Comparison of electrostatic versus nonelectrostatic ULV sprays of Aqua Reslin (TM) against Anopheles quadrimaculatus adults

An electrostatic truck-mounted spray system (Spectrum, Houston, TX) and a n onelectrostatic spray system (Micro-Gen G-4, San Antonio, TX) were tested t o determine the feasibility of electrostatically charging Aqua Reslin(TM), a water-based permethrin insecticide, and ascertain whether an electrostati c charge would increase the efficiency of Aqua Reslin against Anopheles qua drimaculatus adults. parameters tested for both machines included mean mass median diameter (MMD) of droplets, number of drops per cm(2), and posttrea tment percent mortality at 1, 12, and 24 h. Results indicated that the elec trostatically charged droplets produced greater mortality at each distance and hour posttreatment. Correlation coefficients and linear equations were calculated for distance-mortality, MMD-mortality, drops per cm(2)-mortality , distance-drops per cm(2), distance-MMD, and MMD-drops per cm(2). Results indicated that the electrostatic drops demonstrated strong correlations bet ween each paired variable, whereas the nonelectrostatic drops showed poor c orrelation between drops per cm(2)-mortality, distance-drops per cm(2), and MMD-drops per cm(2). However, from this trial, these differences cannot be attributed purely to the electrostatic charge because significant differen ces in droplet size can affect spray performance.