Chaetocladius ( Chaetocladius ) ligni Cranston et Oliver

Chaetocladius ( Chaetocladius) ligni Cranston et Oliver View in CoL

Figs 11A–E

Diagnosis. Labrum as in Fig. 11A, SI seta simple; premandible ( Fig. 11B) with one apical and one inner tooth, and weak brush; antenna ( Fig. 11C) 5-segmented, with 3 rd segment subequal to 4 th, large LO, AR 1.2; mandible ( Fig. 11D) with 4 inner teeth; mentum ( Fig. 11E) with broad bifid median tooth, 4 lateral teeth (5 th vestigial or absent), with pale vertical “grooves”; VM plates small originating from 1 st lateral tooth; (abdomen missing).

Notes. The species is not typical in having a simple SI (usually serrated or divided), single apical tooth (usually two) on premandible and an overhanging abdominal segment 9, with the procerci directed posteriorly ( Cranston & Oliver 1988).

Ecology and habitat. As xylophagous species, larvae are wood miners ( Cranston & Oliver 1988, Saether 1983). Unlike Orthocladius ( S.) lignicola larvae that were often encountered when sorting through the samples, larvae of this species were only found by detailed examinations of woody debris. Generally Chaetocladius species have a temperature preference of 6.6–9.3°C ( Rossaro 1991).

Sampling sites. Killarney and Arrowhead Provincial Parks and Muskoka District

Nearctic distribution. First published record for Canada: Ontario. USA: Oregon , North and South Carolina.