Other Common Names
On guide pages, the common names used in
(1) are provided in the title; those used in
(2)(3) are listed as "Other Common Names"
Explanation of Names
Greek plektos 'twisted' + pteron 'wing'; refers to the folded posterior region of the resting hind wing
Numbers
Worldwide, ~3,400 spp. in ~300 genera of 18 families
(4); >670 spp. in >100 genera of 9 families in our area
(5) [600 spp. in the US
(2)]; of the two suborders one (~330 spp. in 6 families) is restricted to the southern hemisphere.
Species lists:
(2)(5)(4)(6)(7)
Genera not yet in the Guide are listed in
(8)
Overview of our fauna (* –taxa not yet in the guide; classification adapted from(5)(4)):
Order Plecoptera
Identification
Adult: four membranous wings held flat over the abdomen at rest; front wings narrower than hind wings; anal lobe of hind wing often folded fan-like at rest; wings of males may be reduced or absent; antennae long, slender, many-segmented; cerci often long
Nymph: body flattened and elongate with usually long cerci; most have tufts of branched filamentous gills on sides of thorax
online pictoral keys in
(9) •
keys to Michigan spp.
(10); guide to FL spp.
(11)
keys to NA genera for adults and nymphs in
(12)Range
Mostly cooler temperate parts of the world • range maps for NA species in
(2)(5)
Ranges/maps for all known taxa:
(4)Habitat
Nymphs primarily under stones in cool, clean, well-oxygenated unpolluted streams; some species 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
(13)Season
Adults of most species emerge during late spring and summer; some emerge and reproduce during fall/winter
Food
Nymphs feed on algae, diatoms, mosses, and aquatic invertebrates; most spring and summer adults do not feed, and are nocturnal; winter stoneflies feed on blue-green algae and 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
Can have up to 30+ nymphal stages
(14)Remarks
Nymphs of most spp. do not tolerate water pollution
Print References
Claassen P.W. 1931. Plecoptera nymphs of America (north of Mexico). Thomas Say Foundation Ent. Soc. Am. 3: 1-199.
Stewart K.W., Stark B.P. 1988. Nymphs of North American stonefly genera (Plecoptera). Thomas Say Foundation Ent. Soc. Am. 12: 1-460.
