LIQUID BAIT FORMULATIONS for CONTROLLING the ODOROUS HOUSE ANT (HYMENOPTERA: FORMICIDAE)

Abstract:
The odorous house ant, Tapinoma sessile (Say), is a severe pest of structures. We have investigated whether the use of liquid bait formulations is an effective strategy for control of this peripatetic, tramp-ant species. Sixteen homes or business establishments, located in or near Cape May, NJ, were selected for the study. Fifteen of the structures were assigned to one of three treatments, five structures per treatment, and the remaining structure served as a control and was left untreated. Each property was initially scouted for ant trails, and we recorded the number of ants crossing a selected point along a trail in five minutes; a bait station was positioned nearby the trail. No structure received fewer than three stations, and none greater than seven. At the control site, trails were similarly located and counted, but no bait stations were put in place. At 1, 2, 4, 6, and 8 weeks ant numbers were counted along extant trails, and bait solutions were added to stations as needed. Results showed that two formulations containing 50 ppm imidacloprid (Pre-Empt® Liquid Ant Bait) reduced ant numbers by over 80% after 6 weeks, as did a formulation containing boric acid (Drax Liquidator®). Reductions were directly attributable to the baits, as ant numbers remained relatively stable at the control site throughout the study. Liquid formulations show considerable efficacy in the control of odorous house ants.