Split-Application of Bacillus thuringiensis israelensis to Control Asian Tiger Mosquito, Aedes albopictus (Skuse) (Diptera:Culicidae) without Reducing Lettuce Head Weight in Non-Circulating Hydroponics

Abstract

Vectobac G (Bacillus thuringiensis israelensis) application at 1.08 and 0.54g/ m2 to subirrigated pot and suspended forestry tube methods of non-circulating hydroponics in an unreplicated experiment greatly reduced numbers of Asian tiger mos- quito, Aedes albopictus (Skuse) (Diptera: Culicidae), larvae and pupae compared to non-treated controls. Both Vectobac G rates, however, reduced lettuce head weight and root growth compared to the control. When the 0.54/m2 rate was applied as a split-application (0.27g/m2 applied 2 weeks apart), A. albopictus larvae and pupae were still controlled throughout the lettuce cropping cycle and lettuce head weight was not significantly affected. Therefore, the split-application of Vectobac G may be an effective strategy to control mosquitos breeding in commercialized non-circulating hydroponic lettuce operations in Hawaii.