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 mat ing behavior of wild Anastrepha striata Schiner flies. Observations we re made in a greenhouse (5 m wide, 6 m long, 4 m tall) in which a tota l of 91 potted guava, sapodilla, orange, and mango trees had been plac ed. Overall, we found statistically significant differences in fly act ivity patterns depending upon the hour of day and sex of fly. Most fli es (62.3%) emerged between 0900 and 1200 hours with no significant dif ferences between sexes. Young flies (I-15 d of age) fed preferably on napkin strips soaked in a yeast hydrolysate-sucrose mixture, whereas o lder flies (>30 d of age) preferred ripe fruit. Bubbling and regurgita tion behaviors were common and were correlated with feeding times. Ind ividual flies regurgitated a mean of 23.5 +/- 1.5 SE drops and reinges ted them within 12 +/- 3.9 min. Oviposition activity by females (which included ovipositor dragging on the fruit surface) followed a bell-sh aped 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 s hort- 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 strikin g feature of the mating behavior (not previously reported in other Ana strepha species) is the formation of female-male pairs that interact f or prolonged periods (mean of 21.3 +/- 2.3 min, n = 245). While intera cting, flies exhibit elaborate courtship behaviors such as repeated la bellum-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 ma ting attempts per pair, with a mean duration of 7.3 +/- 0.3 s per atte mpt. Most mating attempts were unsuccessful (unsuccessful/successful m ating 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).