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 fro m hawthorn or apple trees and were released into patches of host trees containing hawthorn or apple fruit in an open field. There were no de tectable differences between hawthorn-origin females in patches of haw thorns and apple-origin females in patches of apples in numbers of fem ales 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 f emales in patches of hawthorns behaved similarly to hawthorn-origin fe males 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 ofte n and laid only 20% as many eggs before departing a patch. Our finding s support the hypothesis of G. L. Bush that R. pomonella flies of hawt horn and apple origin represent distinct host races.