Mating behavior and responses to sublethal concentrations of imidacloprid in the predator Cyrtorhinus lividipennis

Abstract

BACKGROUNDMating is an essential factor that governs the size of insect populations that reproduce sexually. The extensive application of insecticides has both lethal and sublethal effects on the physiology and mating behavior of insect natural enemies. The predatory bug, Cyrtorhinus lividipennis, is a natural enemy of planthopper and leafhopper populations in the rice ecosystem. Unfortunately, the effects of insecticides on the mating behavior of C. lividipennis are not well understood.RESULTSThe mating behavior of C. livdipennis consisted of mounting, antennal touch and mating attempts, genital insertion, adjustment of posture, and separation of the mating pair. Approximately 82.5% of the C. lividipennis mating pairs displayed their first mating at 12–36 h after emergence. Mating activity occurred throughout a 24‐h period, with peak activity at 12:00–14:00 h, and the mean duration of mating was 48.75 min. Sublethal exposure to imidacloprid increased of mating latency. Compared with the controls, the duration of courtship, pre‐mating, and adjusting posture for males treated with imidacloprid were prolonged. The duration of mating for females treated with imidacloprid was prolonged relative to untreated controls. The fecundity and daily spawning capacity of females treated with imidacloprid were higher than the untreated controls.CONCLUSIONOur results provide insight into the mating process of C. lividipennis. Imidacloprid prolonged the duration of mating, which may explain the enhanced reproductive output in C. lividipennis females treated with imidacloprid. These findings will be useful in both rearing C. lividipennis and deploying this natural enemy in rice fields.This article is protected by copyright. All rights reserved.