Evaluation of lethal ovitraps as a strategy for Aedes aegypti control

Abstract

Introduction: Dengue fever is a vector-borne viral disease of major public health importance. In the absence of a vaccine, control measures are primarily focused on reducing the mosquito vector. However, these strategies are very expensive, and the use of lethal ovitraps could contribute, in a practical manner, to the design of cost-effective strategies for vector control.

Objective: To determine the most efficient type of lethal ovitrap for Ae. aegypti vector control by combining different types of insecticides, oviposition substrates and attractant infusions.

Materials and methods: The study was conducted in two stages. In the first, 18 different ovitraps resulting from the combination of insecticides (deltamethrin and permethrin), oviposition substrates (towel, dacron and flannel), and attractant infusion (10 and 20% hay infusion, and dechlorinated water) were evaluated in the laboratory. For this evaluation, ovitraps were placed into a mosquito holding cage, and 100 gravid Ae. aegypti females were released. The top six ovitraps were selected based on the higher number of registered eggs, and the lower hatched eggs percentage. In the second, the top six ovitraps were evaluated in field conditions.

Results: In laboratory conditions, statistical differences were observed between the 18 ovitraps. The ovitraps with deltamethrin were the most efficient showing the best results. In field conditions, the ovitraps with the highest vector reduction were those combining deltamethrin/towel/10% hay infusion.

Conclusions: The ovitrap combining deltamethrin, towel as oviposition substrate, and 10% hay infusion as attractant was the most efficient Ae. aegypti vector control.