Community Dynamics of Carrion Flies and their Parasitoids in Experimental Carcasses in Central Argentina

Insects are the predominant group regarding both species richness and abundance that develop on carrion. Among them, the most important decomposers using carrion as a source of food for their development are the immature stages of the dipteran families Calliphoridae, Muscidae, and Sarcophagidae. The large numbers of their larvae in carcasses are attacked by a rich community of parasitoids, including species of Braconidae, Ichneumonidae, and Pteromalidae (Hymenoptera: Parasitica). The objective of this study was describing the temporal composition and dynamics of a parasitoid community in relation to their dipterans hosts in carrion in terms of number of species and specific composition, irrespective of the particular interactions between species in both trophic levels. Additionally, seasonality of the climate in the region was investigated as a factor structuring the studied communities. The experiments were undertaken in the south of Cordoba, Argentina during 2004 in a rural area. Two traps per season were placed separately approximately 300 m from each other in the study site. Each trap contained a domestic pig (Sus scrofa) of approximately 8 kg as bait. Samples were taken daily during the first four weeks and then every two or three days over the following weeks until the end of the experiment. The dipteran community was represented by 15 species in 6 families of the Calyptratae Diptera whereas parasitoids belonged to six families of the parasitic Apocrita Hymenoptera. Climatic seasonality was an important factor in determining the number of occurring species in the carcasses and community composition. The highest number of species was observed in the spring for both communities.