American Carrion Beetle
The American Carrion Beetle (Necrophila americana) belongs to a family of carrion beetles called Silphidae. It feeds primarily on decaying plants and animals, in both the adult and larval stage of its life cycle. It will also sometimes feed on fungi or rotten fruit, and so can often be found in or near compost bins. Both the larvae and the adults will also feed on other fly and beetle larvae that are trying to take advantage of the same food source. The eggs are laid in the food source itself, and upon hatching, the larvae start to feed on both the primary food source (animal carcass, rotten fruit, etc.) as well as other larvae it may encounter. Once mature, the larvae fall to the ground, then dig into the soil in order to pupate.
The amount of time from larva to adult is about three months. The adults prefer moist habitats, and are active from spring through fall (but particularly in really warm weather). They go through just one generation per year, and overwinter as adults. They are very beneficial because of their role in assisting with decomposition.
Additional Information and Photos: American Carrion Beetle (BugGuide.net)