Food Discrimination and Ovarian Development in Burying Beetles (Coleoptera: Silphidae: Nicrophorus)

Burying beetles are carrion feeders that reproduce on small carcasses, but adults are also attracted to large carcasses to feed themselves. Beetles captured at large carcasses (baits in pitfall traps) and small carcasses (mice placed singly on the forest floor) differ in their mean ovary weights. Beetles with mature ovaries tend to favor the mice, whereas newly emerged adults with immature ovaries tend to favor the pitfall traps. The ovaries of all beetles develop only to a certain point; final oöcyte development proceeds only after a small carcass is secured. Because our baited pitfall traps represent an adult food source, they capture a biased sample of the community, a sample that underrepresents the most reproductively active individuals.