Data from: A self-reinforcing mechanism extends one-way trap performance in <i>Wasmannia auropunctata</i> (Hymenoptera: Formicidae)

Little fire ant, Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae), is an invasive ant with negative impacts on biodiversity and agriculture throughout the tropics and subtropics. These ants can be captured in one-way traps using the alarm pheromone attractant 2,5-dimethyl-3-(2-methylbutyl)pyrazine, but many trap parameters remain unknown. This field study was conducted to determine one-way trap performance parameters, including trap longevity, maximum trap capacity, and trap capture mechanism. Experiment 1 assessed the longevity of W. auropunctata captures in one-way traps over two 57-day periods. Pheromone-treated traps captured 79 ± 9 ants/day with a maximum one-day capture of 4,938 ants, while control traps without pheromone captured 1.3 ± 0.2 ants/day, with a maximum one-day capture of 112 ants. A bent-cable model was used to estimate that pheromone-treated traps remained attractive for 42.3 days (95% confidence interval 38.9–48.7 days), even at what are likely very low concentrations of alarm pheromone. Experiment 2 assessed the maximum number of ants that could be captured in a single trap by leaving traps containing pheromone in macadamia trees for 57 days, concurrent with Experiment 1. Traps serviced in this way, not daily but only at the end of the trial period, captured 70 ants/trap. Experiment 3 was designed to explore the unexpected trap longevity observed in Experiment 1 by testing three trapping mechanism hypotheses: 1) ants establish trails or other markers to traps, 2) captured ants attract other ants to traps, and 3) ants are slow to find traps (discovery lag). Experimental results support hypotheses 1 and 2.