Interspecific interactions between mayflies (Hexagenia ) and midges (Chironomus).

Both Hexagenia (mayfly) nymphs and Chironomus (midge) larvae live in the soft sediments of Lake Erie, showing a non-overlapping mosaic distribution. The objective of this study was to quantify the importance of interactions between Hexagenia nymphs, and larval Chironomus. The field distributions of Hexagenia nymphs and chironomid larvae were analysed to examine the co-occurance of these two taxa. Little evidence of negative interactions between these taxa were found based on these analyses. Laboratory experiments were conducted that measured survivorship and increase in body length of Hexagenia nymphs and Chironomus larvae reared individually and together to determine the strength of competition for space between these taxa. The results of the experiments did not suggest competition for space. Duration effects were tested by adding Chironomus larvae to containers of Hexagenia nymphs at different stages in the development of Hexagenia. Chironomid larvae are present in the western Lake Erie sediments when Hexagenia are depositing their embryos. Laboratory experiments were conducted to determine if Chironomus larvae consume Hexagenia embryos. (Abstract shortened by UMI.) Source: Masters Abstracts International, Volume: 41-04, page: 1011. Adviser: Lynda Corkum. Thesis (M.Sc.)--University of Windsor (Canada), 2002.