EVALUATION ON THE ACTIVITY AND EFFICACY OF OMNIPRENE 20CS AGAINST AEDES, ANOPHELES AND CULEX MOSQUITOES IN OUTDOOR MICROCOSMS

Abstract

Mosquito control by pesticides remains the main intervention to reduce the burden of mosquito nuisance and mosquito-borne diseases. In mosquito control, larviciding by application of environmentally friendly larvicides has been one of the routine operations. Larvicides based on microbial agents and insect growth regulators (IGRs) account for most of the available products. Ones that are formulated using S-methoprene ranged from microencapsulated concentrate (or capsule suspension - CS), various granules, and pellets to briquets for different habitats. The CS formulation has been among the traditional products based on S-methoprene due to its advantages of easy application, fast action, and even area coverage. The current paper evaluated a newly developed CS formulation OmniPrene 20CS^TM containing 20% S-methoprene against mosquitoes of public health importance. High inhibition of emergence activity was indicated against the test species, and Aedes and Anopheles mosquitoes showed higher susceptibility than Culex in laboratory bioassays. The performance under field conditions exceeded the label specification of the currently available products with the same application pattern. Over the 21-day evaluation period, the control levels ranged 86.4-100%, 89.8-100% and 79.8-100% against Aedes aegypti, Anopheles hermsi and Culex quinquefasciatus respectively when it was applied at the intended label dose of 54.8-73.1 mL/ha. This product is expected to be used as one of the viable tools along with other available products to combat mosquitoes of public health concerns.