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Order Plecoptera: the stoneflies — Examples
Midwestern Salmonfly, also known as Giant Stonefly, Pteronarcys pictetii, Order Plecoptera.
□ Adult Midwestern Salmonflies, or Giant Stoneflies, can grow to more than an inch (2.5 cm) long.
Photographed by: Mike Wifler. Submitted by: Shawna Fischer. Identified by: KnowYourInsects.org.
Location: Des Moines, Iowa, USA.
Date: 5 June, 2018.
Shawna says, “I had never seen anything like it.”
Giant Stonefly in the genus Pteronarcys, Order Plecoptera.
□ Stoneflies are in the scientific order Plecoptera. The -ptera part of the name is common to the names of many insect orders, and means wing. The pleco- part of the name means braided and refers to the beautiful and complex veining in their wings.
Photographed by: Shelly Papp. Submitted by: Mary Kay. Identified by: KnowYourInsects.org.
Location: near the Allegheny River in northwestern Pennsylvania, USA.
Date: 12 April, 2020.
Giant Stonefly, also known as a Giant Salmonfly, in the genus Pteronarcys, quite possibly Pteronarcys californica, Order Plecoptera.
□ The species Pteronarcys californica is becoming quite rare, so this is a great find!
□ The larvae of Stoneflies live underwater, and the adults (like this one) live on land. Stonefly larvae are often used by ecologists to indicate the health of a stream because they must have cool and clean water to survive. For this reason, Stoneflies are called environmental-indicator species.
Photographed by: Barbara Holbrook. Submitted by: Angie Fox. Identified by: KnowYourInsects.org.
Location: Enumclaw, Washington, USA.
Date: 11 April, 2020.
Angie says, “It is about 2” long (5 cm) and really something we’ve never seen before.”
Stonefly, naiad (immature), Order Plecoptera.
□ Stonefly naiads live in swiftly moving streams or rivers, usually on the underside of submerged rocks. They require highly oxygenated water to survive.
□ Depending on the species (the species of this one is unknown), the naiads may be herbivorous or carnivorous.
Photographed by: Judith Strengholt. Identified by: KnowYourInsects.org.
Location: Swiss Alps.
Date: 7 January, 2020.
Judith says, “I took this picture of a spider web. When I looked at the picture at home, I saw a mysterious insect on the background.”
Stonefly, shed skin (exuviae) of a naiad (immature), Order Plecoptera.
□ Immature Stoneflies live underwater (technically they’re called naiads), then crawl onto shore to go through their last molt and become a winged adult. When they do that final molt, the discarded shell, called the exuviae and seen here, remains behind.
Photographed by: Barb Ohmer. Submitted by: Chris Puls. Identified by: KnowYourInsects.org.
Location: Brewster River Park, Vermont, USA.
Date: 24 August, 2018.
Barb says, “Oh, that’s so cool!”
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Photos at the top of this website are (from left to right): potato beetle (Leptinotarsa decemlineata) — photo credit: Scott Bauer, U.S. Department of Agriculture; ebony jewelwing (Calopteryx maculata)— photo credit: U.S. Fish and Wildlife Service; sweat bee (Agapostemon splendens) — photo credit: Natalie Allen and Stephanie Kolski, U.S. Geological Survey; preying mantis, monarch butterfly (Danaus plexippus), hellgrammite (aka toe biter) larva and eyed click beetle (Alaus oculatus) — photo credit: Leslie Mertz; Halloween pennant (Celithemis eponina) — photo credit: Kay Meng, U.S. Fish and Wildlife Service.
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