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

Limnephilus extractus Walker (99)
Limnephilus hageni Banks (103)
Limnephilus hyalinus Hagen (104)
Limnephilus infernalis (Banks) (105)
Limnephilus janus Ross (106)
Limnephilus kennicotti (Banks) (107)
Limnephilus partitus Walker (110)
Limnephilus parvulus (Banks) (111)
Limnephilus perpusillus Walker (112)
Limnephilus sansoni Banks (115)
Limnephilus secludens Banks (116)
Limnephilus sublunatus Provancher (119)
Limnephilus tarsalis (Banks) (120)
Nemotaulius hostilis (Hagen) (121)
Philarctus quaeris (Milne) (123)
Psychoglypha alascensis (Banks) (124)
Caddisflies of the Yukon 827
Psychoglypha subborealis (Banks) (125)
Phryganeidae
Agrypnia deflata (Milne) (130)
Agrypnia glacialis Hagen (131)
Agrypnia improba (Hagen) (132)
Agrypnia macdunnoughi (Milne) (133)
Agrypnia straminea Hagen (137)
Banksiola crotchi Banks (138)
Phryganea cinerea Walker (140)
Ptilostomis semifasciata (Say) (141)
Uenoidae
Neothremma didactyla Ross (142)
Oligophlebodes ruthae Ross (143)
Oligophlebodes sierra Ross (144)
Oligophlebodes zelti Nimmo (145)
These Nearctic Trichoptera from glacial refuges to the south are of 2 broad groups—
western montane species and transcontinental species. The western montane species are
mainly members of the Spicipalpia and Annulipalpia whose larvae live in lotic habitats
characteristic of mountainous terrain. This group is particularly diverse southward through
Oregon to California and Colorado, but markedly less successful to the north (Table 1
below): Glossosomatidae, Rhyacophilidae, Hydropsychidae, Philopotamidae, Polycentropodidae,
Brachycentridae (Micrasema), Lepidostomatidae, Limnephilidae (Chyranda,
Discosmoecus, Ecclisomyia, Psychoglypha), and Uenoidae. Figures for declining species
diversity at higher latitudes (Table 1) indicate that the lotic species of the western montane
Trichoptera have populated the glaciated terrain of the Yukon with limited success. Lentic
species of western montane origin in a few genera of the Limnephilidae (Asynarchus,
Clistoronia, Lenarchus, Limnephilus) and the Leptoceridae (Mystacides, Ylodes) have
extended farther north in the Yukon than have the lotic species of montane origin.
Transcontinental species are inferred to have passed glaciation along a much wider ice
front because overall they are now widely distributed in North America. They are, for the
most part, species of lentic waters and slowly moving streams. These species are primarily
case-makers of the Integripalpia; their diversity also declines with increasing latitude
(Table 1), but not as much as in the Spicipalpia and Annulipalpia where most species live
in lotic waters. Transcontinental Trichoptera occur to a large extent across the boreal forest
biome but their lake and marsh habitats also extend through deciduous forests and grasslands.
Larvae of these species, and of Trichoptera generally, have little or no specific relationship
with vascular plants, and feed for the most part on the fungi colonizing plant detritus and on
algae, or on other insects. In general, the effect of low temperature on aquatic habitats seems
to be the major constraint to repopulation of the Yukon by species in both groups of Category
I Trichoptera; this topic is explored further under Ecological Considerations.
There is an interesting recurrence in northern Quebec of disjunct populations of several
species which otherwise appear to be confined to western or northwestern North America
(Roy and Harper 1979; Harper 1989): Arctopsyche grandis (23) (Hydropsychidae), Wormaldia
gabriella (33) (Philopotamidae), and Goera tungusensis (47) (Goeridae). The first
2 are Nearctic species (category I) which probably passed the Wisconsinan glaciation south
of the ice, and now range broadly in western montane areas from the Yukon southward.
Goera tungusensis is Holarctic (category II) and may also have passed the last glacial period