Sawflies Basking on Sunny Surfaces

Sawfly adults are shiny 3/8-inch long wasps with shiny black bodies that may be marked with other colors.  They have long, thin, black antennae and two pair of wings held flat over their backs.

Adult sawflies bask on sunny surfaces (especially sides of light-colored houses or structures) in early spring, rest on foliage, or collect liquid from buds. They soon fly away without causing harm.

Figure 1. Grass sawfly adult. (Photo: Lee Townsend, UK)

Figure 1. Grass sawfly adult. (Photo: Lee Townsend, UK)

Sawfly wasps cannot sting and pose no threat to humans or pets. Soon females will be laying eggs and the caterpillar-like larvae will begin to feed on plants.  The grass sawfly is common in spring, and their light green larvae feed on grasses.  They are rarely present in damaging numbers, so there is no need to control adults or immature stages.


By Lee Townsend, Extension Entomologist



Posted in Lawn & Turf