Spinosad: Efficacy and persistence against container inhabiting mosquitoes.

摘要

Small scale field trials were conducted in an urban, suburban and rural area of New Jersey using simulated larval habitats to determine efficacy and persistence of an extended release granular formulation of spinosad. The work was done under sunlit and shaded conditions. Determining mortality of invasive container-inhabiting mosquitoes of public health importance was a primary goal of this study. Plastic containers commonly found in a household setting were treated with the larvicide spinosad at the low, middle and maximum label rates (5.6, 11.2, 22.4 kg-1 ha respectively) and compared to an untreated control. Persistence of insecticidal activity measured in weeks throughout the mosquito season was evaluated with respect to relative sunlight exposure, water temperature, water pH and accumulation of organic debris. A laboratory study was performed using Aedes albopictus (Diptera: Culicidae), in the absence of spinosad treatment, to investigate potential for container induced effects on immature development.;Spinosad extended release granules at all application rates tested were an effective larval control agent against all common pest species of container-inhabiting mosquitoes in the 3 study areas tested. Larval mortality was >95% in treated containers and persisted at or beyond labeled periods for all treatments. Increasing application rate (total a.i. per unit area) was positively correlated with persistence of insecticidal activity. Mean larval habitat water temperature did not differ significantly with respect to light conditions over the course of the season. Dominant cover vegetation available, exposure to direct sunlight and larval habitat water pH are factors to be considered on a site specific basis with respect to spinosad application rates. Under standard laboratory conditions, the simulated artificial container habitat effects on larval development (days to pupation) did not differ significantly from an untreated control. The extended release spinosad formulation used warrants consideration as a rotational public health pesticide in artificial container habitats to augment integrated mosquito management programs in New Jersey.