ENHANCEMENT OF PERMETHRIN EFFICACY IN ACARICIDE-ATTRACTANT MIXTURES FOR CONTROL OF THE FOWL TICK ARGAS-PERSICUS (ACARI, ARGASIDAE)

Three acaricides, permethrin, propoxur and diazinon, were tested again st Argas persicus ticks in a test of susceptibility and in a multiple choice test in bioassay. A mixture of guanine hydrochloride and diatom aceous earth in saline was used as an attractant in bioassays, causing 53.1-95.7% assembly. The attractant was mixed with acaricides to redu ce their repellency and enhance their efficiency in bioassays. Permeth rin was the most toxic (LC95 at day 7=0.5-1.4 mg m(-2) depending on th e developmental stage) and most repellent acaricide. The mortality of males in the bioassay was significantly higher (76.7-94.3%, p < 0.01) when acaricide in amounts of 16 and 160 mu g of active ingredient per filter paper disc were mixed with attractant (0.5 mg per filter paper disc) instead of acaricide alone (20-45.7% mortality only). The mean p ermethrin residue on the lick body at the end of bioassay with the aca ricide-attractant mixture was significantly higher (13.62 +/- 11.64 ng ) than in experiments without the attractant (less than 1 ng). Propoxu r was less toxic (LC95 at day 7=0.9-1.9 mg m(-2)) and diazinon the lea st toxic (LC95 at day 7=2-9.4 mg m(-2)), both being not or only slight ly repellent. Males and females also assembled on filter paper discs t reated with propoxur without an attractant. Diazinon displayed signifi cant mortality only in amounts of 0.1 and 1 mg of active ingredient pe r filter paper disc with or without the attractant. Therefore, the rep ellency of permethrin can be reduced and its effectiveness enhanced wh en used in a mixture with an attractant. No similar effect was observe d with propoxur or diazinon.