Dung beetles (Coleoptera: Scarabaeidae) active in patchy forest and pasture habitats in Santa Cruz Province, Bolivia, during spring

The abundance, habitat preferences and flight periods of dung beetles (Coleoptera: Scarabaeidae) in spring was obtained by using cattle dung baited pitfall traps at 4 sites in patchy forest and pasture habitats in Santa Cruz Province, Bolivia. Nine species were trapped in the forest habitat and 4 in the pasture habitat. One species, Onthophagus ptox was trapped in forest and pasture habitats, the other species were stenotopic, found only in forest or only in pasture. Twice as many beetles were attracted to the forest traps but their mean dry weight (biomass/beetle) was 3 times less than the mean dry weight of pasture species. The most important beetles (in terms of biomass) in the forest, Eurysternus caribeus and Ontherus appendiculatus were similar in size and had the same flight periods but their dung utilization methods were different. The most important beetles in the pasture habitat had different flight activities, Gromphas aeruginosa flying during the day and Ontherus sulcator during the night. When forest is cleared, stenotopic forest dung beetles will disappear resulting in reduced species richness. The effect of reduced dung beetle activity in patchy forest could impact on soil structure fertility and water retention making it difficult for reestablishment of the forest.