Padrões populacionais de moscas frugívoras (Diptera: Tephritoidea) em um fragmento de floresta semidecidua e em um pomar comercial da região de Dourados-MS, Brasil

Abstract

Populational patterns of frugivorous flies (Diptera: Tephritoidea) in a fragment of Semidecidual Forest and in an orchard in the Region of Dourados, MS, Brazil. The Fruit flies are important pests in the word wide horticulture. These pests cause significant losses in the production of fruits and are responsible for the limitation in the free traffic of fruits, because their presence induce quarantine restrictions by importer countries of fruit and vegetables. The extension of loses are directelly related to the abundance of frugivorous fly populations. By other hand, the populations of Tephritoids are influenced by the abiotic (temperature, relative air humidity and rainfall) and biotic factors (host fruit availably and natural enemies action). This survey was carried out in a fragment semidecidual forest (22º12’ S e 54º55’W) and in a commercial mixed orchard (22º 13’ S 54º 43’ W). The aim of this paper is: 1) to compare the abundance and the species richness of fruit flies caught in McPhail traps instaled in the edge and in the middle of the native forest, in the edge and middle of the commercial orchard; 2) survey the population fluctuation of the most abundant species of fruit fly in both ecosystems, looking for some relationship with the abiotic factors and with plant phenology. C. capitata was the most abundant species, representing more than 80% of the caught adults of fruit flies. From Anastrepha spp. were identified 292 females, belonging to 12 species, being A. sororcula the most abundant fly (50,68%). C. capitata and A. sororcula were dominant. There were no significant differences in the abundance of frugivorous flies caught in the edge or in the middle of the forest neither in the edge and middle of the commercial orchard. Although, there are significant difference in the species diversity. The traps installed in the edge of the forest shows higher diversity index (H’ = 2.12). By other hand, the traps installed in the middle of commercial orchard captured higher species richness but with lower diversity index ((H’ = 0.408). The climatic factors were not the only ones that interfered in the population fluctuation of Anastrepha spp. and C. capitata in the surveyed environments. There was no correlation among the population fluctuation of the Anastrepha species with and the phenological stages of the fruit trees. But C. capitata populations were positively correlated with the stages of flowering, green fruits, ripe fruits and vegetative stages. The results in this paper corroborate with the prediction that in the ecotone there are higher species richness and diversity that in the middle of each one of the confronting ecosystems.