Efficacy of Biomist 30:30 and Aqua Reslin against Anopheles quadrimaculatus in Arkansas.

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.

Field trial efficacy of two formulations of Permanone against Culex quinquefasciatus and Anopheles quadrimaculatus.

Tests were conducted during the summer of 1996 to evaluate the effectiveness of different formulations of permethrin, Permanone 31-66 and Aquareslin, against Anopheles quadrimaculatus and Culex quinquefasciatus. Tests of both formulations were conducted at rates of 2.019 and 3.926 g AI/h with each formulation/rate replicated 3 times. Results indicate significantly greater control of both pest species at the higher application rate for both formulations. The high rate of Permanone 31-66 proved more effective than that of Aquareslin. Exposure at the low rate for both formulations provided inadequate adult control that was particularly pronounced against Cx. quinquefasciatus. Regardless, negligible recovery of exposed adults was observed at any formulations/rate. No significant differences in mortality were noted for any formulation/rate relative to distance downwind. However, volume median diameter and droplets/cm2 were significantly affected by distance downwind. Furthermore, volume median diameter and droplets/cm2 were both determined to significantly affect mortality in both mosquito species (P < or = 0.05). Overall, results indicate that Permanone 31-66 and Aquareslin applied at a rate of 3.926 g AI/h were effective.

Assessment of Anopheles quadrimaculatus response to permethrin and resmethrin by topical application.

Topical applications with field-captured mosquitoes provided LD50 estimates ranging from 13.3 to 20.0 ppm for permethrin and 8.5 to 18.9 ppm for resmethrin in the Stuttgart, AR, area in 1993. Mosquitoes collected from the abatement area appeared to be more susceptible to resmethrin than those from outside the area (8.5 ppm vs. 18.9 ppm). The observed difference was not great enough to be of concern from an economic or control standpoint. The data provided a firm baseline for future assessment of changes in susceptibility to these 2 materials. Mosquitoes collected in Walnut Ridge, AR, were susceptible to permethrin and resmethrin within the same range as the Stuttgart populations, but the limited number of observations preclude firm LD50 estimates.