The effect of Bacillus sphaericus upon the susceptibility of Anopheles quadrimaculatus to Plasmodium berghei.

Larvae of Anopheles quadrimaculatus were exposed to Bacillus sphaericus. The surviving adults took blood meals on hamsters infected with Plasmodium berghei. Fewer mosquitoes were infected than were the paired controls. The inhibitory action appeared to occur during the early stages of the infection in the mosquito gut.