Micropsectra polita (Malloch)

Namayandeh, Armin, Bilyj, Bohdan, Beresford, David V., Somers, Keith M. & Dillon, Peter J., 2012, 3324, Zootaxa 3324, pp. 1-65 : 59

Micropsectra polita (Malloch)

Figs 49A–G

Diagnosis. Labrum and premandible as in Fig. 49A; pecten epipharyngis with three toothed plates; labral lamella with tight row of 28 teeth; premandible with two apical teeth; antenna ( Fig. 49B) almost as long as head, pedestal ( Fig. 49C) with small apical spur, stalk of LO twice as long as segment 2, AR 2.14; mandible ( Fig. 49D) with slightly angled outer margin, but without lobe; mentum ( Fig. 49E) with toothed margin evenly arched; VM plate with narrow medial gap; posterior end of abdomen as in Fig. 49F; anal tubules curled ventrally; posterior parapod with about 60 claws arranged in horseshoe pattern.

Notes. Generally fits larval description given by Oliver and Dillon (1994), although the AR was outside the lower end of range (2.20–2.49). Cases ( Fig. 49G) are made of loose fine detritus, probably attached to rocks.

Ecology and habitat. Larvae have a preference for low order streams with maximum range temperature of 10–18 °C and slow seepage areas ( Oliver & Dillon 1994). Larvae occurred in all study streams in large numbers. They were the dominant species of Chironomidae in study streams.

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

Nearctic distribution. Canada: Alberta, Saskatchewan, Ontario, and Québec. USA: Pennsylvania, Maryland, South Dakota, Illinois south to Arizona.