Psilometriocnemus triannulatus Saether

Namayandeh, Armin, Bilyj, Bohdan, Beresford, David V., Somers, Keith M. & Dillon, Peter J., 2012, 3324, Zootaxa 3324, pp. 1-65 : 43

Psilometriocnemus triannulatus Saether

Figs 34A–F

Diagnosis. SI seta apically dissected; pectin epipharyngis with three peg-like scales; premandible with two teeth; antenna 6 segmented, the last one hair-like barely visible, segment 3 is 0.25x as long as segment 4, blade about as long as flagellum, 5 segmented; AR 0.9 (see Notes); mandible with there inner teeth; mentum with broad bifid median tooth, 5 lateral teeth, last outer two reduced and share a common base; VM plate distinct, originating from the outer margin of first lateral and ending with a posterordorsal extension; setae submenti placed at a level posterior to the plates; procercus with 3 strong apical setae with bulbous bases and 6 fine setae that appear to be arising more laterally; anal tubules elongate about same length as posterior parapods; supraanal seta with basal spinules.

Notes. Generally in agreement with description of larva given by Saether (1982: 486) as Psilometriocnemus cristatus Saether. The AR is determined from a 5-segmented antenna.

Ecology and habitat. Species inhabit springs and cool headwater streams ( Ferrington et al. 1995).

Sampling sites. We found the larvae inhabiting streams in all the provincial parks and districts located in our study area.

Nearctic distribution. Canada: New Brunswick, Nova Scotia, Ontario, Québec. USA: Florida, Georgia, Kansas, Minnesota, New Hampshire, Ohio, North Carolina, South Carolina, Tennessee .