REDUCTION OF IMMATURE IXODES-SCAPULARIS (ACARI, IXODIDAE) IN WOODLOTSBY APPLICATION OF DESICCANT AND INSECTICIDAL SOAP FORMULATIONS

The efficacy of two commerically available formulations of a desiccant and insecticidal soap were compared with chlorpyrifos wettable powder (0.6 kg [AI]/ha) against the immatures of Ixodes scapularis Say in a woodlot in Westchester County, New York. The desiccant formulation (Dr ione) was applied at 61.04 kg/ha and an insecticidal soap (Safer's) wa s applied as a mixture (39 ml concentrate per liter of water) at 107 l iters/ha. By 1 wk after application, all treatments significantly redu ced the density of nymphs in comparison to untreated plots. Only plots treated with chlorpyrifos had significantly reduced nymphal densities 2 wk after application. By 6 wk after application, there were no diff erences in nymphal density between treated and untreated plots, which was likely the result of a decline in overall nymphal populations. Non e of the treatments against nymphs affected larval densities sampled 6 wk after application. Larval density was significantly lower 1 wk aft er application in plots treated with chlorpyrifos and Safer's insectic idal soap than in untreated plots. By 2 wk after treatment, only plots treated with chlorpyrifos had lower larval densities than untreated p lots. Results indicate that the desiccant Drione and Safer's insectici dal soap are good for short-term control of immature I. scapularis.