Representatives of Stonefly Families (Plecoptera)

Tips for identification- Stoneflies look similar to certain flattened mayflies and many beginners have trouble distinguishing the groups. The relative length of the antennae may be used to tell flattened mayflies from stoneflies. Stoneflies have antennae that are many times, four to six times, longer than the width of their head, while those of flattened mayflies are only about twice the width of their head.

Here are some other tips.

stoneflies always have two elongate tails
head with long slender antennae
each leg ends in two claws
length one quarter inch to two inches excluding antennae and tails

Family	Image	Details
Perlidae
Perlidae		Head with variable color patterns
Perlidae		Finely branched gills only on sides of thoracic segments, never extending to abdominal segments
Perlodidae		Tails equal in length or longer than abdomen
Perlodidae		No branching gills behind base of legs
Perlodidae		Metathoracic wingpads strongly diverging from body
Taeniopterygidae
Taeniopterygidae		With single gill at base of each leg or with triangular plate underneath next to last segment of abdomen
Taeniopterygidae
Taeniopterygidae		Tarsal segments 1 and 2 about same length
Nemouridae		Extended hind legs reaching approximately to end of abdomen
Nemouridae		Tarsal segment 2 much shorter than 1
Pteronarcyidae		Body black
Nemouridae		Some branching gills on ventral abdominal segments
Peltoperlidae		Thorax with large dorsal plates
Peltoperlidae		Thoracic sternal plates shield like, overlapping succeeding segment
Chloroperlidae		Nota usually without pigmented pattern. Tails 3/4 or less than length of abdomen. Abdominal terga widest posteriorly.
Chloroperlidae
Chloroperlidae
Capniidae		Abdominal terga widest posteriorly. (This family is very difficult to separate from the family Leuctridae)
Capniidae		Head
Capniidae		Paraglossa and glossa about equal in length.
Leuctridae		Abdominal segments essentially parallel-sided