Location: Fruit and Vegetable Insect Research
2013 Annual Report
Wasps at air traffic control towers were sampled to determine the species makeup and to determine where males and females were at when swarming about the towers. We found that Polistes metricus and Polistes bellicosus were the dominant species at towers in South Carolina and Georgia. Most wasps inside towers were female, while wasps outside of the towers were primarily males. Because the problems with the wasps are well defined in time and space, they may be managed by trapping or baiting if a suitable attractant is available.
A set of known wasp attractants were evaluated at several sites in the southeast U.S. to determine their attractiveness to P. metricus and P. bellicosus. At best, there was a weak response to acetic acid with isobutanol, a chemical blend that is attractive to Polistes aurifer and Polistes fuscatus. It was concluded that there is a need for a novel chemical attractant for these species of wasps.
Subsequently, large numbers of paper wasps of interest were captured in traps baited with a combination of a wine and a vinegar. Subsequent work aimed to determine which chemicals in these materials are responsible for that attraction, so that a synthetic lure may be produced that mimics the original material. A laboratory olfactometer assay was used to determine responses of male and female Polistes bellicosus and Polistes metricus to wine, vinegar, ethanol, and acetic acid. A combination gas chromatograph and electroantennal detector (EAD) was used to determine which volatile compounds from a wine a vinegar can be detected by the antennae of the wasps. Two field experiments were conducted to evaluate wasp attraction (captured in traps) to wine, vinegar, and sets of volatile chemicals from these materials. It was determined that the original response of wasps to wine and vinegar is due principally to chemicals in the wine (not the vinegar), including ethanol. Wasps were trapped with a set of EAD-active wine chemicals, but more were trapped with wine indicating that more work needs to be done to optimize the lure. This problem could be due to chemicals that are detected by the antenna but are deterrent, and to an inadequate formulation for ethanol in traps. Subsequent testing is planned to evaluate the roles of possible deterrents in chemical blends tested, and to provide a more stable controlled release system for testing of the wine chemicals in the field.