Immature Stages of Plecoptera
Detailed information on immature stages of Plecoptera is being acquired. Clausen (1940), however, noted that the nymphs of most species feed on aquatic vegetation, and only in the Perlidae, especially the genera Perla and Acroneuria, are they essentially carnivorous. The mouthparts of the nymphs are definitely modified because of this behavior. Frison (1935) noted that the predaceous species are found in families Perlidae, Perlodidae and Chloroperilidae. The last family shows a wide range in food habits.