Control of DF/DHF Vector, Aedes Mosquito, with Insecticides

Abstract

Aedes aegypti, the principal vector of DF/DHF, mainly breeds in household water jars. The breeding sites are definite and, thus, the larviciding will become the most effective measures as well as source reduction. However, the following facts make it difficult. 1) Water in the jars is used and refilled. The replenishment of water leads to dilution of larvicides. 2) Many small breeding sites are overlooked, such as water at the bottom of household plant pots. To solve these problems, two new larval control methods were examined. The first was the slow release formulation containing the insect growth regulator, pyriproxyfen, which highly inhibited adult emergence of mosquitoes. The formulation kept concentration enough to inhibit adult emergence, even after replacing water in the container. The second was the utilization of blood-fed females as a vehicle of pyriproxyfen to small larval habitats. When the black-color adult resting traps treated with pyriproxyfen were kept inside a house, it was confirmed that the mosquitoes contacted with pyriproxyfen and carried it to small containers with water. Permethrin-incorporated bednet was introduced as a tool for preventing of further virus dispersion from patients by mosquito bitings. Momentary contact of the females with the netting resulted in high mortality. However, early diagnosis method of patients will be essential. For a self-protection, inhibitory effect of a mosquito coil on host-seeking behaviour of Aedes aegypti was demonstrated.