Fear vs feeding: Disentangling the consumptive and non-consumptive effects of Lutzia fuscana on Anopheles stephensi for biocontrol approach

Abstract

The vector mosquito, Anopheles stephensi Liston, 1901, transmits malaria-causing parasites and leads to millions of human deaths globally, which calls for effective management strategies. Traditional management strategies often rely heavily on chemical insecticides, resulting in insecticide resistance in mosquitoes. In this context, this study explores the efficiency of Lutzia fuscana Wiedemann, 1820 larvae as a biological control agent of An. stephensi in the larval habitats. The predation efficiency (consumptive effect) of Lz. fuscana on An. stephensi, along with the non-consumptive effects (NCEs) on An. stephensi life history traits were examined under laboratory conditions. Additionally, the oviposition behaviour of An. stephensi was observed in the presence of Lz. fuscana cues and larvae. The results exhibited that Lz. fuscana larva consumed ∼21 An. stephensi larvae day⁻¹ with ∼62 min of handling time, as estimated by the type II functional response curve. The NCEs of Lz. fuscana on An. stephensi were mostly positive, as the age at pupation decreased, and the pupal weight, adult dry weight and wing length increased more than the control in the presence of predator cues, caged Lz. fuscana, and conspecific kill. Conversely, An. stephensi laid significantly lower eggs in the presence of predator cues and Lz. fuscana. Therefore, Lz. fuscana can be utilized as a potential biological control agent against An. stephensi in the larval habitats. The findings of this study are expected to deepen our understanding of both consumptive and non-consumptive effects of predators on mosquitoes, offering insights that could enhance mosquito control strategies.