Predator selection and predator-prey interactions for the biological control of mosquito dengue vectors in northern Vietnam.

Predators and their interactions with target prey influence the efficiency of control strategies. In the present study, we demonstrate the implementation of natural predator selection for controlling dengue vectors in northern Vietnam through field-based observation of aquatic insect predators in natural habitats and lab-based assessment of predatorial capacities for several aquatic insect predators. The selected species was then used to evaluate the predatory-prey interaction using functional responses (FRs) toward 3- and 4-instar larvae of four major medical mosquito species (, and ). The preference of selected predators for larvae over other mosquito larvae was also investigated. Both field observation and lab experiments indicated that the giant water bug was abundant and exhibited the highest predatory capacity for mosquito larvae. The predator exhibited type II FRs when offered each of the four prey species, and the greatest attack rates were observed for and , with only negligible differences observed in the handling times of the prey species. Further, Manly's selectivity (α) values calculated from the prey choice experiments showed that was preferred over both and . Together, these findings indicate that could be successfully used to facilitate the biological control of both and within the species' distributional overlap in Southeast Asia.