Ability of Three General-Use Pesticides To Suppress Nymphal Ixodes scapularis and Amblyomma americanum (Acari: Ixodidae).

We evaluated 3 over-the-counter pesticides for their ability to suppress host-seeking Ixodes scapularis and Amblyomma americanum nymphs. We applied liquid concentrate and granular formulations of Bayer Advanced Complete Insect Killer, Spectracide Triazicide Insect Killer, and Ortho Bug-B-Gon to forest plots using equipment available for purchase at retail home improvement outlets. All 3 liquid formulations provided rapid knockdown (>= 98% control) of both species 1 day after application. Liquid Ortho Bug-B-Gone provided 100% suppression of I. scapularis throughout the 28-day postapplication period, while the other 2 liquid materials provided > 95% control after 28 days. All liquid products also provided >= 95% control of A. americanum nymphs after 28 days. Granular formulations provided less consistent results, including lower 1-day knockdown rates for both species, due to very dry conditions, which prevented adequate release of the active ingredient from the carrier materials. After it rained in the study area, 7 and 14 days after application, we observed >= 99% suppression of both species. At 28 days posttreatment, control ranged between 87.5% and 95.6% for I. scapularis and between 89.3% and 94.4% for A. americanum. We show that these over-the-counter acaricides effectively suppressed 2 medically important tick vectors for at least 4 wk, and they provide a cost-effective tick control option for homeowners. In general, liquid formulations provided more rapid and greater and more consistent suppression than granular formulations, which may have implications for homeowner use of these products.