Aqua Reslin and Biomist 30:30 technical permethrin and piperonyl butoxide were applied via ground ultra-low volume at a rate of 237 ml/min and 0.00196 kg active ingredient/ha against wild-caught adult Anopheles quadrimaculatus. The 2 formulations did not differ significantly at 31 m from the spray path (P < or = 0.05). However, at 61 and 91 m, percent mortality for 30:30 was significantly higher than for Aqua Reslin at each time after treatment (P < or = 0.05). Between 12 and 24 h, about 8% recovery was observed in mosquitoes treated with Aqua Reslin at 31 m.