SOUTHERN FIRE ANT CONTROL IN NON-BEARING ALMOND, 2010

During 2010 we conducted a trial in Shafter, CA to evaluate the effects of two insecticides on the density of Southern fire ants in almonds. The trial was located in a 7.8 acre portion of a second-leaf orchard that contains alternating rows of the varieties Nonpareil and Monterey. Each plot was six rows wide and ten trees long on a 20 ft by 22 ft spacing. The plots were organized into a RCBD with 4 blocks of 2 treatments and an untreated check. The Lorsban treatment was applied to the floor of the orchard by ground rig at the rate of 4 pt in 40 gal water/acre on 6 Aug. Altrevin bait was applied using a hand spreader at the rate of 1.5 lbs/acre on 5 Aug. Southern fire ant densities were evaluated in each plot prior to treatment on 29 Jul and then weekly through 11 WAT. On each sample date, ant mounds were counted in a 44 ft × 180 ft area in the center of each plot. Additionally, on each sample date except 22 Oct, six plastic vials baited with 0.5 inch slices of hot dog were placed next to the irrigation hose in rows 2 and 5 at trees 3, 5, and 8 in each plot. After 1.5 h to 3 h, depending on environmental conditions during the trial, hot dog vials were picked up and placed in a freezer. The number of southern fire ants were then counted per vial for each plot. The average number of mound counts and ants per vial were analyzed by ANOVA using transformed data (square root (x + 0.5)) with means separated by LSD (P = 0.05).