ABSTRACT
Studies of community assembly have emphasized snapshot comparisons of spatially replicated samples from "natural" assemblages. Agro-ecosystems are characterized by relatively little habitat heterogeneity and no dispersal barriers for actively flying insects. Therefore, dynamic patterns of species segregation and aggregation are more likely to reflect the direct or indirect effects of species interactions. We studied the temporal organization of a guild of 21 congeneric species of Anastrepha that colonized fruit orchards in Monte Alegre do Sul, São Paulo, Brazil. This assemblage also included the introduced Mediterranean fruit fly Ceratitis capitata. One hundred six consecutive weekly censuses (11 Jan 2002-16 Jan 2004) of flies in guava, loquat, and peach orchards revealed a pattern of minimum abundance during the coldest months of each year (June and July) and a maximum abundance during periods of flowering and fruit ripening. Overall, phenological overlap was greater than expected by chance. However, conditioned on the pattern of seasonal abundances, temporal occurrence and abundance matrices exhibited patterns of significant species segregation and anti-nestedness. In each year, the 3 orchards contained a small number of species pairs that exhibited statistically significant temporal segregation or aggregation. Most aggregated and segregated pairs reflected seasonal shifts in species presences that were not related to variation in air temperature. Most of the significant pairwise associations involved C. capitata: 8 of the 11 segregated pairs and 2 of the 7 aggregated pairs. These results suggest that species interactions between introduced and native species can be an important determinant of species associations in agro-ecosystems.
Subject(s)
Ceratitis capitata/physiology , Ecosystem , Tephritidae/physiology , Tropical Climate , Air , Animals , Biodiversity , Brazil , Female , Models, Theoretical , Species Specificity , Temperature , Time FactorsABSTRACT
The objective of this work was to register the infestation of C. capitata on papaya fruits in Minas Gerais State. Papaya fruits were collected, in a commercial orchard, in Jaíba, north of the State of Minas Gerais. C. capitata was the only specie collected (794 individuals). Doryctobracon areolatus (Szépligeti) was collected parasitizing C. capitata larvae/pupae. The level of infestation was of 7,7 pupae/kg of fruit or 1,4 pupae/fruit, in average. C. capitata is registered for the first time on papaya fruits in the State of Minas Gerais.
Subject(s)
Carica/parasitology , Ceratitis capitata , Animals , BrazilABSTRACT
Este trabalho teve como objetivo registrar a infestação de C. capitata em frutos de mamoeiro em Minas Gerais. Foram coletados frutos em uma área comercial de mamão, em Jaíba, norte do estado. C. capitata foi a única espécie obtida (794 indivíduos). Doryctobracon areolatus (Szépligeti) foi encontrado parasitando larva/pupa de C. capitata. O índice de infestação encontrado foi em média de 7,7 pupários/kg de fruto ou 1,4 pupários/fruto. C. capitata é registrada pela primeira vez em frutos de mamão em Minas Gerais.
The objective of this work was to register the infestation of C. capitata on papaya fruits in Minas Gerais State. Papaya fruits were collected, in a commercial orchard, in Jaíba, north of the State of Minas Gerais. C. capitata was the only specie collected (794 individuals). Doryctobracon areolatus (Szépligeti) was collected parasitizing C. capitata larvae/pupae. The level of infestation was of 7,7 pupae/kg of fruit or 1,4 pupae/fruit, in average. C. capitata is registered for the first time on papaya fruits in the State of Minas Gerais.
