Dieng Hamady, Satho Tomomitsu, Suradi Nur Farrahana Binti, Hakim Hafijah, Abang Fatimah, Aliasan Nur Ezzati, Miake Fumio, Zuharah Wan Fatma, Kassim Nur Faeza A, Majid Abdul Hafiz A, Fadzly Nik, Vargas Ronald E Morales, Morales Noppawan P, Noweg Gabriel Tonga
Institute of Biodiversity and Environmental Conservation (IBEC), Universiti Malaysia Sarawak, Kuching, Kota Samarahan, Malaysia.
Faculty of Pharmaceutical Sciences, Fukuoka University, Japan.
Acta Trop. 2017 Dec;176:446-454. doi: 10.1016/j.actatropica.2017.08.033. Epub 2017 Sep 1.
In dengue vector control, attempts to minimize or replace the use of pesticides have mostly involved use of predators, but success has been severely impeded by difficulties associated with financial and environmental costs, predator mass production, and persistence in target habitats. Visual deterrents have been used successfully to control animal pests, in some cases in an effort to replace pesticide use. Despite evidence that visual signals are crucial in site choice for egg deposition by dengue vectors, and that female mosquitoes respond to artificial predation, the role of predator intimidation as it affects the oviposition behavior of dengue vectors remains largely unexplored. Here, we examined the oviposition responses of Aedes aegypti exposed to various mosquito predator pictures. Gravid females were presented with equal opportunities to oviposit in two cups with predator images [Toxorhynchites splendens-TXI, Goldfish (Carassius auratus)-small (SFI) and large (LFI) and Tx. splendens+Goldfish-TXFI] and two others without pictures. Differences in egg deposition were examined between sites with and without these images. When given a chance to oviposit in cups with and without TXI, Ae. aegypti females were similarly attracted to both sites. When provided an opportunity to oviposit in cups displaying pictures of fish (SFI or LFI) and blank cups, egg deposition rates were much lower in the fish picture sites. Females showed a preference for blank cups over TXFI for egg deposition. They also equally avoided cups with pictures of fish, regardless of the size of the picture. Our results indicate that the presence of images of goldfish and their association with Tx. larvae significantly reduced egg deposition by Ae. aegypti, and this was not the case with the predatory larvae alone. The observations that the images of natural predators can repel gravid females of a dengue vector provide novel possibilities to develop effective and inexpensive alternative tools to harmful insecticides.
在登革热病媒控制中，尽量减少或替代杀虫剂使用的尝试大多涉及使用捕食者，但由于与财政和环境成本、捕食者大规模生产以及在目标栖息地的持久性相关的困难，成效受到严重阻碍。视觉威慑物已成功用于控制动物害虫，在某些情况下是为了替代杀虫剂的使用。尽管有证据表明视觉信号在登革热病媒选择产卵地点方面至关重要，而且雌蚊会对人工捕食做出反应，但捕食者威慑对登革热病媒产卵行为的影响在很大程度上仍未得到探索。在此，我们研究了暴露于各种蚊虫捕食者图片下埃及伊蚊的产卵反应。将怀有身孕的雌蚊置于有捕食者图像（华丽巨蚊 - TXI、金鱼（鲫鱼） - 小（SFI）和大（LFI）以及华丽巨蚊 + 金鱼 - TXFI）的两个杯子和另外两个没有图片的杯子中，给予它们平等的产卵机会。检查有无这些图像的地点之间的产卵差异。当有机会在有和没有TXI的杯子中产卵时，埃及伊蚊雌蚊对这两个地点的吸引力相似。当有机会在展示鱼类图片（SFI或LFI）的杯子和空白杯子中产卵时，鱼类图片所在地点的产卵率要低得多。雌蚊在产卵时更倾向于空白杯子而非TXFI。它们也同样避开有鱼类图片的杯子，无论图片大小如何。我们的结果表明，金鱼的图像及其与华丽巨蚊幼虫的关联显著降低了埃及伊蚊的产卵量，而单独的捕食性幼虫则没有这种情况。天然捕食者的图像能够驱赶登革热病媒的怀有身孕雌蚊这一观察结果为开发有效且廉价的有害杀虫剂替代工具提供了新的可能性。
