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For Insects, Spiders & Their Kin
For the United States & Canada

Species Cephus cinctus - Wheat Stem Sawfly

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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)
Family Cephidae (Stem Sawflies)
Tribe Cephini
Genus Cephus
Species cinctus (Wheat Stem Sawfly)
Explanation of Names
Cephus cinctus Norton 1872
cinctus = 'belted, banded'
up to 10 mm(1)
NA (probably introduced, now transcontinental: PA-GA to BC-CA), ne. Asia (Altai to Kamtschatka & n. Japan)(1)
hosts: grain crops (esp. wheat), feral & native grasses (members of several Holarctic grass genera); in dry years, C. cinctus would literally starve on the truly native hosts(1)
Life Cycle
Larva overwinters within a wheat stub, under the ground. In the spring it pupates and emerges as an adult in June. The female lays a single egg and the larva feeds inside the stem until late summer.
females show little selectivity and would lay eggs into any available stem of the correct size, including those of plants where larvae will not mature(1)
details in(2)
earliest NA record: CO, NV 1872; major pest of wheat and other cereals since 1895 (economically important damage is concentrated in the n. Great Plains)(1)
Works Cited
1.On the geographic origin of the wheat stem sawfly (Hym.: Cephidae): a new hypothesis of introduction from northeastern Asia
Ivie M.A. 2001. American Entomologist 47: 84-97.
2.Wheat stem sawfly biology
Fulbright J., Wanner K., Weaver D. 2011. Montguide MT201107AG, 3 pp.