Dung Beetle Ecology: Habitat and Food Preference, Hypoxia Tolerance, and Genetic Variation

Dung beetles (Coleoptera: Scarabaeidae) play a major role in nutrient cycling, soil aeration, and the biological control of pests and parasites that breed in manure. Habitat fragmentation, pesticide usage, and conventional agricultural practices are threats to dung beetle diversity, and their conservation is of growing concern. Comparison of organic and conventional ranching practices is of great ecological and economic value to the agricultural industry in the Great Plains region of North America. Using baited pitfall traps, this study compared abundance, diversity, and seasonal activity of dung beetles on adjacent rangelands in western Nebraska that are certified organic or managed conventionally. Numbers and diversity of dung beetles were much higher on organically managed rangeland. The organic ranch accounted for 53% of total dung beetle capture with 3,287 total dung beetles, while the area between ranches yielded 40% (2,480 dung beetles). Only 480 dung beetles (8% of the total capture) were collected from the conventionally managed ranch. A total of 15 species were captured, and all commonly collected species (> 50 individuals) were found in higher numbers on the organic ranch (p < 0.05). Based on these results, organic ranching in a short grass prairie ecosystem preserves and increases the number of dung beetles compared to conventional ranching practices in a similar habitat.