In 1976 and 1977, adults of Aedes sticticus (Meigen) and Aedes vexans (Meigen), marked with fluorescent dust, were captured in light traps up to 33 days after release and at distances up to 11 km from the release site. Adults flew primarily northwest from the release sites, and with the prevailing winds. Porcine and bovine hosts present at some of the trapping sites, appeared to be highly attractive to female mosquitoes. Within an 8 km trapping radius of the release site, the mean number of marked/trapped female mosquitoes decreased with distance. In 1977, 50% of the marked captures (weighted according to km2 of trapping area) were taken within the first 2 km, 82% within 4 km, 92% within 6 km, and the remainder out to 8 km from the release site. For all trap sites, the mean recovery of marked/unmarked adults over a 33 day trapping period in 1977 was 1:1113.

Can. Ent. 99: 986-993 (1967) Development time decreased wirh each increase in rearing temperature in Aedes uexans7 A. nigrmnaculis7 and Culiseta i n m t a until the optimum survival temperature was reached. The optimum survival temperature for A. vexans was 26.S°C, for A. nigromaculis 2l0C, and for C. inoraata 21°C. Dry weight gain per hour in female larvae was greater than in male larvae in all nhree species, at all temperatures. There was a significant reduction in weight in each larval instar, pupal, and adult stage, with each 5.5% increase in rearing tem'prature. Times to larval-pupal ecdysis and pupal-adult ecdysis were the same for males and females of A. nigromculis at all developmental temperatures tested. Time to larval-pupal ecdysis and pupal-adult ecdysis in A. vexans and C. inornata occurred 1 to several days later in females, depending upon the developmental temperature. In all three species the duration of che fourth instar was longest and the specific weight gain greatest.

Diapause in Wyeomyia smithii (Coquillett) was shown to be a function of photoperiod, and independent of temperature. The critical daylength for a population from Pinawa, Man., was 15 hr light per diem. The photoperiodic cues are monitored by the early instars, with diapause being expressed in the third instar. Development is also limited by temperatures below 15 °C even when the critical daylength is exceeded.Survival at low and subzero temperatures is aided by the diapause state. However, larvae are unable to withstand extended periods of subzero temperatures, even in the diapause condition. At −5 °C, 60% mortality occurred after 8 weeks under laboratory conditions. In the field, where ground temperatures averaged −3.7 °C during the five coldest months, larval mortality averaged 45% after four winter months.Once diapause is established, larvae consume very little food. Diapause larvae appear to be as active as non-diapause larvae, and also appear to be feeding constantly. However, the amount of food ingested is negligible compared to non-diapause larvae.

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