Field Trapping the Little Fire Ant,Wasmannia auropunctata

Abstract

Two detection methods for the little fire ant, Wasmannia auropunctata (Roger) (Hymenoptera: Formicidae), both employing the pheromone attractant 2,5-dimethyl-3-(2-methylbutyl)pyrazine (2-MeBu-diMePy), were compared with peanut butter based detection, in order to evaluate differences in species specificity and detection reliability. Trapping was conducted using a transect through a macadamia orchard on the island of Hawaii. The transect consisted of a series of three-tree plots, each plot contained a peanut butter coated stick (the most common detection method used for W. auropunctata in Hawaii), a one—way trap treated with 2-MeBu-diMePy, and a piece of double-sided tape treated with 2-MeBu-diMePy. While there were no differences in the number of W. auropunctata counted with each detection method, and no differences in detection reliability (detecting the known presence of W. auropunctata in a plot), the pheromone—incorporating methods showed greater species specificity, retaining W. auropunctata almost exclusively. 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 10 ant species collected, W. auropunctata was found as the sole ant species on a given tree at a significantly higher frequency than all other ant species except Pheidole fervens. 94% percent of the trees with W. auropunctata had only W. auropunctata, supporting previous observations that this species tends to displace other ant species. In addition, W. auropunctata microhabitat preferences were investigated using one—way traps containing 2-MeBu-diMePy, which were placed in three arboreal and three non—arboreal locations. While the number of ants captured did not differ by trap placement, when grouped, captures were significantly higher in arboreal than non-arboreal microhabitats.

Identification of hydroxymethylpyrazines using mass spectrometry

“…We believe that hydroxymethylpyrazines are more abundant in natural systems than is currently known and suggest that the lack of knowledge about their fragmentation patterns results in them passing unidentified in many systems. With the prevalence of pyrazines as flavouring agents in foods, as bacterial volatiles and with their growing recognition as insect semiochemicals, the results from our investigation of the EIMS fragmentations of hydroxymethyl‐substituted pyrazines presented here, together with previous reported GC behaviour, should aid other scientists in efforts to identify this important class of natural products using GC–MS techniques.…”

Novel reusable canopy trap for sampling arboreal populations of electric ant, Wasmannia auropunctata (Hymenoptera: Formicidae)

“…Derstine et al . (2012) similarly found that Tanglefoot™ is a poor choice for W. auropunctata detection.…”

Electrophysiological and Alarm Responses of Solenopsis invicta Buren (Hymenoptera: Formicidae) to 2-Ethyl-3,5-dimethylpyrazine

“…Previous field studies have demonstrated that traps baited with pheromonal pyrazines can increase species-specific detection of the little fire ant, Wasmannia auropunctata [32]. Both laboratory and field studies indicated that the addition of (Z)-9-hexadecenal, a trail pheromone component of Argentine ant, Linepithema humile (Mayr), could enhance food consumption [33,34].…”