Monday, 30 July 2018

Insect of the Week (July 30, 2018) - Wheat stem sawfly (Cephus cinctus, Hymenoptera: Cephidae)

This week's Insect of the Week is the wheat stem sawfly (Cephus cinctus). Adults are 8-13mm long and have a shiny, black, wasp-like body and yellow legs. When at rest on plant stems, they point their heads downwards.
Mature larvae overwinter in the base of stems in infested fields. In June, females emerge and fly to nearby wheat crops, where they can lay up to 50 eggs each on stems.

The wheat stem sawfly feeds primarily on spring and durum wheat, though winter wheat, rye, grain corn, barley, and some native grasses can support sawfly development. It cannot develop on oats.

Larvae feed on the pith of host plants stems which can cause a reduction in crop yield and quality. When plants mature, larvae move to the bottom of the stem to overwinter.

For more information about the wheat stem sawfly, head over to our Insect of the Week page!

Wheat stem sawfly - adult
(Alberta Agriculture and Rural Development)
Wheat stem sawfly - egg, larva, adult, damage
(Art Cushman, USDA Systematics Entomology Laboratory,