February 22, 2009 - Snowflies

Welcome to the Nature Notebook.

We rarely think of insects being active in winter, especially those that live in water. Most aquatic insects emerge in spring and summer to mate and lay eggs. But some stoneflies appear to be the exact opposite, with adults emerging in mid- to late winter. As their name implies, stoneflies are found in streams and rivers with rocky bottoms. Because they need highly oxygenated water they are indicators of good water quality. Male stoneflies start to emerge before females. These small, dark, elongated insects are weak fliers and hold their highly-veined wings over their backs. They can appear on the ground along streams, walking on snow or climbing rocks, vegetation and bridges. Males attract females by “drumming” against their perch. Because of their winter emergence, these early stoneflies are also known as snowflies.

This is PPL's naturalist, Jon Beam, with the Nature Notebook for WVIA.