Pt. 20. Ottawa: Agriculture Canada. 235 pp.
4.List of the Sawflies (Hymenoptera: Symphyta) of Virginia
Smith D.R. 2006. Banisteria 28: 3‒23.
5.Sawfly GenUS
6.Hymenoptera of the world: an identification guide to families
Goulet H., Huber J., eds. 1993. Agriculture Canada Publication 1894/E. 668 pp.
7.Borror and DeLong's Introduction to the Study of Insects
Norman F. Johnson, Charles A. Triplehorn. 2004. Brooks Cole.
8.Green A.J. (2021) The Sawflies (Symphyta) of Britain and Ireland