Does the body size of tachinidae parasitoid flies (diptera) change in the dry chaco landscape of Tucumán?

Abstract

The configuration and composition of the natural or anthropic landscape are related to biodiversity patterns and ecosystem services, such as the control of herbivores. Changes in the landscape determine changes in biotic communities, including the diversity and composition of animal body sizes. In this study, our objective was to examine the differences in body sizes of tachinid parasitoid flies between agricultural, natural, and mixed plots of 1 ha in an area of Trancas, Tucumán. In addition, we explored the wing / thorax ratio of flies among plot types. We measured flies of all species collected using Malaise traps in the study area (n = 90). We characterized the landscape from satellite images and analyzed the data using ANOVA. On average thorax width measured 2.35 mm (SD = 0.87) and wing length measured 5.67 mm (SD = 2.06). Both thorax and wing were less variable in natural plots than in mixed plots and in agricultural plots (thorax: F = 2.864, df = 2, p = 0.06, wing: F = 2.388, df = 2, p = 0.09). The wing / thorax ratio did not vary among the plots, suggesting that functionally the fly communities do not change (F = 0.6231, df = 2, p = 0.5387). We now measure more individuals and examine both the diversity and composition of fly sizes in the plots and take detailed metrics of the landscape to relate them to fly sizes. Studying body sizes at the community level will allow us to determine the value of this variable to describe the structure of herbivore controlling communities in regions of the world where there are still undescribed species.