Preventing the Apocalypse with the American Carrion Beetle

Source: University of Wisconsin-Milwaukee

You may be asking yourself– as any reasonable person would– what is our greatest defense against a zombie outbreak this Halloween? The nutrient cycle may be the answer. Detritivores, such as the native American carrion beetle, ensure the dead return to the earth as part of this never ending process. Also known as the American burying beetle or Necrophila americana, the beetles emerge at night in the warm months after a long underground hibernation. You may have stumbled across these shiny, black and yellow insects and thought “bumblebee,” but upon closer inspection realized they were working on a (subjectively) less appetizing meal than honey. The diet of both adults and larvae consists of decaying plants and animals, though they will also consume other larvae, fungi, and rotting fruit.

Source: US Geological Survey

The nutrient cycle moves through both biotic (animals, plants, fungi, and bacteria) and abiotic (soil, nonliving organic matter, air, and water) parts of the ecosystem. Decomposition is a key stage, releasing carbon dioxide and nutrients from complex organic matter. After a plant or animal dies, decomposition occurs in three steps: leaching, fragmentation, and chemical breakdown. First, water removes loosely held compounds such as sugars and free amino acids from the organism. The American carrion beetle enters in the second step, in which animals that feed on detritus (dead organic matter) further break down fragments to prepare them for microbial colonization. Microbes in the soil complete the process by transforming and trapping nutrients. Unfortunately for our zombie theory, decomposition does not encourage organic matter to stay put in the ground. However, the matter has entirely changed forms; what was once a deceased squirrel, for example, is now a menagerie of nutrients including carbon, hydrogen, oxygen, and mineral elements which will be taken up by living organisms and soil. Trees and other plants use their roots to take mineral and non-mineral nutrients to store them in leaves and flowers. They will return to the soil or be eaten by animals, which will eventually die and decompose– and thus the cycle continues.

To prevent a strain of undead white-tailed deer with a hankering for brains– or just to maintain a healthy ecosystem– the nutrient cycle must remain in equilibrium. The American carrion beetle is just one piece of the puzzle, but their role is immensely important to our survival. Their native habitat in the US encompasses 35 states, and they are known as generalists which can survive in a variety of environments. However, they are critically endangered due to habitat loss from agriculture, rising temperatures, and urbanization. This Halloween season, we should take a moment to thank the remaining Necrophila americana and keep them in mind while planting trees,  tending our gardens, and woefully driving past roadkill on the interstate.

This article was written by Forest Projects Field Specialist, Jerilyn Lapp.