HAMILTON, Ohio -- An endangered species of insect is getting a second chance to call the Tri-State region home thanks to a combined effort by the Ohio Division of Wildlife, the Cincinnati Zoo & Botanical Garden, The Wilds and Ohio State University.
The last week in May, members of the group assembled at Fernald Nature Preserve to deposit nearly 300 American burying beetles, or ABB, beneath the soil in order to help reintroduce the species. In addition to the 110 breeding pairs, 50 single lady beetles were added to increase chances for successful breeding.
Once abundant in the U.S., the species can now be found only in Arkansas, Nebraska and Oklahoma.
Averaging about an inch and a half long, the ABB sports brightly colored markings along with orange pompom antennae. The Cincinnati Zoo’s head insect keeper, Mandy Pritchard, said the insects play an important role in terms of decomposition as they bury small dead animals then rear their young in the carrion.
“Decomposers play a huge role in our ecosystem, as they’re finding carcasses and burying them underground,” she said. “So they’re preventing explosions of fly populations, they’re also getting rid of dead stuff and recycling the nutrients back into the soil and the environment. So they are actually very important.”
As part of the reintroduction process at Fernald, the team gathered in a wooded glen to dig multiple 6- to 8-inch-deep holes. In order to create romantically ideal conditions for breeding, a rat carcass was placed in each hole along with a mating pair. The team then covered the holes with dirt and layers of fencing to discourage scavengers.
“The beetles can produce anywhere from one to dozens of larvae,” Pritchard said. “I think the most I’ve ever found was 47 living on one brood ball, so they’re capable of producing tons of offspring.”
To produce ABBs for the release, the zoo used a similar process at its facility indoors using 5-gallon buckets. In addition to zoo staff, members of the Zoo Academy – made up of juniors and seniors from Hughes High School – helped rear the young beetles. Junior Vallie Congrove said she learned so much from the experience including a new appreciation for this particular species.
“It’s really important they bring them back because they do a very important job,” she said. “Everyone who is working on the project is super dedicated, and it’s really sweet that they’re all doing this.”
But despite their ongoing efforts, tracking success has been difficult, Pritchard said. Even though they see successful breeding, the next year the ABBs are no longer on site. She said one theory is the beetles are relocating to other areas.
“We’re trying to figure out where they’re going,” she said. “They can fly up to two miles a night and they’re very attracted to porch lights, so all the light pollution turns out to be an issue for them. We’re confident they’re reproducing because I’ve seen it, but as far as dispersing I think they’re going a little bit farther than we anticipated.”
Since being declared an endangered species in 1989, the U.S. Fish and Wildlife Service has actively been trying to increase numbers. In 1998, the Ohio division began releasing small numbers of ABBs in a wildlife area in southeast Ohio, then shifted the release site to Wayne National Forest from 2008 until 2012.
“During this period of time, OSU discontinued their breeding program and the Cincinnati Zoo and The Wilds both initiated breeding programs,” Ohio Fish and Wildlife endangered species biologist Amanda Boyer said. “We started releases at The Wilds in 2011 and have done them there annually. The Fernald releases started in 2013.”
This year at Fernald, Boyer got her share of exercise using a golf-hole cutter to penetrate the semi-dry ground. To date, Boyer said she’s participated in every release. She said in terms of survival, they also speculate the ABBs may not be faring well in the colder months.
“We’ve changed the source location for our brood stock from Arkansas ABBs to Nebraska ABBs in the last couple years,” she said. “We believe that using ABBs from a more northern source may help to ensure overwinter survival. The Nebraska ABBs overwinter deeper underground, which may give them an advantage in surviving Ohio winters. We’re hopeful that this may be the key to successfully restoring a wild ABB population in Ohio.”
In the 1800s, the American burying beetle (ABB) flourished throughout the United States. During the turn of the century, the species began disappearing in North America with the exception of a handful of states.
“There’s a lot of theories about why they disappeared, but I think the overall accepted belief is it’s not one or two things, it’s a combination of things like habitat loss, habitat fragmentation,” Pritchard said.
“They also think the extinction of the passenger pigeon as a major food source played a huge role in it as well.”
Boyer said that since 1620, more than 500 species, subspecies and varieties of our nation's plants and animals have become extinct. She said reintroduction efforts like that being done with the ABBs are important to the health of the planet.
"This species is part of the natural ecosystem and may serve other important roles that we are not even yet even aware of,” she said. “Also, re-establishing this species into its historical range will also help to recover the species.”
During the first week of June, Pritchard revisited the site to check results. She said she’s encouraged by the following:
- Checked 31 broods total.
- 16 had larvae present.
- Average brood size of 10.8 larvae
- 52% success rate.
- 109 total paired broods.
- Overall produced an estimated 613 larvae
Single female broods:
- Checked 14 broods total
- Four had larvae present.
- Average brood size of seven larvae
- 29% success rate
- 57 total single female broods
- Overall produced an estimated 116 larvae
Total larvae count for this release is 729.