Capnia lacustra is a flightless species of stonefly only found in Lake Tahoe. It feeds on Chara, or skunkweed, a type of algae. Why do insects become flightless? Loss of wings occurs when insects that do not fly away from their location have better survival and fecundity than those that fly. Flight and the development of flight muscles requires energy and nutrients that could instead be used to produce eggs. In the case of Capnia lacustra, flying would result in higher predation mortality from aerial and terrestrial predators. After mating, flying stoneflies would need to return to the same locations where they developed for lack of suitable nearby alternative habitats to lay eggs. By not flying, the stoneflies suffer less mortality and produce more eggs. Since the Lake Tahoe habitat is relatively stable, staying and laying eggs is a better strategy than flying.
Capnia lacustra has two types of reproduction. Some females lay eggs that hatch in the water. Some females retain their eggs inside their body where they hatch and are birthed as larvae. This strategy is adaptive in a stable environment where resources for offspring to develop are not limiting and few nearby alternate sites exist.