Evaluation of two trap deployment methods to manage the apple maggot fly (Dipt., Tephritidae)

Abstract: Two red sphere trap deployment methods were evaluated for their potential to capture apple maggot flies, Rhagoletis pomonella, and prevent oviposition. The first method was designed to simulate the interception of flies immigrating into an orchard by deploying odour‐baited traps on perimeter trees. The second method was designed to simulate the control of flies emerging from within an orchard by using odour‐baited traps on interior trees. Both methods were evaluated in an artificial orchard consisting of potted trees. In tests with hawthorn fruit (a favoured fly host) and released flies of high egg load, both the perimeter and within‐orchard trap deployment methods were successful at reducing oviposition compared with a control treatment without traps. Similar trends were observed with apples, a lower ranking fly host, although the results were not statistically significant. Spheres baited with butyl hexanoate (fruit odour) and ammonium carbonate (food odour) were more effective than unbaited spheres in terms of capturing released flies and preventing oviposition. Based on the results of this study, both perimeter and within‐orchard trapping appear to have potential to reduce fruit injury and manage R. pomonella in commercial orchards.