Effect Of Chlorpyrifos On The Oviposition And Survival Of Aedes Aegypti (Diptera: Culicidae)
  Key Words  
  Fitness cost, fecundity, selection, trade-off, dengue
  Lee-Jin Bong and Wu-Chun Tu
  Phenomenal of high egg reproduction when mortality risk rose is very common in mosquito. Yet, the presence of this reproduction advantage in insecticide resistance mosquito remains unclear. In this study, we evaluated the effect of chlorpyrifos (CP) exposure on the oviposition and survival of Aedes aegypti using two strains. We found that CP exhibited no oviposition deterrent against female mosquitoes of both Lab and KH strains, given that the females did not show any decrease in their reproduction activity on CP-treated sites. High mortality was recorded in Lab strain after contacting the CP-treated oviposition sites on day 4. Before death, the mosquitoes oviposited large number of eggs indicating the adaptive strategy of the mosquito aimed at maintaining the progeny in the population. However, this reproductive effort was not seen in KH strain although ~60% of the mosquitoes were killed at 1.0 ppm CP. Mosquitoes of this strain are exposed to a variety of insecticide. Coping with the toxicity of insecticides can be costly, and thus energy and resource are redirected to survival instead of reproduction.