Growth and molecular responses of Culex quinquefasciatus mosquito (Diptera: Culicidae) to quality and quantity of larval diets

Abstract

With the decreased efficacies of present mosquito control strategies, in reducing the burden of mosquito borne diseases, attention has been shifted to larval stage of these vectors. However, no effective control protocol can be developed without sound knowledge of critical aspects of the bio-ecophysiology of a vector and interplays, which bring about success of the species. This study, thus, aims at bringing into clearer perspective, the influence of quality and quantities of mosquito larval diets on rates of larval growth and accumulation of teneral reserves. To this end, conventional mosquito feeds, namely, fish feed, yeast and biscuit were analysed for proximate composition, and categorised into high (HP), moderate (MP) and low proteinous (LP) diets, respectively, using standard methods, with a ‘Control’ devoid of feed. Six (6) quantity of HP feed regimens, ranging from 0.16 through to 1.60 mg/ 100 larvae, was adopted. In both studies, approximately Day-old larvae were fed ad libitum with these diet types and quantities, and reared following standard protocols. The rates of larval growth (LGR) and teneral accumulation (LTA) were determined according to standard methods. Analyses revealed a significant effect of quantities and quality of larval diets on these entomological indices. Mosquitoes raised on HP feed had significantly higher LGR than those reared on MP and LP feeds (range = 0.0116±0.0224 to 0.0710±0.0067 mg/ day) and had significantly higher LTA for all teneral components analysed. Further, mosquitoes raised on 0.32 mg/ 100 larvae had the highest LGR, while those raised on 1.60 mg/ 100 larvae had the least, range = 0.0433±0.00329 to 0.0678±0.00304 mg/day. Similar trend was observed for LTA in these quantities of diet regimen. The results of this study revealed significant effects of quantities and quality of feed on growth and accumulation of teneral reserves in mosquitoes. This information is important, as baseline in the development of effective integrated mosquito management protocol.