SEASONAL POPULATION FLUCTUATIONS AND ECOLOGICAL IMPLICATIONS FOR MANAGEMENT OF ANASTREPHA FRUIT-FLIES (DIPTERA, TEPHRITIDAE) IN COMMERCIAL MANGO ORCHARDS IN SOUTHERN MEXICO

We report the results of a large scale (5 orchards) and long-term (5 y r) study on seasonal population fluctuations of Anastrepha fruit flies in commercial mango orchards in the Soconusco Region, Chiapas, Mexico . Out of 10 Anastrepha species present in these or chards, West Indian fruit fly A. obliqua (Macquart), and Mexican fruit fly, A. ludens (Lo ew), accounted for 96.6% of all individuals captured in McPhail traps. A. obliqua was by far the dominant species, accounting for 66.1% of a ll individuals captured. Anastrepha populations fluctuated markedly fr om year to year during our study. Furthermore, even though we worked i n orchards that were relatively close to each other, we discovered sig nificant differences in terms of total numbers of flies captured per o rchard and Anastrepha species diversity in each orchard. Most flies (6 2.3%) were captured in traps placed in the periphery of orchards (i.e. , edge traps). Also, most (approximate to 90%) of the mangoes sampled in commercial orchards were infested by A. obliqua, despite the fact t hat significant numbers of A. ludens adults were present in every orch ard. In contrast, mangoes sampled at higher elevations were predominan tly infested by A. ludens. We compare our results with similar studies in other parts of Mexico and Latin America and discuss our findings i n light of their practical implications.