Caddisflies of the Yukon - Department of Biological Sciences ...

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834 G.B. Wiggins and C.R. Parker FIG. 17. Approximate distribution of character states for tibial spurs in Brachycentrus americanus (Banks) (44) (Brachycentridae).
Caddisflies of the Yukon 835 Micrasema gelidum McLachlan (45) An intensive taxonomic analysis of this species complex was carried out by BotojAneanu (1988), who concluded from a study of male genitalic morphology that M. gelidum represents a polytypic superspecies of 6 prospecies, allopatrically distributed over a large part of northern Eurasia and North America. Three of the prospecies are represented in the Yukon and Alaska and in the Far East of Russia: M. (gelidum) gentile McLachlan (junior synonym M. scissum McLachlan, Kimmins and Denning 1951); M. (gelidum) extremum BotojAneanu; and M. (gelidum) gelidum McLachlan which also extends across the whole of northern Eurasia to Norway (junior synonyms: M. kluane Ross and Morse 1973; M. subscissum Martynov; M. sibiricum Martynov). Because M. gelidum is a member of a Nearctic group comprising M. bactro Ross, M. diteris Ross, M. onisca Ross, and M. sprulesi Ross, its origin was believed to have been in western North America (BotojAneanu 1988); and the mosaic of prospecies constituting M. gelidum was attributed to the isolation of populations during Pleistocene glacial periods and their recolonization following glacial retreat. Complexity within the superspecies M. gelidum was interpreted to indicate that glacial intervals preceding the last Wisconsinan period were effective in isolating populations for periods sufficient to effect morphological divergence. One form in the complex, M. (gelidum) canusa BotojAneanu (1988), occurs in central North America, and probably was isolated along the southern margin of the glacial ice; but the more northerly Nearctic forms were inferred to have passed periods of glacial advance in the Beringian refugium. As with species of Apatania, larval habitats for members of the gelidum complex broaden with increasing latitude—those in the most southerly localities living in spring streams, but northward habitats include rivers and also lakes in the most northerly localities (BotojAneanu 1988). Consequently larval habitat probably would not have been a deterrent to dispersal of the northern populations across the Bering land bridge during the Pleistocene, an inference further supported by occurrence of M. gelidum on the Arctic coastal plain (Fig. 1, region 1). Goeridae Goera tungusensis Martynov (47) The range of this species known originally from Siberia must now be extended to northern Quebec, the Northwest Territories, and almost certainly the Yukon (see Taxonomic Note 2). We also have from Alaska a pharate male that may represent a morphological variant of this species, or perhaps an unnamed sister taxon. If Pleistocene dispersal of G. tungusensis across the Bering land bridge to North America is indicated, the species could have extended eastward in North America after withdrawal of the glaciers. However, the widely scattered North American records suggest the possibility of repopulation of deglaciated areas from south of the ice where a pre-Pliocene circumboreal ancestor took refuge, and from which a disjunct Alaskan population has begun to diverge. Leptoceridae Ceraclea annulicornis (Stephens) (54) Phylogenetic analysis (Yang and Morse 1988) indicated that C. annulicornis is one of an unresolved group of 4 species—2 in China, and C. ruthae (Flint) from eastern North America. Species that are now transcontinental in North America, such as C. annulicornis, probably passed the Pleistocene to the south of the ice mass and if so, would have occurred in North America before glaciation.
Page 1 and 2: Caddisflies of the Yukon FRONTISPIE
Page 3 and 4: Caddisflies of the Yukon 789 and ta
Page 5 and 6: Caddisflies of the Yukon 791 impose
Page 7 and 8: Caddisflies of the Yukon 793 outlin
Page 9 and 10: Caddisflies of the Yukon 795 Genus
Page 11 and 12: Caddisflies of the Yukon 797 25. Ch
Page 13 and 14: Caddisflies of the Yukon 799 are de
Page 15 and 16: Caddisflies of the Yukon 801 53. Le
Page 17 and 18: Caddisflies of the Yukon 803 Family
Page 19 and 20: Caddisflies of the Yukon 805 85. Gr
Page 21 and 22: Caddisflies of the Yukon 807 Biolog
Page 23 and 24: Caddisflies of the Yukon 809 Biolog
Page 25 and 26: Caddisflies of the Yukon 811 Genus
Page 27 and 28: Caddisflies of the Yukon 813 FIGS.
Page 35 and 36: Caddisflies of the Yukon 821 above
Page 37 and 38: Caddisflies of the Yukon 823 was mu
Page 39 and 40: Caddisflies of the Yukon 825 recogn
Page 41 and 42: Limnephilus extractus Walker (99) L
Page 43 and 44: Apataniidae Apatania zonella (Zette
Page 45 and 46: Integripalpia Apataniidae Apatania
Page 47: Caddisflies of the Yukon 833 wester
Page 51 and 52: Caddisflies of the Yukon 837 been b
Page 53 and 54: Caddisflies of the Yukon 839 years,
Page 55 and 56: other reasons, most Palaearctic-Eas
Page 57 and 58: Caddisflies of the Yukon 843 In add
Page 59 and 60: Caddisflies of the Yukon 845 FIG. 2
Page 63 and 64: Caddisflies of the Yukon 849 press)
Page 65 and 66: Caddisflies of the Yukon 851 Pleist
Page 67 and 68: Caddisflies of the Yukon 853 Hydrop
Page 69 and 70: Caddisflies of the Yukon 855 TABLE
Page 71 and 72: Caddisflies of the Yukon 857 genera
Page 73 and 74: Caddisflies of the Yukon 859 strong
Page 75 and 76: Caddisflies of the Yukon 861 assure
Page 77 and 78: Caddisflies of the Yukon 863 Gislas
Page 79 and 80: Caddisflies of the Yukon 865 Reeves

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