A carrion beetle continues its important work of recycling dead things.
Through no fault of their own, white-tailed deer are a major pest of ornamental plants in our suburban and rural landscapes. It is estimated that in the US, more than 20 million deer share the land with us. When I see a dozen or so bedding down in my backyard, I think most of them live in Columbia, Maryland. Long gone are the wild predators, mountain lions and wolves, that once kept burgeoning deer populations in check. Encroachment of human development on natural habitats put deer in contact with humans and their gardens. The grazing pressure of deer in my neighborhood has defeated all attempts at growing unprotected vegetables. During the winter, my pansies were pillaged and my once glorious azaleas were reduced to skeletal pickets of denuded branches presenting a few sad blossoms this spring. Small saplings bear the scars and deformities dealt by young bucks removing velvet from their antlers. The growing tips of my hopeful sassafras and ceanothus are but a memory. With all the undesirable changes deer bring to the suburban landscape, what is the upside of this pariah?
I found one answer to this question last week while walking in a field not far from a roadway traversing Etchison, Maryland. Resting in the tall grass near a forest edge were the remains of a white-tailed deer, no doubt the unfortunate participant in recent encounter with a vehicle on the nearby road. Upon closer inspection, I discovered a well-developed ecosystem of necrophagous insects making the most of the decaying bounty provided by the deer in its final act. Among the most prominent and abundant of these flesh eaters was Oiceoptoma noveboracense, known in some circles as the margined carrion beetle. Along with flies and other species of beetles, carrion beetles provide an important ecosystem service by recycling the protein found in the flesh of dead animals. Carrion beetles are not usually the first to arrive at the carcass of a dead thing. This honor belongs to blowflies which often discover a body within minutes of its demise. Once colonized by blowflies, a dead animal will soon be writhing with maggots of flesh-eating flies. Maggots are an important source of food for adult carrion beetles, including Oiceoptoma noveboracense. As they graze on the bounty, adults deposit eggs in the soil near the carcass. Eggs soon hatch into larvae.
During the courtship ritual of Oiceoptoma noveboracense there’s a whole lot of shaking going on.
Carrion beetle larvae are champions at consuming shreds of protein-rich flesh and internal organs of the deceased. By the time I happened across the deer, hundreds of beetle larvae were enjoying sustenance and shelter from the helpful deer. After feeding as larvae and molting several times, larvae move to the soil to pupate. A bit later in summer, fresh adults will emerge from the soil and await the arrival of dead things next spring. Due to their affinity for certain types of habitats, their seasonal appearance, and geographic distribution, Oiceoptoma noveboracense can be useful in helping crime scene investigators solve homicides. This uplifting encounter with the white-tailed deer provided some succor to the ill will engendered by these habitat destroying herbivores. To bring more crime solving beetles into the world is surely a noble deed for the oft maligned white-tailed deer.
A closer look at a deceased white-tailed deer revealed hundreds of carrion beetle larvae dining on the worldly remains of the helpful dead.
References
Many thanks go to Kelly, who was this inspiration for this episode of Bug of the Week, for allowing me to wander his fields in search of wildlife. The delightful reference “The carrion beetles (Coleoptera: Silphidae) of Nebraska” by Brett Radcliffe was used as a resource for this episode.