a1 Entomology Research Institute, Canada Department of Agriculture, Ottawa, Ontario and Department of Biology, University of Waterloo, Waterloo, Ontario
Sex ratios at emergence of Aedes impiger and A. nigripes in the Hazen Camp area (81°49′ N., 71°18′ W.), northern Ellesmere Island, N.W.T., are given from trap records, mainly for 1963.
There is a marked predominance of females in trap catches from temporary ponds, and an overall slight predominance of females (but with marked pond-to-pond variation) in permanent ponds. The nature of these inter-pond differences favours the inference that, before emergence, males normally survive less well than females, especially under the conditions existing in temporary ponds as they dry up.
(Received February 01 1973)
p1 Present address: Department of Entomology, North Carolina State University, Raleigh, N.C., U.S.A.
p2 Present address: Department of Biology, University of Waterloo, Waterloo, Ont., Canada.