Coprophilous arthropod community from Argentina with species of potential use as biocontrol agents against pest flies

Dung-inhabiting pest flies are one of the main problems associated with the accumulation of cattle dung. This work analyzes the diversity and dynamics of a coprophilous community from northern Buenos Aires, Argentina, in a search for potential biocontrol agents. Thirty-six dung pads of 3 age categories and 4 microhabitats were collected on each sampling date and examined for their arthropod fauna. Some of the species with undefined feeding behavior were subjected to feeding trials in the laboratory. We found 34 coprophagous species, 47 predators, and 13 parasitoids. The combination of the results of the feeding trials, co-occurrence and abundance data of the prey and predator populations, and direct field observations were used to put together a trophic web and hypothesis on the dynamics of the community. Dung scarabs cause significant reductions in immature dung fly survival by burying and desiccating large amounts of dung. The Philonthini (Coleoptera: Staphylinidae) are the most abundant and rich predator group, although they are slow to respond to variations in fly populations. However, predatory flies show the same abundance curves as their prey flies. Predatory beetles and flies, dung scarabs, and pupal parasitoids cause additive mortality to the fly population, whereas larval parasitoids cause some compensatory mortality. Four species of staphylinids, 1 predatory muscid, and a coprophagous scarab could have potential as biocontrol agents. The perspectives of success and convenience of a horn fly biocontrol scheme in southern South America are discussed.