Plecoptera - the stoneflies


Art by: C. Ruth Neudahl
Text by: Valerie Brady

Note the size of the real penny and use it to judge the size of the bugs in the following pictures.

Family: Perlidae, Common Stoneflies

stonefly larva

adult stonefly

Class: Insecta

Order: Plecoptera, the Stoneflies

Family: Perlidae, common stoneflies

Size: 0.5 to 1.5 inches (8-35 mm) plus tails

Habitat & Habits: Larvae are found only in streams, usually under stones in riffles. Speedy crawlers, these larvae cling to rocks and usually swim only when dislodged. Adults are found along stream edges in the spring and summer and live only a few weeks.

Feeding: Larvae are active predators, crawling under stones searching for mayflies, midges, and small caddisflies to eat. Adults probably feed on nectar for energy.

Water Quality Indicator: Larvae require cool, well-oxygenated running water and are very sensitive to nutrient pollution and sedimentation.