UPCOMING EVENTS
View full calendarKey to Aquatic Macroinvertebrates in Utah - Plecoptera
Aquatic organisms with 2 tails, or cerci, typically belong to the Plecoptera order-- also known as stoneflies. There are 8 families of stoneflies found in Utah. Stoneflies are considered one of three indicator species because of their high intolerance to pollution. They are typically found in clear, cold mountain streams.
(Family Name is Shown in Bolded Letters.)
Capniidae (winter stoneflies)
Description: 3-8 mm in size. Capniidae are small and elongate. They have parallel wing pads and relatively long cerci (tails). Adults typically emerge in winter and early spring.
Habitat: Commonly occur in small mountain streams and springs.
Chloroperlidae (sallflies)
Description: 5-12 mm in size. Chloroperlidae generally have no distinctive pigmentation, wingpads are parallel to the body and tails are shorter than the abdomen. They lack external gills.
Habitat: Most often found in cold mountain stream riffles on gravel substrate or woody debris.
Leuctridae (needleflies, rolled winged stoneflies)
Description: 4-10 mm in size. Leuctridae larva have light colored, elongate bodies. Without gills. They have parallel wingpads that are longer than wide.
Habitat: Commonly found in springs and small streams. Most of their time is spent burrowed deep in the substrate.
Nemouridae (forest flies)
Description: 3-8 mm in size. Nemourdiae have small, brown, hairy bodies. Gills occur in the cervix, or neck, region. The hind legs can extend past tip of abdomen.
Habitat: Commonly found in riparian debris in fast water with a coarse substrate.
Peltoperlidae (roach stoneflies)
Description: 8-15 mm in size. Peltoperlidae are brown without distinctive patterns. They have ventral gills on the thorax and large overlapping sternal plates that give them a roach like appearance.
Habitat: Commonly found in the sediments or detritus of flowing streams.
Perlidae (golden stoneflies)
Description: 8-35 mm in size. Perlidae are yellow and brown and distinctly patterned. They have highly branched gills on each thoracic segment and around coxal bases (armpit), and sometimes in the anal region.
Habitat: Found in a wide variety of swift moving water clinging onto rocks or crawling in moss.
Perlodidae (stripetails, springflies)
Description: 8-16 mm in size. Perlodidae may have contrasting light and dark patterns on their head and thorax. The cerci (tails) are generally 3/4 the length of their body. Some have simple finger-like gills on their neck, thorax, or abdomen.
Habitat: Typically found on the under side of larger cobbles and boulders.
Ptereonarcyidae (salmonflies)
Description: 15-50 mm in size. Pteronarcydiae are the largest of the stone flies. They have dark brown bodies and highly branched gills on each thoracic segment and the first two abdominal segments.
Habitat: Found In rapid moving fresh water in coarse leaf packs or the underside of large cobbles.
Taeniopterygidae
Description: 3-8 mm in size. Taeniiopterygidae have widely divergent wingpads. Often confused with Nemouridae, however, unlike Nemourids, the length of the 2nd tarsal segment is similar to the 1st tarsal segment. Few have a single gill near each coxae (armpit). If no gills, they have a sclerotized butt plate on the end of abdomen.
Habitat: Often found in slower waters than other stone flies. Commonly found in riparian debris.