Lethal and sublethal effects of insecticides and essential oils on the biological, reproductive, and behavioral traits of the hoverflies Allograpta exotica.
Serphidae, side effects, aphids
Hoverflies are important pollinators of flowering plants in many ecosystems worldwide. Insect pests, including aphids, cause a lot of damage to different crops and the use of insecticides is a frequent tool of their control. The hoverfly insectivore larvae are natural predators of aphids, thrips, and other plant-sucking insects and play a crucial role in regulating pest populations in agriculture. However, the use of insecticides can have lethal or even sublethal effects on these beneficial insects, essentially affecting their feeding behavior and their effectiveness in controlling aphids. This study aims to evaluate the Lethal and sublethal effects of synthetic and plant-based insecticides on the hoverfly's, Allograpta exotica, biological, reproductive, and behavioral traits. The study will be carried out in the Molecular Entomology and Ecotoxicology laboratory (MEET) at the Universidade Federal de Lavras. The toxicological bioassays will consist of exposing the hoverflies A. exotica larvae and adults to variable doses of insecticides commonly used in vegetable crops and essential oils (EOs) with the potential of use in pest insect control. The mortalities caused by the insecticides will be evaluated after 24-48 hours and the concentration-response curves will be determined for each insecticide and EO. Subsequently, the sublethal effects on the predatory capacity of the larval stage of A. exotica will be assessed. Groups of fifty L2 and L3 larvae will be exposed to the sublethal concentrations LC0, LC1, LC5, LC10, and LC20 andeach larvae will be offered 20-40 aphid nymphs to assess their predatory capacity. Finally, the fecundity and fertility of adults emerging from sublethally exposed larvae will be investigated. The gained knowledge from the present work will provide valuable information on the interactions between hoverflies and insecticides that could be used for better implantation of integrated pest management (IPM) strategies for aphids.