Submitted to: Journal of Insect Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/28/2011
Publication Date: N/A
Citation: Interpretive Summary: The little fire ant in a new invasive species to Hawaii and has the potential to be very disruptive in both agricutltural and urban settings. Called the fire ant due to its nasty sting, the ant has been reported in selected locations in Hawaii and these is a great need to monitor it for it’s spread throughout the island. We have identified a pheromone attractant that we believe can be used to help in the detection and perhaps control of this pest. Field trapping studies using this pheromone are reported in this paper. The results of this study point to the value having a chemical that will specifically trap little fire ant and being able to use this to determine the presence and spread of the insect in the environment.
Technical Abstract: Two detection methods for Wasmannia auropunctata (Roger), both employing the pheromone attractant 2,5-dimethyl-3-(2-methylbutyl)pyrazine (2-MeBu-diMePy), were compared with peanut butter, the most common current detection method for W. auropunctata in Hawaii. Comparisons of species specificity and detection reliability were conducted using a transect through a Macadamia nut orchard. The transect consisted of a series of three-tree-plots, each containing a one-way trap and a piece of double-sided tape, both treated with 2-MeBu-diMePy, along with a peanut butter coated stick. While there were no differences in the number of W. auropunctata detected with each method or differences in detection reliability (detecting the known presence W. auropunctata in a plot), the pheromone incorporating methods showed increased species specificity, almost exclusively retaining W. auropunctata. These results demonstrate the potential of pheromone detection methods to selectively capture target ant species even when other ants are present and abundant. Combined data from all three detection methods and a previous visual survey along the transect showed a marked difference in the frequency of cohabitation among ant species. Of the ten ant species collected, W. auropunctata was the lone ant species collected from a tree at a significantly higher frequency than all other ant species except P. fervens. Ninety four percent of the trees with W. auropunctata, had only W. auropunctata, confirming the previous observations that this species has a strong ability to displace other ant species. Wasmannia auropunctata microhabitat preferences were investigated using one-way traps containing 2-MeBu-diMePy, which were placed in three arboreal and three terrestrial locations. While the number of ants captured did not differ by trap placements, when grouped captures were significantly higher in arboreal than terrestrial microhabitats.