Microtendipes pedellus

Microtendipes pedellus (De Geer)

Figs 45A–F

Diagnosis. Frontal apotome separated from clypeus by a straight suture; labrum and premandible as in Fig. 45A; SI seta plumose; pecten epipharyngis with 3 subequal teeth; antenna (Fig. 45B) 6-segmented with LO alternately placed on segments 2 and 3, AR 1.0; mandible as in Fig. 45C; mentum (Fig. 45D) with two pale median teeth, occasionally with tiny central tooth, 6 lateral teeth, with the 1 st smaller, shorter than 2 nd; VM plates widely separated with coarse striations; posterior end of abdomen as in Fig. 45E; anal tubules curled ventrally.

Notes. This species is most commonly collected from lentic habitats, but is also known to occur in streams. The more common Microtendipes in small streams within the pedellus group is Microtendipes caducus Townes, which is difficult to separate. It has the LO situated apically on antennal segment 2; whereas in M. pedellus it is preapical. The genus is in need of revision including a species key for the larval stage.

Ecology and habitat. Larvae are known to build long sand retreats on rocks. Microtendipes larvae are filterfeeders (Hudson et al. 1990). In study streams they were only collected from pools. Reported for small lakes in Ireland, these species are bivoltine species with small scale emergences in late July to the end of the August, and the peak emergence from September to the end of the October (Bracken & Murray 1973).

Sampling sites. Algonquin Provincial Park

Nearctic distribution. Canada: Northwest Territories to New Brunswick. USA: From California east to Main and south to Florida.