• 626 species in 9 families in North America
  • Most are highly sensitive pollution and group is widely used in water quality monitoring
  • Most occur in small, cool, swift streams
  • Absence in larger warm streams does not necessarily indicate water quality issues
Phylum:Arthropoda
Class:Insecta
Order:Plecoptera
Family:

Identification Tips:

Larvae
• Elongated bodies with two tails and six segmented legs
• No gills on abdomen
• May be gills on thorax at base of legs or throat area
• 2 claws at end of each leg

Adults
• Elongate flattened, soft bodies
• Membranous wings with many veins
• Wings folded lie flat over the abdomen with hind wings hidden under front wings
• Tips of front and hind wings even and extend beyond abdomen when folded
• Two long, thin antennae extend from front of head

Life History:

• Almost all are found in cool running waters with high levels of dissolved oxygen
• Typically found on coarse substrates like rock, wood or organic debris
• Most species are crawlers
• May feed on detritus or be predatory
• Life cycle typically completed in 1 to 2 years
• Most spend 10-11 months as larvae
• Adults emerge in spring or early summer, but are nocturnal and rarely seen

POLLUTION TOLERANCE
Very SensitiveSomewhat SensitiveFacultativeSomewhat TolerantVery Tolerant
MostSomeSome  
Pollution IndicatorOne of the 'EPT ' families (Plecoptera) commonly used as indicators of good water quality

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Primary Information Source:
Voshell, J. Reese. 2002. A Guide to Common Freshwater Invertebrates of North America. McDonald and Woodward Publishing Company. Blacksburg, Virginia.