LIFE-HISTORY OF CRICOTOPUS-MYRIOPHYLLI OLIVER (DIPTERA, CHIRONOMIDAE)IN THE OKANAGAN VALLEY, BRITISH-COLUMBIA

The life history of Cricotopus myriophylli Oliver is described from bo th field observations and laboratory rearing of field-collected larvae . The species appears to be univoltine with four larval instars and ha s a sex ratio of ca. 2:1, males to females. Emergence begins in late M ay in British Columbia and continues until mid-September, with first-i nstar larvae present in the field from mid-June to mid-August. Water t emperature does not appear to influence the rate of emergence. In the laboratory at 21 degrees C, larvae complete each of the third and four th instars in 10-14 days. Cricotopus myriophylli overwinters primarily in the third larval instar, although second and fourth instars were a lso recovered in field-collected samples. First-instar larvae and eggs were not recovered from winter samples. This species does not appear to undergo a true diapause.