BASIC PATTERNS OF BEHAVIOR IN WILD ANASTREPHA-STRIATA (DIPTERA, TEPHRITIDAE) FLIES UNDER FIELD-CAGE CONDITIONS

We describe the diel patterns of feeding resting, oviposition, and mating behavior of wild Anastrepha striata Schiner flies. Observations were made in a greenhouse (5 m wide, 6 m long, 4 m tall) in which a total of 91 potted guava, sapodilla, orange, and mango trees had been placed. Overall, we found statistically significant differences in fly activity patterns depending upon the hour of day and sex of fly. Most flies (62.3%) emerged between 0900 and 1200 hours with no significant differences between sexes. Young flies (I-15 d of age) fed preferably on napkin strips soaked in a yeast hydrolysate-sucrose mixture, whereas older flies (>30 d of age) preferred ripe fruit. Bubbling and regurgitation behaviors were common and were correlated with feeding times. Individual flies regurgitated a mean of 23.5 +/- 1.5 SE drops and reingested them within 12 +/- 3.9 min. Oviposition activity by females (which included ovipositor dragging on the fruit surface) followed a bell-shaped pattern with a peak at 1200-1300 hours. Mean clutch size was 1.5 +/- 0.13. A. striata mating behavior is very complex and encompasses short- and long-range interactions between males and females. A larger proportion of males called singly (91.3%), but lek formation was also observed (8.7% of all calling males did so in a lek). The most striking feature of the mating behavior (not previously reported in other Anastrepha species) is the formation of female-male pairs that interact for prolonged periods (mean of 21.3 +/- 2.3 min, n = 245). While interacting, flies exhibit elaborate courtship behaviors such as repeated labellum-to-labellum contacts (during which actual male-female substance transfer takes place) and circular displacements in front of the mate. In 78 pairs studied in detail, we observed a mean of 13.3 +/- 1.9 mating attempts per pair, with a mean duration of 7.3 +/- 0.3 s per attempt. Most mating attempts were unsuccessful (unsuccessful/successful mating attempt ratio, 10:1). Actual copulations had a duration of 29.2 +/- 2.3 min (n = 45). A. striata behavior is discussed in relation to behavior of other Diptera (including Anastrepha).