REVISION OF THE ONOCOSMOECUS UNICOLOR GROUP 
(TRICHOPTERA: LIMNEPHILIDAE, DICOSMOECINAE) 
By Glenn B. Wiggins 1 and John S. Richardson 2 
Introduction 
The genus Onocosmoecus, by current definition, comprises the 
unicolor group and the frontalis group (Schmid 1980, occidentalis 
group = unicolor group; Wiggins 1977). From a separate study of 
generic relationships within the Dicosmoecinae (G. B. Wiggins & O. 
S. Flint, in prep.), it is clear that Onocosmoecus in this broad sense 
is not monophyletic. The frontalis group will be considered in a 
subsequent paper, but in the interim the two western North Ameri- 
can species of which it is composed, O. frontalis (Banks) and O. 
schmidi (Wiggins), remain nominally under Onocosmoecus. Thus, 
in final analysis, this study of the unicolor group will constitute a 
revision of the genus Onocosmoecus s.s., and the generic name is 
used here in that restricted sense. 
Among the genera of the limnephilid subfamily Dicosmoecinae, 
Onocosmoecus s.s. is one of the most widespread, represented 
across the whole of northern North America from Newfoundland to 
Alaska, south in the western mountains to California, and across 
the Bering Strait to Kamchatka. They are rather large caddisflies, 
not often found in abundance but by no means rare. Larvae occur in 
cool lotic habitats, and also in the littoral zone of cool lakes, where 
they are detritivorous. Seven species have been assigned to the genus 
in the past but reservations concerning their validity have been 
expressed by several authors (e.g., Schmid 1955, 1980; Flint 1960; 
Wiggins 1977). Because no analysis of types or of long series of 
specimens has been undertaken, identity of the putative species has 
always been doubtful. The purpose of the present study was to 
undertake that analysis. 
'Department of Entomology, Royal Ontario Museum, 100 Queen’s Park, Toronto, 
Ontario, Canada MSS 2C6. 
department of Zoology, University of British Columbia, Vancouver, B.C. Canada. 
Manuscript received by the editor June 17. 1986. 
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