Beecomist-applied Bacillus sphaericus for the control of riceland mosquitoes

An aerially applied flowable concentrate (FC) of Bacillus sphaericus Neide (isolate 2362) was evaluated against riceland mosquitoes using the Beecomist spray head. Application of the FC at 0.58 and 1.17 liter/ha in maturing rice fields resulted in a 48 hr mean posttreatment reduction of Anopheles quadrimaculatus of 71 and 82%, respectively. A significant reduction in larval populations one week posttreatment was also observed. Treatment rates of 0.29, 0.44, and 0.58 liter/ha in reflooded second crop rice fields resulted in 48 hr posttreatment reduction of Psorophora columbiae larvae of 50, 76 and 98% respectively.