Submitted to: Florida Entomologist
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/15/2003
Publication Date: 10/15/2003
Citation: Landolt, P.J., Reed, H.C., Ellis, D. 2003. Trapping yellowjackets (Hymenoptera: Vespidae) with heptyl butyrate emitted from controlled-release dispensers. Florida Entomologist. 86:323-328. Interpretive Summary: Because of continued concern with adverse environmental and human health effects of many pesticides in use, new methods and approaches are needed to control insect pests of tree fruits. Chemical attractants for insect pests are useful for trapping or killing targeted species, both for monitoring the presence of pests and for reducing their populations. Researchers at the USDA-ARS laboratory in Wapato, Washington are studying the attraction of several species of pest insects to chemical odors from fruits. Some species of yellowjackets are attracted to fruity esters structurally similar to heptyl butyrate. A dispensing system was developed for releasing heptyl butyrate and similar chemicals as a lure in traps. Additionally, it was demonstrated that heptyl butyrate is attractive to both the invasive German yellowjacket, as well as the southern yellowjacket. These results provide improvements in trapping systems for these and other wasps and an expansion of the application to additional pest species.
Technical Abstract: Numbers of workers of Vespula pensylvanica (Saussure) (western yellowjacket) and V. atropilosa (Sladen) trapped with heptyl butyrate in Washington increased with increased release of the attractant from vial dispensers, up to an estimated 2.3 milligrams heptyl butyrate per hour. Vespula germanica Fabricius (German yellowjacket) workers were also captured in significant numbers, and numbers of workers captured increased with increased release of heptyl butyrate up to an estimated 1.37 milligrams per hour. Numbers of workers of Vespula squamosa (Drury) trapped with heptyl butyrate in Oklahoma increased with increased release of heptyl butyrate from dispensers, up to an estimated 3.3 miligrams per hour. Vial dispensers, with holes of 6, 12, 22, and 33 mm diameter in the vial lid, lost 0.42, 1.37, 2.3, and 3.3 milligrams of heptyl butyrate per hour in the laboratory and these rates changed little over a period of 4 weeks, indicating close to a zero order rate of release pattern. Rates of loss of 2 ml heptyl butyrate applied to a cotton ball decreased with exposure time, from an initial rate of 6.0 milligrams per hour to near zero at 16 days post-treatment. Captures of wasps in traps sold commercially might be improved with the use of a controlled-release dispenser.