How effective are Mesocyclops aspericornis (Copepoda: Cyclopoida) in controlling mosquito immatures in the environment with an application of phytochemicals?

Abstract

We investigated the susceptibility of Mesocyclops aspericornis and Aedes aegypti larvae to mosquito larvicidal phytochemicals: piperine and eugenol and the predation efficiency of the adult female M. aspericornis on Ae. aegypti larval instar-I and late II at the sublethal concentration of piperine and eugenol. Both prey and predator were susceptible to both the phytochemicals; however, the lethal concentration of either phytochemicals recorded for Ae. aegypti did not exert mortality on the copepods. The predator’s latent time was significantly longer in the phytochemical medium than control. The encounter frequency was significantly higher in control than in the phytochemical medium. For instar-I larvae, the post-encounter attack probabilities were not affected by the tested phytochemicals. However, for instar-II, the post-encounter attack probability was lower in eugenol treatment than in either the control or piperine. The escape and post-escape survival probabilities of larvae were substantially lower in phytochemical treatments than in the control. However, the overall copepod-imposed mortality did not differ significantly between the control and the phytochemical medium. In conclusion, both the phytochemicals modify the copepod feeding behavior without affecting the copepod incurred total larval mortality. Therefore, application of these phytochemicals along with M. aspericornis for mosquito control is advisable.