Grape Juice as an Attractant for Anastrepha suspensa (Diptera: Tephritidae) and Zaprionus indianus (Diptera: Drosophilidae)

Authors: Epsky, Nancy; Gill, Micah; Mangan, Robert

Submitted to: Journal of Economic Entomology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 7/6/2014
Publication Date: 2/28/2015
Citation: Epsky, N.D., Gill, M.A., Mangan, R.L. 2015. Grape Juice as an Attractant for Anastrepha suspensa (Diptera: Tephritidae) and Zaprionus indianus (Diptera: Drosophilidae). Journal of Economic Entomology. 139(1-2):114-122.

Interpretive Summary: Improved attractants are needed for use in traps for fruit fly pests including the caribfly, a pest of guava and citrus in Florida, and African fig fly, which is a pest fruit fly that has spread rapidly through much of the eastern United States since it was first found in Florida in 2005. Aqueous grape juice baits have been found to be effective for other fruit fly pests in Mexico and Brazil, and may provide an economical bait and improved attractant for the caribfly and African fig fly. Therefore, scientists at SHRS conducted research in south Florida to test aqueous grape juice as a bait for the caribfly and African fig fly. They found that few caribflies were captured in grape juice bait in comparison with capture in standard baits and lures for this pest. However, actively fermenting grape juice bait was highly attractive to African fig flies. Fermenting grape juice bait may provide an improved attractant that can be used to detect this fly in areas currently fly free or to monitor African fig fly populations in areas already infested. This information will be used by state and federal regulatory agencies, extension personnel, as well as fruit growers.

Technical Abstract: In field tests conducted in south Florida to test grape juice as an alternative inexpensive bait for Anastrepha suspensa Loew, high numbers of Zaprionus indianus Gupta were captured in traps baited with aqueous grape juice. These experiments included comparisons of grape juice with standard A. suspensa baits (ammonium acetate + putrescine lures, or torula yeast) or wine, a bait found previously to be attractive to Z. indianus. Effect of different preservatives (polypropylene glycol, polyethylene glycol, proxel, or sodium tetraborate) and bait age were also considered. More A. suspensa were captured with the standard baits than any aqueous grape juice formulation, although grape juice with preservative tended to capture more A. suspensa than grape juice without preservative. In contrast, grape juice was highly effective for capturing Z. indianus. Grape juice solutions without preservative that were freshly prepared (0 d) or aged in the laboratory for 3-4 d were the most attractive to Z. indianus. Factors that affected fermentation rate e.g., type of preservative, grape juice concentration, time period bait solution was aged, whether bait was aged in the laboratory or in the field, affected number of flies captured. Although these studies were initiated with the aim of finding either an improved attractant or inexpensive bait for A. suspensa, we found instead that actively fermenting aqueous grape juice may be a highly effective bait for Z. indianus.