Adult boxelder bugs [Leptocoris trivittatus (Say)] (Heteroptera: Rhopalidae) were observed feeding on dead conspecifics while overwintering. Boxelder bug adults were collected in the fall of 2000 and 2001 to test the hypothesis that conspecific necrophagy provides a benefit through increased survivorship. Adult bugs were kept individually with no water or food, water only, dead boxelder bugs only, water and dead boxelder bugs, and water and boxelder (Acer negundo L.) seeds. Boxelder bugs kept without water, either with or without other resources, died at a significantly higher rate than bugs kept with water. Bugs provided with water and dead boxelder bugs lived significantly longer than bugs provided only with water and were seen feeding on the dead bugs for up to 2.5 h continuously. The presence of boxelder seeds did not increase survivorship beyond the water-only treatment. It was concluded that water was the most limiting factor determining boxelder bug survivorship during winter, but dead boxelder bugs provided additional resources to further increase survivorship. Conspecific necrophagy in overwintering adult boxelder bugs provides a significant survivorship advantage that could promote this trait in boxelder bug populations.