Key to Stonefly Nymphs

First posted April 19, 2010 Last updated April 19, 2010


Explanation: there are two levels of keys of nymphs to the family level on this website. This key, called the "outline key" (I would love to call it the "skeleton key"), does not have pictures and is an overview of the key. Use it if you are familiar with keying plectoptera nymphs. In addition, each couplet is a hyperlink to the second key, called the "detailed key". It is a data-rich explanation of that specific couplet, with photographs or illustrations of the various options you face, and explanations that should help you to make the correct choice. You can move from the detailed key back to the outline key, to the next couplet of the detailed key.

I would love your feedback, criticism, or suggestions on how to make each choice clearer. I would also like submission of photographs that you feel would enchance the detailed key. Contact me at: NelsonDL at Pacbell dot Net.

Nymph key according to Stewart and Stark, 2002 , which in turn was modifed from Ricker (1959), Jewett (1968), Usinger (1968), and McCafferty (1981). This key is considered the definitive key to plecoptera nymphs for North America north of Mexico.

No gill tufts on abdominal sterna 2 or 3 Gill tufts on abdominal sterna 1 and 2, or on 1, 2, and 3    

Coxal gills and ventroapical abdominal plates absent,
second tarsal segment wedge-shaped and shorter than basal segment