Stoneflies and Cadisflies

Stoneflies (order Plecoptera), freshwater inhabitants, are close relatives of the terrestrial insect we know as the cockroach. There are estimated to be about 500 known species of stoneflies in North America. They are thought to have been given their common name by virtue of the fact that they reside in the crevices of the stones and pebbles along the edges of streams, rivers, ponds, and other rocky, shallow bodies of water. Ecologically, some are considered excellent clean-water indicators in freshwater habitats. They require very clean, well oxygenated water for their survival. Their lifecycle may span a year for some species with metamorphosis including up to 22 instar changes before it is complete and the adult emerges with fully functioning wings and reproductive capability.

Cadisflies (order Trichptera) are included here because they share a common habitat with the stoneflies. Cadisflies are highly advanced insects in their evolutionary development; placing them as close relatives to the Lepidoptera, butterflies. This moth-like adult has 'hairy' wings and is not colorful, rather a bland brown to beige. The cryptic coloration allows the adults to blend into their environment and avoid heavy predation pressure from birds, shrews, and amphibians. During their larval stage, this insect constructs an elaborate 'house' around its soft body. Tiny pebbles, sticks, and mud are held in place by a mortar-like substance secreted by the larvae. The 'house' resembles a small stone tube or chimney that is perfectly camouflaged against the background of the cadisflies' habitat.