With increased public awareness of mosquito-borne threats, pest control operators are offering mosquito control services by applying adulticides to residential daytime resting sites. We evaluated the efficacy of this technique at Kentucky residences.

A randomized complete block design was used to compare two specific adulticides, bifenthrin and lambda-cyhalothrin, as “backyard” mosquito control products. Three homes in each of eight neighborhoods (the blocking factor) were randomly assigned a water control or one of the chemicals at the maximum label rate (0.1% for lambda-cyhalothrin and 0.08% for bifenthrin). Treatments were applied with a mist blower, directed to perimeter vegetation shorter than 2m, and foliage wetted to just before runoff. Mosquito populations were sampled using landing rates, CO2 traps, gravid traps, sweep nets, and ovitraps. Sampling was conducted weekly until treatment effects dissipated. In addition to monitoring mosquito populations, treatment effects were evaluated with laboratory bioassays. Laboratory reared mosquitoes were exposed to treated leaves (collected from the properties) in a no-choice test. Finally, homeowners completed three surveys designed to assess their attitudes towards treatment effectiveness.

Both products significantly reduced mosquito populations however; the lambda cyhalothrin formulation had longer residual effectiveness. Initially, all mosquito species were equally suppressed, but post treatment differences between Culex and Aedes species developed over time. Questing and gravid mosquitoes were not equally suppressed suggesting this technique should be combined with a broader management program. Results from homeowner surveys are also presented.