Mountain ash (Sorbus)-Pear sawfly (pear slug)

California pear sawfly (Pristophora abbreviata)

Pear slug (Caliroa cerasi)

Pest description and damage Pear slug is a European insect now found in most areas of the U.S. It attacks both pear and cherry and also is found on mountain ash, hawthorn, and ornamental Prunus. The adult is a glossy black fly-like insect, about 0.2 inch long. The larva initially resembles a small tadpole due to the olive-green slime that covers the body, and the head being wider than the rest of the body. Mature larvae are 0.375 inch long and orange-yellow. Larvae feed on the upper surface of leaves, skeletonizing them. Heavy feeding causes leaf drop, with reduction in vigor and yield, particularly on young trees. The pear sawfly is green in color, caterpillar-like and feeds along the leaf edges and may be difficult to detect.

For biology, life history, monitoring and management

See:

See "Sawfly" in:

Management-chemical control

See Table 2 in: