Issue link: https://read.dmtmag.com/i/331109
14 JULY 2014 GOOD FRUIT GROWER www.goodfruit.com R esearch to find the best lure for trapping the spotted wing drosoph- ila serendipitously put Dr. Peter Landolt on the scent of a better way to deal with paper wasps. Landolt and colleague Dr. Dong Cha, who are based at the U.S. Department of Agri- culture's laboratory in Wapato, Washington, developed a new lure for spotted wing drosophila. Scientists in Mississippi, who are cooperating in the proj- ect, tested the new lure alongside a standard bait of wine and vinegar to trap spotted wing drosophila in blueber- ries. They found that the wine and vinegar mixture also attracted lots of paper wasps. This caught Landolt's attention because of a project he's been working on for the U.S. Air Force to find a way to control paper wasps in air traffic control towers. It also happens that another species of paper wasp, Polistes dominula, can be a troublesome pest in cherry orchards and vineyards in the Pacific Northwest. Landolt's experience with wasp attractants goes back to the late 1980s, when he worked for the USDA's Agri- cultural Research Service in Gainesville, Florida. He had a project funded by the National Aeronautical and Space Administration to rid the space shuttle launch pad of swarming wasps. Paper wasps tend to aggregate in the fall around elevated structures, such as treetops, towers, and high-rise buildings. At Cape Kennedy, female wasps had aggregated to overwinter inside a mechanical room at the top of a 490-foot-high launch tower. Male wasps swarmed around the outside of the room to intercept the females and mate with them, and in the process were alarming employees working on the tower. This hap- pened during a period when there had been a dearth of shuttle launches. Before Landolt and his colleagues were able to find a solution, NASA launched a shuttle. Since the whole launch pad goes up in flames as a shuttle lifts off, the problem was solved. %MVXVEJ½GGSRXVSP More recently, Landolt has been working on a similar project for the U.S. Air Force, which has a wasp problem at its air traffic control towers. Wasps are attracted to the towers, which in the southeastern United States tend to be the tallest structures on the horizon. Landolt said the design of the towers makes it easy for wasps to find their way inside the towers and into the control rooms. For the most part, the wasps that get inside the tower are the females that sting. "If you've got somebody at a panel watching radar of aircraft coming and going, coming and going, and they've got wasps crawling on them and walking across the screen, it can be unnerving," he said. Landolt said he and his colleagues have been work- ing to develop a chemical attractant for those wasps so they can be trapped. Traps for yellowjackets, which he previously developed, don't work well for paper wasps. A breakthrough came a couple of years ago when Landolt learned that those wine and vinegar traps being used in the spotted wing drosophila tests in Mississippi were attracting large numbers of Polistes metricus and P. bellicosus paper wasps, even though they'd not been noticed flying around. This was intriguing, given the dearth of useful baits and attractants known for paper wasps. It was the first indication of a useful bait for trapping paper wasps. Field tests at Moody Air Force Base in Georgia, Shaw Air Force Base in South Carolina, and the University of Florida, Gainesville, confirmed that wine and vinegar baits attracted paper wasps. However, in lab tests, when wasps were exposed to wine and vinegar separately, they preferred wine. They were attracted to ethanol (a major volatile of wine) and deterred by acetic acid (a major volatile of vinegar), which Landolt found somewhat surprising. Yellowjackets, The European paper wasp. Scientists work on paper-wasp lure Though often confused with yellowjackets, paper wasps do not respond to the same bait. by Geraldine Warner