Sumba Leunita A, Ogbunugafor C Brandon, Deng Arop L, Hassanali Ahmed
International Centre of Insect Physiology and Ecology (ICIPE), P.O. Box 30772-00100, Nairobi, Kenya.
J Chem Ecol. 2008 Nov;34(11):1430-6. doi: 10.1007/s10886-008-9549-5. Epub 2008 Oct 16.
Females of Anopheles gambiae Giles normally oviposit in a large number of fresh, small, sunlit, and spatially spread temporary pools. Such pools are associated with lower levels of predation compared to large, longer-lasting habitats. We compared oviposition levels on preferred (water collected from natural anopheline larval habitats) and non-preferred (distilled water) aqueous substrates by gravid females that contained different densities of conspecific eggs or early and late instar larvae. The presence of conspecific larvae, but not eggs, had a positive or negative effect on the ovipositional responses of gravid An. gambiae females, depending on the quality (preferred or non-preferred by the mosquito) of the oviposition water and the density of larvae. Presence of larvae, at all densities, in distilled water deterred oviposition. However, in natural anopheline pool water, a low density of larvae increased oviposition, whereas a higher density inhibited oviposition. Our results suggest that two signals produced by this mosquito may be involved in regulating oviposition: a volatile pheromone emitted by conspecific larvae, which augments the effect of a volatile signal emitted by preferred habitats, and a non-olfactory cue associated with high densities of larvae that deters oviposition.
冈比亚按蚊（Anopheles gambiae Giles）雌蚊通常会在大量新鲜、小型、有阳光照射且分布分散的临时水塘中产卵。与大型、持久性更强的栖息地相比，这类水塘中的捕食水平较低。我们比较了怀有不同密度同种卵或不同龄期幼虫（早期和晚期）的妊娠雌蚊在偏好性（从天然按蚊幼虫栖息地采集的水）和非偏好性（蒸馏水）水性底物上的产卵水平。同种幼虫而非卵的存在，对妊娠冈比亚按蚊雌蚊的产卵反应有正向或负向影响，这取决于产卵水的质量（蚊子偏好或不偏好）和幼虫密度。在蒸馏水中，无论幼虫密度如何，其存在都会抑制产卵。然而，在天然按蚊水塘水中，低密度幼虫会增加产卵量，而高密度幼虫则会抑制产卵。我们的结果表明，这种蚊子产生的两种信号可能参与调节产卵：一种是同种幼虫释放的挥发性信息素，它增强了偏好栖息地释放的挥发性信号的作用；另一种是与高密度幼虫相关的非嗅觉线索，它会抑制产卵。
