This common name refers to only one genus. Click its scientific name to learn more.
The genus
Skwala (Short-winged Springflies) of the
Perlodidae family is represented by three species in North America,
Skwala americana, the identical-looking
Skwala curvata, and
Skwala compacta.
Skwala should be included in any comprehensive list of important stoneflies for the western flyfisher. Though often mistakenly thought of as members of the
Perlidae (Golden Stones) that happen to hatch early, they are actually quite different and often far more important on many western rivers than their more publicized cousins. Perhaps the most significant factors regarding this growing recognition are their inhabiting tailwaters previously too warm for trout and the lengthening of trout seasons, both relatively recent phenomena. This explains the scant mention they have received (if any) in older angling literature.
Excepting the lake dwelling
compacta, they are lovers of cobble bottomed riffles and runs of larger mid to low elevation rivers. Their behavior is consistent with other large stoneflies except that they are more prone to floating long distances as they placidly
oviposit, and with the exception of
Pteronarcys californica (Salmon Flies) in some locations, they do it in larger numbers. There is usually no challenge to them for the fish's attention until
Rhithrogena morrisoni (March Brown) mayflies begin to appear a few weeks later. Their flights occur during the warmest part of the day which usually means in the afternoon, though impressive flights have been observed around the lunch hour. Regardless, they finish well before dark.
The river-dwelling adults have smoky brown to brown wings, brown legs, and either primrose (often tinged w/ olive)
abdomens ribbed with brown or the reverse in darker strains. The males are
brachypterous, smaller and usually darker. Both sexes
thoracic ventrals are a curiously marked yellow/dark brown variegated pattern. Gravid females carry blackish pea shaped egg clusters off the tips of their
abdomens that are much larger in diameter.