Mortality Rate of House Flies (Diptera: Muscidae) Exposed to Insecticidal Granular Fly Baits Containing Indoxacarb, Dinotefuran, or Cyantraniliprole

Abstract

The mortality rate of a field population of house fly (Musca domestica L.) was determined for a granular fly bait containing the active ingredient indoxacarb, which was compared to two commercially available granular fly baits containing either dinotefuran or cyantraniliprole. Indoxacarb was applied at three different application rates 0.498, 0.986, and 1.972 g/m2 (low, medium, and high). Time to 50% mortality was fastest for dinotefuran (5.7 h) and slowest for the low application rate of indoxacarb (10.3 h). Time to 90% mortality was fastest for the high application rate of indoxacarb (27.7 h) and slowest for dinotefuran (51.0 h) and cyantraniliprole (45.9 h). Among the three indoxacarb application rates, the high rate reached both 50 and 90% fly mortality significantly faster than the low rate. The medium rate did not significantly differ from either the high or low application rates. Dinotefuran bait produced greater fly mortality than all other treatments at 30-min post-exposure, with mortality for remaining baits exceeding controls by 3- to 6-h post-exposure. All insecticidal baits produced similar fly mortality by 6-h post-exposure and >94% fly mortality by 96-h post-exposure, indicating that each may be effective in a fly management program. Flies consumed a similar amount of the indoxacarb (regardless of application rate) and dinotefuran baits, but consumed less of the cyantraniliprole bait, suggesting a feeding irritancy or toxicity effect manifested during consumption. Nevertheless, flies consumed enough cyantraniliprole bait to cause mortality similar to other baits by 6-h post-exposure.

Keywords: application rate; bait consumption; granular bait; insecticide; time-response mortality.