BEHAVIORAL-DIFFERENCES BETWEEN HAWTHORN-ORIGIN AND APPLE-ORIGIN RHAGOLETIS-POMONELLA FLIES IN PATCHES OF HOST TREES

We compared patterns of patch residence and oviposition of Rhagoletis pomonella (Diptera: Tephritidae) females that originated as larvae from hawthorn or apple trees and were released into patches of host trees containing hawthorn or apple fruit in an open field. There were no detectable differences between hawthorn-origin females in patches of hawthorns and apple-origin females in patches of apples in numbers of females observed on food, fruit or foliage or in numbers of eggs laid in fruit during the course of the 7-h experimental period. Apple-origin females in patches of hawthorns behaved similarly to hawthorn-origin females in patches of hawthorns. In contrast, hawthorn-origin females in patches of apples differed significantly from apple-origin females in patches of apples. The former were observed on fruit only 40% as often and laid only 20% as many eggs before departing a patch. Our findings support the hypothesis of G. L. Bush that R. pomonella flies of hawthorn and apple origin represent distinct host races.