Structural and functional composition of the community of Chironomidae (Diptera) in a Canadian Shield stream

Publisher Website
Google Scholar
Abstract
The chironomid community of Canisbay Creek, a Shield region stream flowing in Algonquin Park, Ontario, revealed substantial differences in species structure and emergence phenology to that previously described for the community of a spring-fed wooded stream in southern Ontario. These differences are attributed to the different chemical and thermal regimes in the two streams. Weekly samples were taken from anchored floating emergence traps. Of the 72 species found, 15 are undescribed. Most were either Orthocladiinae or Tanytarsini; no Diamesinae were recorded. Both univoltine and multivoltine species occurred and some of the latter became asynchronous during spring and summer. Absolute temperatures and daily thermal divergence played important parts in emergence cueing. The Chironomidae are shown to be active components in the ecosystem throughout the year, and it is argued that the season of larval growth, along with relative body size, should be considered in the functional classification of the species in this group.