Figs 20A–D

Diagnosis. SI simple serrated; premandible with one apical tooth, no brush; antenna (Fig. 20A) 5-segmented, 3 rd segment shorter than 4 th, no apparent LO, blade distinctly longer than flagellum, AR 1.6; mandible (Fig. 20B) with two large inner teeth, apical tooth shorter than combined width of inner two, seta interna with 7 plumose branches; mentum (Fig. 20C) with single dome-shaped median tooth, 4 laterals, last one may be bifid or notched, lateral margin with sclerotized posterior extension; VP plates distinct originating from outer margin of first lateral tooth and ending at level of seta submenti; posterior end of abdomen as in Fig. 20D; procercus absent, one strong apical seta and 3–4 short weak setae at the base; anal tubules very long tapering about 4–5x as long as posterior parapod (when fully extended).

Notes. The larva fits the species description given by Saether & Sublette (1983), but should be considered tentative until the larvae have been associated for the other three species in the subgenus Georthocladius, particularly Georthocladius (Georthocladius) triquetrus Saether et Sublette which is also an eastern species (North Carolina).

Ecology and habitat. Reported in bogs, seeps and lotic habitats (Epler 2001).

Sampling sites. Parry Sound District.

Nearctic distribution. First published record for Canada: Ontario. USA: Tennessee, Florida.