The stonefiles (Plecoptera) of Saskatchewan : a thesis submitted to the Faculty of Graduate Studies and Research in partial fulfilment of the requirements for the degree of Master of Science in the Department of Biology, University of Saskatchewan

Abstract

Forty-one species belonging to 29 genera and eight families of the order Plecoptera are recorded from Saskatchewan. The distinguishing characters of the adults are described and keys are presented. The species collected include Pteronarcys dorsata (Say), Pteronarcella badia (Hagen), Taeniopteryx nivalis (Fitch), Oemopteryx fosketti (Ricker), Capnia coloradensis Claassen, C. confusa Claassen, C. gracilaria Claassen, c. vernalis Newport, Paracapnia angulata Hanson, Isocapnia crinita (Needham and Claassen), I. missourii Ricker, Utacapnia trava (Nebeker and Gaufin), Nemoura rickeri Jewett, Shipsa rotunda (Claassen), Amphinemura linda (Ricker), Zapada cinctipes (Banks), Malenka californica (Claassen), Podmosta delicatula (Claassen), Paraleuctra vershina Gaufin and Ricker, Leuctra ferruginea (Walker), Acroneuria abnormis (Newman), A. lycorias (Newman), Hesperoperla pacifica (Banks), Claassenia sabulosa (Banks), Paragnetina media (Walker), Perlesta placida (Hagen), Isoperla bilineata (Say), I. longiseta Banks, I. transmarina (Newman), I. patricia Frison, I. decolorata (Walker), I. marlynia Needham and, Claassen, I. petersoni Needham and Christenson, Arcynopteryx compacta (MacLachlan), Skwala parallela (Frison), Isogenoides colubrinus (Hagen), Isogenoides frontalis (Newman), Diura bicaudata (Linnaeus ) , Triznaka signata (Banks), Suwallia lineosa (Banks) and Hastaperla brevis (Banks). Nymphs of the following ten species are described for the, first time: O. fosketti, T. signata, S. lineosa, I. decolorata, N. rickeri, M. californica, P. delicatula, C. coloradensis, C. confusa and C. gracilaria. Keys to species are presented for mature nymphs except that nymphs of l. crinita and l. missourii are unknown, and nymphs of M. californica and A. linda are inseparable, as are nymphs of c. coloradensis from C. confusa and I. frontalis from I. colubrinus. The following information is presented for each species: selected literature references, distinguishing characters, biology and distribution which consists of a brief summary of the species range and a map showing Saskatchewan collection records. Taxonomically important characters are illustrated. Life history patterns and the seasonal succession of Saskatchewan Plecoptera are discussed. Saskatchewan stoneflies show a variety of life cycles ranging from being more than one year in duration to being univoltine. Some species with a one-year Iife history diapause as embryos, others do not. The post-glacial dispersal of stoneflies to Saskatchewan is discussed based on integration of the geographical and ecological distributions of extant species with the post-glacial history of Saskatchewan. The Saskatchewan stonefly fauna is derived mainly from post-glacial dispersal from refugia to the south and northwest of the ice sheets formed during the Wisconsin glaciation.