Assessment of Various Colors Combined with Insecticides in Devising Ovitraps as Attracting and Killing Tools for Mosquitoes

Simple Summary The Aedes mosquito species are highly adapted to human dwellings where they develop in a large variety of human-made containers, and adults feed on human blood, resulting in the transmission of deadly disease agents. Therefore, the development of attracting and killing tools in the form of traps is thus required In the current studies, our primary focus was on developing low-cost monitoring tools to be exploited for the ultimate suppression & control of dengue vector mosquitoes. The attractive baited traps have shown promising results in laboratory settings and have the potential to significantly reduce the Aedes mosquito populations in the pilot field as well. Monitoring trials in the selected sites were deployed for the population fluctuation of dengue vectors and were compared with the surrounding buffer neighborhood with no traps. Entomological survey data from the study was utilized for recording the reduction in egg-laying mosquitoes in the neighborhood with traps. These traps were designed to reduce the number of mosquitoes through two main actions: (1) Attraction: Aedes species were attracted by the combination of odors emitted by baits in the water inside the trap and the black color of the trap; (2) Adulticide: the inside walls of the trap were lined with insecticide deltamethrin that kills resting adults. Abstract Dengue virus, transmitted by Aedes aegypti mosquitoes, is the most important emerging viral disease, infecting more than 50 million people annually. Currently used sticky traps are useful tools for monitoring and controlling Ae. aegypti. Therefore, this study was conducted to evaluate the attraction of Ae. aegypti mosquitoes using various colors, materials and insecticides. The laboratory and field assessed the four different colors of ovitraps (blue, green, black and transparent). Among the tested ovitraps, the black ovitraps showed the highest number of eggs (348.8) in the laboratory and maximum eggs (80.0) in field trials. In addition, six different materials (casein, urea, yeast, fish meal, chicken meal and water) were also used to evaluate mosquito’s attraction. In our results, the highest number of eggs were collected with fish meal having 0.5% concentration in both laboratory (195.17) and the field (100.7). In laboratory trials, the Deltamethrin treated ovitraps (treated with Deltamethrin) significantly trapped and killed the highest percent of female Ae. aegypti (91.5%) compared to untreated (not-treated with Deltamethrin) ovitraps (3.3%). In field trials, the lethality was determined by installing 10 lethal ovitraps in one block and 10 untreated ovitraps in another block. The results indicate a significant reduction in eggs collected from the treated block (727 eggs) as compared to the untreated block (1865 eggs). The data also reveal that the ovitrap positive index (50) and egg density index (24.3) were also low in treated areas than in untreated areas, 83.3 and 37.3, respectively. It is concluded that the lethal ovitraps significantly reduced the Ae. aegypti population and thus could be considered an integral part of the integrated vector management (IVM) program.