Order Plecoptera - Stoneflies
Classification Kingdom Animalia (Animals)
Phylum Arthropoda (Arthropods)
Class Insecta (Insects)
Order Plecoptera (Stoneflies)
Other Common Names Family names used in Peterson's Field Guide (1) are in parentheses below; names used in flyfishing are in brackets.
Capniidae: (Small Winter Stoneflies) [Snowflies]
Chloroperlidae: (Green Stoneflies) [Sallflies]
Leuctridae: (Rolled-winged Stoneflies) [Needleflies]
Nemouridae: (Spring Stoneflies) [Forestflies]
Peltoperlidae: (Roachlike Stoneflies) [Roachflies]
Perlidae: (Common Stoneflies) [Stones]
Perlodidae: (Perlodid Stoneflies) [Stripetails and Springflies]
Pteronarcyidae: (Giant Stoneflies) [Salmonflies]
Taeniopterygidae: (Winter Stoneflies) [Willowflies]
Explanation of Names PLECOPTERA: from the Greek "plektos" (twisted) + "pteron" (wing); refers to the folded posterior region of the resting hind wing Numbers nearctica.com lists 623 species in 9 families
Mississippi College lists 618 North American species in 9 families, along with states/provinces of occurrence for each species
Insects of Cedar Creek cites "465 North American species" in 9 families
about 2,000 species worldwide Size adult length 4-60 mm Identification Adult: drab colored with four membranous wings held flat over the abdomen when at rest; front wings narrower than hind wings; expanded anal lobe of hind wing often folded fan-like at rest; wings of males of several species reduced or absent; antennae, long, slender, many-segmented; abdominal cerci often long and prominent; mouthparts adapted for chewing
Nymph: body flattened and elongate with two, usually long cerci; most nymphs have tufts of branched respiratory gills on sides of thorax and around bases of legs; the gills are filamentous, not plate-like or leaf-like Range mostly the cooler, temperate parts of North America and the world Habitat nymphs occur primarily under stones in cool unpolluted streams; some species occur along rocky shores of cold lakes, in cracks of submerged logs, and debris that accumulates around stones, branches, and water diversion grills
spring and summer adults may be found resting on stones and logs in the water, or on leaves and trunks of trees and shrubs near water; winter stoneflies are often attracted to concrete bridges over streams, and some species are commonly found on snow or resting on fence posts during the warmer days of late winter
[Roger Bland, How to Know the Insects] Season adults of most species emerge during late spring and summer; however, adults of many species emerge and reproduce during the fall and coldest parts of the winter (the so-called "winter" stoneflies) Food nymphs feed on algae, diatoms, mosses, and immature aquatic invertebrates, including mayflies and midges
most spring and summer adults do not feed, and are nocturnal; winter stoneflies are day-flying, and feed on blue-green algae and plant foliage Life Cycle females deposit several egg masses, which together may total more than 1,000 eggs, by flying over water or occasionally by crawling up to the water; some nymphs are known to molt 12-36 times, and require one to three years to mature; full-grown nymphs leave the water, cling to shoreline vegetation and debris, and molt into the adult stage Remarks stonefly nymphs depend upon cool, well-oxygenated water for their development, and are intolerant of pollution; therefore, their presence is an indicator of good water quality, and their absence in areas where they previously occurred may indicate polluted water See Also nymphs of mayflies (Ephemeroptera) are similar but all except a few genera have three caudal filaments, and their gills are leaf-like and located on the sides of the abdomen Print References Bland, Roger G., and H.E. Jaques. 1978. How to Know the Insects. 3rd Edition. Wm. C. Brown Company Publishers. Internet References live adult and nymph image by C. Riley Nelson, plus classification, biology, habitat, description, phylogeny, references (Tree of Life, U. of Arizona)
overview of order Plecoptera plus links to info on families (John Haarstad, Insects of Cedar Creek, U. of Minnesota)
distribution of 618 North American species, listing states/provinces of occurrence (Mississippi College)
US distribution maps for most species (Stoneflies of United States, USGS)
pictorial key of families and some genera - 20 diagrams showing differences in wing venation, with distinctive characters circled in red (Jurgen Gaul, Germany) Works Cited | 1. | A Field Guide to Insects
By Richard E. White, Donald J. Borror, Roger Tory Peterson |  |
| 
