CONTROL OF RED IMPORTED FIRE ANT ON CITRUS BEDS IN SOUTHWEST FLORIDA WITH TOXIC BAITS.

The trial was conducted at the Southwest Florida Research and Education Center in Immokalee on 24 unplanted citrus beds, 28 ft wide separated by 16 ft swales with 3ft between bed tops and swale bottoms according to standard local practices. Beds were newly made and that most, if not all RIFA colonies were of recent origin, including new mounds appearing toward the end of the trial. Treatment plots consisted of 3 adjacent sections of bed 200 ft length with only the middle bed section used for sampling. Experimental design was replicated complete block with 4 replications and 4 treatments applied at 1 lb/acre: Ascend (0.011% abamectin), Logic (1% fenoxycarb), Amdro (0.73% hydromethylnon), AC303-630 (0.005%), a 5th treatment, Bushwacker (18% boric acid) applied at 3 lb/ac, and an untreated control. Ant baits were spread over a 30 ft swath from the center of the beds with a Herd GT-77A seeder spreader mounted on a Ford tractor on 3 July 1996 at 5:00-8:30 p.m. Pre-counts taken on 2 Jul consisted of a complete census of active mounds and a count of ant captured with a peanut butter bait. Mounds were counted and baits were placed within the central 100 ft of the central bed along an 8 ft herbicided band centered 3 ft from on the edge of the bed. Mounds were considered active if ants could be observed following a gentle disturbance. Large (500mm) petri plates were used as bait stations, filled with 10 g of peanut butter and placed out into the sampling area in the evening to be collected the next morning and placed into the freezer for a minimum two hours. Fire ants caught in the petri dishes were then counted and for the last 4 post-treatment counts ants were also weighed as was the remaining peanut butter so that consumption could be estimated. A total of 5 post-treatment samples were taken on 24 Jul, 14 Aug, 4 Sep, 16 Oct and 13 Nov.