The potential of the Beauveria bassiana MHK isolate for mosquito larval control

Abstract

The African malaria mosquito, Anopheles gambiae Giles (Diptera: Culicidae), and the Asian tiger mosquito, Aedes albopictus Skuse (Diptera: Culicidae) are of public health concern due to their ability to transmit disease-causing parasites and pathogens. Current mosquito control strategies to prevent vector-borne diseases rely mainly on the use of chemicals. However, insecticide resistance in mosquito populations necessitates alternative control measures, including biologicals such as entomopathogenic fungi. Here we report the impact of a Beauveria bassiana (Balsamo) Vuillemin (Hyprocreales: Cordycipitaeceae) isolate, MHK, isolated from field-collected Ae. albopictus larvae on mosquito survival and development. Larval infection bioassays using three B. bassiana conidial doses were performed on the second and third larval instars of An. gambiae and Ae. albopictus mosquitoes. Larvae were monitored daily for survival and development to pupae and adults. Our results show that B. bassiana MHK was more effective in killing An. gambiae than Ae. albopictus larvae. We further observed delays in development to pupae and adults in both mosquito species exposed the varying doses of B. bassiana as compared to the water control. In addition, larval exposure to B. bassiana reduced adult male and female survival in both mosquito species, further contributing to mosquito population control. Thus, this study identifies the locally isolated fungus, B. bassiana MHK, as a possible biological control agent of two mosquito species of public health concern, increasing the arsenal for integrated mosquito control.