THE IMMATURE STAGES AND BIOLOGY OF THE UNUSUAL NORTH-AMERICAN ARCTIC CADDISFLY SPHAGNOPHYLAX-MEIOPS, WITH CONSIDERATION OF THE PHYLETIC RELATIONSHIPS OF THE GENUS (TRICHOPTERA, LIMNEPHILIDAE)

Larvae and pupae of Sphagnophylax meiops Wiggins and Winchester, previ ously unknown, are identified from a transient arctic tundra pool near Tuktoyaktuk, Northwest Territories, Canada (69-degrees 29-degrees-N, 132-degrees 35-degrees-W). Surface water persisted in the basin of the pool, where larvae were evident for about 2 weeks in June, then reced ed into water-saturated organic materials above the permafrost, where larvae completed feeding, growth, and metamorphosis. The species has a univoltine life cycle, and adults emerge over a 5-week period from la te June to the end of July. Adults are brachypterous and evidently fli ghtless. Assignment of the genus Sphagnophylax to a tribe within the s ubfamily Limnephilinae is unusually complex. Long bristles on the fore wings are synapomorphic with the Chaetopterygini, but female genitalic structure suggests affinity with the Limnephilini. The genitalic stru cture of males indicates no clear relationship with the Limnephilini, but similar tendencies in some characters suggest distant affinity wit h the genus Philarctus, which is itself somewhat aberrant within the L imnephilini. The significance of these tendencies cannot be fully asse ssed until phylogenetic analysis of the subfamily Limnephilinae has be en carried out. The larval gill structure consisting of multiple filam ents in Sphagnophylax is shared with all of the Limnephilini, and is p robably an apomorphic character. The genus Sphagnophylax is assigned t o die tribe Limnephilini, and is interpreted as a relict group.