Leptophlebiidae
Prong-gilled Mayflies
There are about 70 North American species in this family. Larvae tend to be found in gravel-bottomed streams, with woody debris, or among roots along banks; however, some can be found in lentic situations. Mature larvae are 4–15 mm long. They tend to be clingers and moderately fast swimmers. Most feed by collecting and gathering food, however, some scrape periphyton from rocks or gather particles of detritus, others filter particles from the water. The gills are often forked, giving them the name “Pronggills”. We like to refer to their gills as deciduous, because they are extremely fragile and fall off the insect readily, like autumn leaves. They have relatively flat bodies, and thus can be easily mistaken for Heptageniidae, however, they can be distinguished because the mandibles protrude at the side of the face making them visible dorsally.