Issue link: http://read.dmtmag.com/i/331109
www.goodfruit.com GOOD FRUIT GROWER JULY 2014 15 A western yellowjacket (Vespula pensylvanica) queen on a young nest. Yellowjackets may be mistaken for paper wasps. which are related to paper wasps, are attracted to acetic acid combined with isobutanol. The wasps' orientation to fermented baits is likely to be food-finding behav- ior that they use in nature to locate fer- mented sweet materials. In the field, paper wasps feed on carbohydrate-rich foods such as fruit, sap, honeydew of sucking insects, and plant nectaries. As a sweet fruit product ages, it ferments first to alcohol and then to vinegar. Landolt said it could be that the paper wasp's preference for alcohol matches up with its preference for natural food sources that have not aged too much. Based on these results, Landolt and Cha worked in the lab to isolate and identify volatile chemicals in wine that are particularly attractive to the wasps and could be used as a lure. This spring, they sent out an experimental lure containing a combination of volatiles that they identified to test on paper wasps in Florida, Georgia, Mississippi, Texas, and South Carolina. Meanwhile, the researchers have done lab tests with P. dominula, the spe- cies that attacks cherries and grapes in the Pacific Northwest, to find out how it reacts to wine and vinegar. Landolt said P. dominula, known as the European paper wasp, is gener- ally only a problem in small orchards or vineyards with nearby buildings that provide enclosed nesting places for the wasps. The insects commonly nest under eaves or within enclosed spaces such as in meter boxes, inside pipes, or between shakes. "They generally don't nest out in the field or orchard," he said. Paper wasps are not usually a big prob- lem in cherries, other than in late dis- tricts, because the fruit is picked before populations explode in the late summer. Landolt said P. dominula is often confused with yellowjackets, but the wasps need to be accurately identi- fied because of paper wasps not being attracted to yellowjacket traps. • 1615 W. Ahtanum • Yakima, WA 98903 • 509-248-8785, ext. 612 For the representative nearest you, visit our Web site: www.orchard-rite.com Get the Orchard-Rite® story from your nearest representative: I have been farming since 1974, and currently grow 70 acres of cherries. Last year, we put in two Orchard-Rite® Wind Machines, giving me frost protection on about 40-45 acres. We had a very cold, wet spring. These wind machines were very beneficial. Because of our Orchard-Rite® Wind Machines, we actually had our best crop in what would normally be the poorest-producing portion of the orchard. We are installing two more wind machines this year. The Orchard-Rite crew is great to work with. Anytime I've called for information or assistance, they have been Johnny-on-the-spot. Don Nusom Gervais, Oregon "The Orchard-Rite crew is great to work with." "The Orchard-Rite crew is great to work with." Orchard-Rite® Wind Machines • www.orchard-rite.com PHOT O B Y R O G ER AKRE PHOTO BY DUANE HOLDER The European paper wasp Polistes dominula is a late-season pest of cherries. "If you've got somebody watching radar of aircraft coming and going, and they've got wasps crawling on them, it can be unnerving." —Dr. Peter Landolt PHOT O C O U R T E S Y OF R O GER AKRE