Temporal dynamics of diversity in a tropical fruit fly (Tephritidae) ensemble and their implications on pest management and biodiversity conservation

Abstract

The fact that pests are the most abundant species in agricultural settings has broadly precluded the attention to non-pest species and the study of temporal dynamics of diversity in agroecosystems. Because, agroecosystems hold increasingly important portions of biological diversity, understanding of non-pest species dynamics in such systems will contribute significantly to their conservation. In addition, deep understanding of both pest and non-pest population dynamics in a community context necessarily requires a long-term approach. By means of the analysis of weekly fruit fly sampling sessions across 12 years, in three tropical fruit orchards, we describe the temporal dynamics of species richness and turnover, structure and composition of Anastrepha fruit fly ensembles considering pest and non-pest species. Furthermore, we ask if time series of non-pest species covariate with time series of pest species, as a way to evaluate the best management scheme to minimize negative impacts of pest control on non-pest species. Among 18 Anastrepha fruit fly species detected over 12 years, five were considered as pest species. Fruit fly ensembles were characterized by strong seasonal dynamics composed of annual cycles. Sapodilla was the most diverse orchard. Overall, fruit fly ensembles appeared stable throughout time. The temporal dynamics of non-pest species covaried positively with temporal dynamics of pest abundance, with consequent management implications. Results suggest that in mango and grapefruit orchards, pest control could be focused during time periods with low potential impact on non-pest species; while in sapodilla orchards other approaches should be developed. The approach described here could be used in agroecosystems to minimize the impact of pest management on non-pest species particularly in highly anthropized landscapes and human-managed ecosystems were biodiversity conservation is a high priority.