Macropelopia decedens (Walker)

Namayandeh, Armin, Bilyj, Bohdan, Beresford, David V., Somers, Keith M. & Dillon, Peter J., 2012, 3324, Zootaxa 3324, pp. 1-65 : 12

Macropelopia decedens (Walker)

Figs 6A–I

Diagnosis. Head large oval, pale yellowish brown including posterior margin and gular sclerite; maxillary palp ( Fig. 6A) with RO located in the basal third; antenna ( Fig. 6B) 4-segmented, flagellum as in Fig. 6C, 3 rd segment sitting on membranous pedestal; mandible ( Fig. 6D) with small basal tooth pointed apically; dorsomental plates ( Fig. 6E) present with 6 large teeth plus 1 small outer lateral and small one fused to short medial projection; pseudoradula with granular surface coarser and expanded near the middle; ligula ( Fig. 6F) with long outer laterals about twice the length of median tooth, inner laterals turned slightly outwards; ventral cephalic setae and VP as in Fig. 6G, S 9 and S 10 long simple setae, SSm seta with multi-branched, slightly anterior to S9, VP posterolateral of S9 and S10; body with weak lateral fringe extending to abdominal segment 6; posterior end of abdomen as in Fig. 6H, procercus with 12–13 apical setae; small claws on posterior parapods with drawn-out thin bases ( Fig. 6I).

Notes. So far this is the only known Nearctic species, and our specimen agrees with Roback’s (1978) larval description.

Ecology and habitat. Larvae were mainly found in moss. Larvae feed on smaller invertebrates, including Protozoa, Ostracoda, Crustacea and Ceratopogonidae ( Roback 1978) . The species is reported to occur in streams with temperature 14–18°C (X = 13°C), pH 6.01–7.0 (X = 6.8) and altitude 305–609m ( Roback 1978).

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

Nearctic distribution. Canada: British Columbia, Ontario, Québec, Saskatchewan. USA: Colorado, Florida, Kentucky, Maine, Massachusetts, Michigan, Mississippi, New Hampshire, North Carolina, Ohio, Pennsylvania, Rhode Island, Tennessee, Utah, Wyoming .