Identification, Images, & Information
For Insects, Spiders & Their Kin
For the United States & Canada
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Fall Fund Drive


Family Pteronarcyidae - Giant Stoneflies

Giant Stonefly larva - Pteronarcys biloba Insect - Pteronarcys californica California Giant Stonefly - Pteronarcys Pteronarcys biloba Idaho Stonefly - Pteronarcys big thingy - Pteronarcys Giant Stonefly - Pteronarcys Pteronarcys sp.? - Pteronarcys
Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Subphylum Hexapoda (Hexapods)
Class Insecta (Insects)
Order Plecoptera (Stoneflies)
Superfamily Pteronarcyoidea
Family Pteronarcyidae (Giant Stoneflies)
Other Common Names
Synonyms and other taxonomic changes
2 genera, with 10 spp. in our area(1) and 12 spp. total(2)
adult body length 25-60 mm
Adult: dark brown, gray, or blackish; anal area of forewing with two or more rows of cross veins (a diagnostic feature)
Nymph: branched gills on ventral side of thorax and first two abdominal segments (the abdominal gills are often visible from above)
NA + most of Asia(2)
most nymphs develop in medium to large rivers; adults are nocturnal and often come to lights
adults appear in spring and early summer
nymphs feed on aquatic plants, adults do not feed
See Also
some spp. of Acroneuria (Perlidae) are large (to 40 mm) and look similar but lack rows of cross veins in anal area of forewing; nymphs of Perlidae have thoracic gills but not abdominal gills