Life history traits and predatory performance of Belostoma anurum (Hemiptera: Belostomatidae), a biological control agent of disease vector mosquitoes

Abstract

Understanding the life cycle and dietary requirements of laboratory-reared insects is critical for optimizing resources (including time) and can provide more reliable ecological basis for using such biological control agents in realistic programs. Here, we evaluated the complete development and the predatory abilities of Belostoma anurum (Herrich-Schäffer, 1848) (Hemiptera: Belostomatidae), an aquatic predator widely distributed in Neotropical region, when reared at different diets. We firstly investigated the predatory performance of B. anurum nymphs upon mosquito larvae (i.e., larvae of Aedes aegypti (Linnaeus, 1758) or Culex sp. (Diptera: Culicidae)) and, second, whether the immature diets (i.e., arthropodbased diet (mosquito larvae and adults of Notonectidae) or vertebrate (fish larvae)–based diet) affect the predatory behavior of B. anurum adults. The B. anurum egg-to-adult developmental time was 85.1 days in an arthropodbased diet. However, when a fish-based diet was offered after nymphs reached 3rd instar, we recorded up to 50% reductions on the B. anurum developmental time. Interestingly, B. anurum adults could live more than 1 year under laboratory conditions, independently of the immature diet regime. Furthermore, the fish diet–experienced B. anurum adults spent less time feeding on fish larvae when compared with adults that never experienced this type of diet. Predatory results revealed that 2nd instar B. anurum were more efficient to catch and consume larvae of A. aegypti than of Culex sp. Collectively, our findings show that B. anurum is long-lived aquatic predators, and demonstrate the impacts of dietary regime on the life history traits and predatory performance of these insects.