"SHORT-HORNED" BUGS
(HOMOPTERA: AUCHENORRHYNCHA)

K.G.A. Hamilton

FAUNAL COMPOSITION

This analysis of the diversity of "short-horned" bugs in the Montane Cordilleran Ecoregion (MCE) of inland British Columbia and the mountains of Alberta is based on years of insect surveys documented in the collections of the Canadian National Collection of Insects, Ottawa, Ont. and the University of British Coumbia, Vancouver. Bugs have been well sampled in Canada and the northern USA over the last half century, beginning with the Northern Insect Survey in the 1950s. Major collecting gaps include the inland area of northern Québec, northern Saskatchewan and the boreal and montane areas of mainland British Columbia west of the Frazer River (including Ecoregions 198-202 of MCE). The rest of MCE is well sampled compared to much of the rest of Canada, particularly at low elevations where road access is easy. Bogs and subalpine meadows are habitats that probably will yield additions to the MCE bug fauna.

Probably over 1500 species of "short-horned" bugs inhabit Canada. This is less than 3% of the total estimated insect fauna of Canada (Danks 1979). Other bugs are estimated to have more than 2500 species in Canada, but half of these are aphids (Aphidoidea) and plant bugs (Miridae) with perhaps only about 50% of the species known. Fully 93% of the "short-horned" bug fauna in adjacent states of the U.S.A. has been recorded from Canada, indicating a well-studied Canadian fauna.

In MCE the "short-horned" bug fauna is represented by 10 families and 123 genera containing 483 species. The 2 largest families of this fauna are leafhoppers (398 species) and delphacid planthoppers (37 species). The remaining 8 families are represented by just 48 species in total: Cixiidae (9), Cercopidae (7), Achilidae (7), Membracidae (7), Cicadidae (6), Clastopteridae (6), Fulgoridae (3), Caliscelidae (2) and Derbidae (1). Most have 25%-40% of their Canadian fauna in the MCE. This proportion falls to only 4% in treehoppers and 6% in derbid planthoppers, two families which are best represented in North America by their eastern faunas of hardwood forests. By contrast, 60% of the Canadian fauna of achilid planthoppers is found in the MCE. Canadian achilids are mostly widespread insects associated with softwood forests.