The acaricidal efficacy of ceramic tiles treated at field application rates with either spinosad (Mozkill (c) 120 SC, 0.01 g ai/m(2)), deltamethrin (Impotek Deltamethrin (c) EW, 0.01 g ai/m(2)), permethrin + esbiothrin (Chrysamed (c), 0.1 g ai/m(2)), chlorpyrifos-methyl (Chlortoks (c) EC 50, 0.2 g ai/m(2)) or a mixture of alpha-cypermethrin/tetramethrin/piperonyl butoxide (Ecorex Alfa (c) SE, 0.01 g ai/m(2)), against larval Rhipicephalus turanicus and Argas persicus ticks was determined in laboratory bioassays. All ticks were initially exposed to treated tiles for 15 min then removed to non-treated containers and mortality evaluated for 15 min, 1 h, 6 h, and 24 h postexposure. Generally, A. persicus proved to be the most susceptible of the two species to all treatments. The alpha-cypermethrin/tetramethrin/piperonyl butoxide mixture was the quickest acting acaricide against larval A. persicus where 100% mortality was observed 15 min postexposure. For the rest of the treatments complete mortality was obtained at 1 h except for permethrin/esbiothrin which occurred at 6 h postexposure. Complete mortality of larval R turanicus occurred to deltamethrin and spinosad at I h postexposure with all acaricides providing 100% control at 6 h except permethrin/esbiothrin which only achieved 92% control through the end of the study (i.e. 24 h). Our results showed that spinosad would be a useful addition in a tick control program as an alternative for pyrethroids and organic phosphorus acaricides against both tick species. (C) 2009 Elsevier B.V. All rights reserved.