European apple sawfly

The European apple sawfly overwinters as a mature larva in a cocoon a few inches below the surface of the soil. The larva pupates early in the spring and emerges as an adult "fly" or wasp (Fig. 1) about the time apple trees come into bloom. Adults are 6 to 8 mm in length, with the male smaller than the female. The head is yellow with yellow antennae and black eyes. The wings are covered with tiny black hairs, giving them a dusky appearance. The body is brown; the upper surface appears almost black and shiny and the lower surface lighter and orange to yellow. The males emerge first in the season, and as the season progresses both sexes can be found flying unsteadily about the blossoming apple trees. When they alight, they move rapidly around, quickly vibrating their antennae. The adults apparently feed on pollen and are most active when the sun is intense, usually around midday. The average adult life span is from one to two weeks.