Distribution and Activities of Anastrepha fraterculus (Diptera: Tephritidae) Flies on Host and Nonhost Trees

Quantitative results of observations in nature in Brazil of the diel pattern and location of activities of South American fruit flies, Anastrepha fraterculus (Wiedemann), on host trees with and without fruit, and on nonhost trees without fruit, revealed the following. At dawn (ca. 0600 h), both sexes were at rest on the bottom surface of leaves near the tops of nonhost and host trees. Sexual activity (male calling) began at ca. 0700 h and ceased before 1100 h. It occurred on nonhosts as well as hosts, with all observed copulation initiations and mating pairs occurring only near the top of a tall nonhost tree. Feeding and oviposition began at ca. 0800 h, peaked from midmorning to midafternoon, and ended before 1800 h. Feeding occurred almost exclusively on ripe host fruits exuding juice, whereas oviposition occurred almost exclusively on unripe host fruits. All flies observed at 1800 h (dusk) and afterward were either at rest on the bottom surface of leaves near the tops of trees or were in flight toward tree tops. Our findings on A. fraterculus are discussed in relation to the diel pattern and location of activities of other Tephritidae studied in nature.