Oviposition behaviour of Aedes albopictus in temephos and Bacillus thuringiensis israelensis-treated ovitraps

• Main Authors: Nazni, W.A., Lee, H.L., Wan Rozita, W.M., Lian, A.C., Chen, C.D., Azahari, A.H., Sadiyah, I.
• Format: Article
• Published: 2009
• Subjects: QH301 Biology
• Online Access: http://eprints.um.edu.my/8496/

This study was conducted to determine the response of dengue vectors to ovitraps treated with temephos and Bacillus thuringensis israelensis (Bti) compared with untreated ovitraps which only contained seasoned tap water. The study was conducted at two sites: the natural breeding habitats where the ovitraps were exposed directly to sunshine and rain, and under shelter beneath a cabin without direct exposure. The ovitraps were placed for a period of five days at six different sites each in both conditions. The experiments were replicated three times. The results indicated that all mosquitoes breeding in the ovitraps were Aedes albopictus. There was no significant difference in the ovipositioning behaviour in the natural habitat, but there was a significant difference in the number of eggs laid in the ovitraps placed under the cabins. Though the mean number of eggs laid in traps in response to each treatment varied among the sites, the overall ovipositioning activity was not significantly different between sites when egg densities in the test ovitraps were averaged over the six-week ovitrapping period (site versus treatment effect) at p<0.05. The study also indicated that there was no ovicidal effect of both control agents since hatching of eggs occurred. Although eggs hatched, all larvae died eventually. The male to female ratio was 1:1 for both the sites. The study also showed that larval index is as effective as pupal index and can be used as a surveillance tool for the dengue vectors. It is concluded that containers treated with larvicide are not repellent to Aedes.