Stoneflies

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Plecoptera:
”:folded “Ptera”: Wings
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Hind wings fold under front wings when resting
Often seen resting on stones
Adults found around lakes and streams in cool, temperate parts of the world
Nymphs live in cool, well aerated lakes and streams

•Small, ancient order of insects
•Earliest fossils from Permian
Period
Triassic: first mammals, first dinosaurs
Permian Period:
Formation of Pangaea
286,000,000 yrs.ago

• The Plecoptera order is divided into three suborders:
•Archiperlaria
•2 Families
•Filipalpia
•8 Families
•Setipalpia
•4 families

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In North America: 9
Families
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465 Species
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World wide: 15 families
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Over 2,000 species
Three Major Families:
Perlidae: Common Stoneflies
Nemouridae: Spring Stoeflies
Taeniopterygidae: Winter stoneflies

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Common stoneflies
Largest family
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Members most commonly collected

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Found in mountains of eastern and western
North America
Emerge into adult form in spring & summer

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Spring emerging
Small & brown
Common in N. America
“x” pattern of veination near apex of wings

•Medium sized, dark bodies Emerge in winter-spring
Taeniopteryx:
Common eastern and northern genus
Taenionema: common western group

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Most have wings
Reduced or absent in some species
Membranous

Three Tarsi and Two Claws
Cerci: long, multi-segmented Long, segmented antenna

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Mostly dull colored
Flat bodies
4-60 mm long
Hind legs not for jumping

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Body shape: flat and elongated
Cerci: long and multisegmented
Tarsi: 3 segments
Thorax: Covered with large dorsal sclerites
Gills: branched and fillamented.
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Sides of thorax and bases of legs

Thorax covered by dorsal sclerites
Legs widely separated
Long, segmented
Cerci

Reproduction &
Life Cycle
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Males drum to attract females
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Frequencies are species specific
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Normal sequence:
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Male drums, female drums back, male moves closer and drums again, female responds, cycle continues until they meet and mate.
Eggs deposited then hatch in 3-4 wks.
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Eggs deposited either loose in the water or in a jelly in the water
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Over 1,000 eggs deposited

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Live in rivers and lakes
Most have gills
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All require dissolved oxygen
Herbivorous and some carnivorous
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Algae, diatoms, moss, immature mayfiles
Molt 12-36 times, 1-2 yrs. to mature
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Full grown nymphs move to shoreline to molt one last time into adulthood.

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After emerging from water, fly or climb up nearby tree
Some adults feed, some do not
Non-feeding:
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Have fully formed eggs
 mate quickly… die a few days later
Feeding species:
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Females live for 4-5 weeks
Most males only live a few days

Drumming
Adult
Nymph
Boathouse
Mating
Eggs

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Indicate healthy streams and rivers
Important food source for game fish like trout and bass