288 - Using amber bottles for naled bioassays

Abstract: Bottle bioassays are commonly used to detect resistance to pesticides by mosquitoes. Naled is a chemical pesticide frequently used as an adulticide by mosquito control operations. Bottle bioassays with naled are difficult to conduct because of the short half-life of naled, as it is quickly degraded by light and humidity. Bottle bioassays were conducted with amber glass and flint glass bottles. A colony of Aedes aegypti was assayed at 0, 3, 6, and 24 hours post bottle preparation. Bottles were continuously exposed to fluorescent light or sunlight during the assays. Some bottles had caps removed between assays whereas other bottles remained capped. The type of glass had an effect on pesticide performance over time but whether the caps were left on or removed was also important. There appeared to be an interaction between effect of glass type and use of caps on the bottles. The effect of type of light was a factor as well.