Elm Sawfly

Description:

The largest North American sawfly. Larvae yellowish-white with black dorsal stripe. While feeding, the larvae usually coil their posterior around a leaf or twig. At rest the larvae roll into a characteristic tight coil. The larvae spin tough, papery cocoons in the litter or just below the surface of the soil. Pink coloration is not common, most larvae are green to yellow in color. Adult has glabrous thorax with white/yellow spot above, orange antennae.

Habitat:

hosts include elm (Ulmus), maple (Acer), birch (Betula), willow (Salix), and basswood (Tilia); adults girdle bark on twigs. Not considered a forestry problem, but can defoliate shade/ornamental elms and willows (Forestry images)