Identificaciones de henri_s

Cimbex americanus?

C. americanus can defoliate shade/ornamental elms and willows.

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. Females commonly have a yellow banded abdomen.

https://bugguide.net/node/view/37878