The influence of a light and dark cycle on the egg laying activity of Aedes aegypti (Linnaeus, 1762) (Diptera: Culicidae)

BACKGROUND The epidemiological importance of the mosquito Aedes aegypti as a vector of multiple human pathogens has generated a growing number of studies on the physiology and behaviour of its blood-feeding females. The activity of oviposition is one of the critical elements contributing to the expansion of Ae. aegypti's populations. Although there is a vast literature about oviposition behaviour, significant specific knowledge about egg viability and female fertility under light and dark conditions is still lacking. OBJECTIVES We studied, in controlled laboratory conditions, the effect that light and dark cycles have on the efficiency of oviposition by Ae. aegypti females. METHODS Physiological assays were performed using synchronised eggs obtained from forced egg laying. The number and viability of eggs was analysed under three different light/dark regimes: LD12:12 (12 h of light and 12 h of dark), DD (constant darkness) and LL (constant light). FINDINGS and CONCLUSIONS Our results show that females prefer to lay their eggs in dark conditions, but maximising the number and viability of eggs requires the occurrence of a light/dark cycle. Ongoing research on this theme has the potential of contributing to the proposition of new strategies for control based on the failure of egg laying and hatching.

研究背景
埃及伊蚊（Aedes aegypti）作为多种人类病原体的传播媒介，其流行病学重要性日益凸显，因此针对其吸血雌蚊的生理与行为开展的研究与日俱增。产卵活动是推动埃及伊蚊种群扩张的关键因素之一。尽管已有大量关于产卵行为的研究文献，但关于明暗条件下虫卵存活率与雌蚊繁殖力的针对性专业认知仍存在显著缺口。
研究目标
本研究在可控实验室条件下，探究明暗周期对埃及伊蚊雌蚊产卵效率的影响。
研究方法
本研究采用人工强制产卵获得的同步化虫卵开展生理实验，针对三种不同明暗光照制度：LD12:12（12小时光照与12小时黑暗）、DD（持续黑暗）及LL（持续光照）下的虫卵数量与存活率进行分析。
研究结果与结论
本研究结果显示，埃及伊蚊雌蚊更倾向于在黑暗环境中产卵，但要实现虫卵数量与存活率的最大化，则需要明暗周期的存在。当前针对该主题的后续研究，有望基于产卵与孵化失败机制提出全新的蚊虫防控策略。