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The effect of controlled burning on the survival of Aedes mosquito eggs was evaluated in 2 distinct dambo habitats. In a dambo dominated by grasses, egg survival was 3.3% after burning compared with 43.8% in a similar dambo that was not burned. In a dambo dominated by sedges, egg survival was 0.7% after burning compared with 28.5% in a similar dambo that was not burned. Mortality of mosquito eggs appeared to be caused by high temperatures associated with the fire and not elapsed time since egg survival did not decrease with time after burning. The potential for burning to control the mosquito vectors of Rift Valley fever virus is discussed.

Effectiveness of sustained-release Altosid pellets (4% AI methoprene) against floodwater mosquitoes in dambos treated at 5, 3, and 1 wk before and 1 day after flooding was determined. Only 2% of Aedes pupae (primarily Aedes mcintoshi) survived to adults in an area treated 5 wk preflood, and no adult mosquitoes emerged from an area treated 1 day after flooding. In contrast, 12 and 16% of Aedes pupae successfully survived to the adult stage in areas pretreated 3 and 1 wk, respectively, preflood. The effectiveness of the Altosid declined against Culex spp. (primarily Cx. antennatus) collected from dambos 15-31 days after flooding. The potential for using preflood treatment with methoprene to control Aedes vectors of Rift Valley fever virus in endemic areas is discussed.