HABITAT USE BY ADULTS OF ANASTREPHA-OBLIQUA (DIPTERA, TEPHRITIDAE) INA MIXED MANGO AND TROPICAL PLUM ORCHARD

We identified all essential Anastrepha obliqua (Macquart) resources (i .e., food, shelter, oviposition substrate [larval rearing medium], sit es to perform sexual activities, and pupation medium) within a diversi fied agroecosystem (plum trees planted adjacent to mango trees), and e xamined the relationship between the spatial arrangement and temporal characteristics (e.g., variable degree of foliage coverage in plum tre es) of habitat patches and resource use by local fly populations. Patt erns of resource use were correlated with habitat characteristics (e.g ., availability of shade, temperature, relative humidity, light intens ity) and varied significantly between sexes. Overall, females used plu m trees for feeding and oviposition, whereas males used them only for feeding. In contrast, females principally used mango trees for resting and feeding and males for sexual activities (courtship, copulation) a nd resting. We report significant differences in fly sightings accordi ng to sex, hour of day, and microhabitat. Of all fly sightings in the plum microhabitat (n = 396), 72.2% were females. In the mango microhab itat, 33.5% of 424 individuals sighted were female. Flies moved back a nd forth between microhabitats, especially during early morning and la te afternoon. We also provide data on sightings of the fly parasitoid Doryctobracon aerolatus (Szepligeti) in plum trees and adjacent native vegetation. The high degree of behavioral plasticity observed seems t o allow flies to respond efficiently to a heterogeneous and variable e nvironment. We discuss the theoretical and practical implications of o ur results with respect to insect behavioral responses to variable env ironments, insect movement, and control strategies based on habitat ma nipulation (use of trap crops).