Ecotone effect on the fruit fly assemblages (Diptera: Tephritidae) in natural and anthropized environments.

Abstract

Various species of fruit flies are important pests of fruit cultures and in some crop of vegetables worldwide. Studies of their population patterns, ecological processes and mechanisms that influence their sampling and distribution in the ecosystems, provides important information to support researches on species diversity and ecologically based pest control programs. The aims of this paper were to analyze the patterns of fruit fly species: diversity, abundance and composition in the margin and inside of a fragment of native forest (35 ha); on the margin and in the inside a commercial orchard (2.5 ha). This research was carried out in transects in a fragment of semideciduous forest and in a commercial orchard in the region of Dourados, Mato Grosso do Sul, Brazil. A total of 1,918 adult fruit flies: 1,350 Ceratitis capitata (Wiedemann) (♂♂+♀♀) and 568 of the genus Anastrepha Schiner (275♂♂ + 293♀♀) from six infrageneric groups and 12 different species were captured. C. capitata (80%), and Anastrepha sororcula Zucchi were the most abundant species, being this last one representing 50.68% of individuals in the genus Anastrepha. There are significant differences in species diversity of fruit flies caught in the traps installed in the edge and inside of both environments: traps installed in the forest edge had higher diversity index (H' = 2.13) in compare to the inside of forest (H' = 1.67), with the same pattern repeated in the orchard: edge (H' = 0.55) and inside (H' = 0.41). The results in this paper corroborate with the prediction that in ecotonal areas between environments there are higher diversity in compare with the inside of each of the confronting ecosystems. The technique proposed here saves time, effort and resources in rapid inventories for sampling fruit fly species richness in natural forests and large fruit tree orchards.