A novel method of controlling a dengue mosquito vector, Aedes aegypti (Diptera: Culicidae) using an aquatic mosquito predator, Diplonychus indicus (Hemiptera: Belostomatidae) in tyres

ABSTRACT

An investigation was undertaken to evaluate the biocontrol potential of a mosquito predator, Diplonychus indicus, against the immatures of dengue vectors breeding in used tyres. Two gardens were selected and ten tyres each filled with water were kept in different sites of both gardens. One was considered as “control” where no predator was used, whereas in the tyres kept in the “experimental” garden, two second instars of D. indicus were released into each tyre. The absolute density of larvae, pupae and man-landing rate of dengue vector were monitored at weekly intervals. After one year, the predators released in the tyres in the experimental garden were removed and it became the control garden whereas two second instars predators were released into the tyres kept in the control garden which then became the experimental garden. When D. indicus was introduced into the tyres kept in the experimental garden, a drastic reduction of 95% and 98% respectively of late instars and pupae of Ae. aegypti was observed. But there was no reduction in the tyres kept in the control garden. The density of early instars of Ae. aegypti fluctuated in the tyres kept in both the gardens during different months of the year. There were significant differences between the densities of early, late instars and pupae of Ae. aegypti in experimental and control gardens (early p