Endangered Beetle Gets Help From Zoo
September 12, 2004
If insects had their own reality dating shows, the American burying beetle would make one of the strangest stories to hit the antennae waves:
Contestants would be lured to an exotic locale by the pungent smell of a decaying animal. After flying up to four miles to reach their destination, various adults lock pinchers in a battle to seize control of the carcass, perhaps a dead rabbit or bird.
The winning male and female pair, in a stunning display of strength, carry off the cadaver and bury it. There, the victorious couple embalm the corpse with anal and oral secretions.
In their subterranean trophy room, the bugs mate, lay their eggs, and then feed their larvae from the carcass they've preserved. If there's not enough food, the parents eat some of their offspring to make sure there is enough food for the others.
It's a match made in . . . well, if not in heaven, then somewhere about a foot underground.
Jane Stevens hopes to duplicate some of the action in her laboratory at the St. Louis Zoo. As curator of invertebrates, she runs a new captive breeding program for the endangered beetle. Stevens jokingly calls it her "beetle brothel."
Zookeepers captured 13 American burying beetles in a patch of Arkansas prairie this summer. If all goes as planned, these large, black-and-orange beetles will propagate dozens more insects in the months ahead.
"Aren't they the most beautiful thing you've ever seen?" Stevens asked, taking a female out of its plastic cage. "I'm in love. I don't know how else to say it."
Larvae get TLC
The insects' reproductive habits are helpful to the ecosystem. Like other carrion eaters, the beetles are nature's garbage men, sweeping up biological trash and recycling it into a useful form.
"There would be a lot of stinky dead stuff lying around if there weren't these guys going around breaking it down," Stevens said. "There's this wonderful cycle these guys help keep going."
Stevens is also impressed with the beetles' parenting abilities. They regurgitate digested meat for their larvae, who beg for food like baby birds. "It's amazing, the beauty of the beast," she said. "Most insects just lay their eggs, then they're gone. The parental care is amazing."
The American burying beetle once flourished in 35 central and northern states. By the time the beetle was listed as an endangered species in 1989, Rhode Island had the only known population. Scientists suspect that habitat loss and a lack of suitable carrion is killing off the insect, which can grow to almost 2 inches long.
The beetle has since been discovered in six more states, including four that border Missouri - Arkansas, Kansas, Nebraska and Oklahoma. Stevens and her staff have shaken down hills and vales through Missouri for three years so far, and they plan to keep looking.
"You know it's got to be in Missouri," she said. "As obsessive as I am, I'm going to find it."
Sweat and stench
Discovering the beetle anywhere isn't easy. Even at the Arkansas site, where the beetles were known to be lurking, it took a lot of hunting to get a single specimen.
On a recent trip, senior keeper Tim O'Sullivan laid baited traps by day. At night, he rigged up sheets illuminated by a black light that attracts insects. After four days of searching in temperatures that topped 103 degrees, he finally got one.
"I was exhausted. It was the very last trap I had to check," O'Sullivan said. "I thought, good, I can go back to the hotel and take a shower. I opened the trap, and there it was."
The Zoo's extra-smelly bait recipe may have helped. O'Sullivan said the rancid stench created by raw chicken meat left in the sun in a jar of water for three days is "hard to get out of your nose."
"We've had gagging episodes, all of the guys," Stevens said.
For Stevens, anyway, it's a worthwhile price to pay to capture the rare insect. The Zoo has a permit from the U.S. Fish and Wildlife Service to collect 30 breeding pairs. The collection may be supplemented with captive-bred beetles from Ohio State University, she said.
Eventually, the federal government may authorize the Zoo to release some of its beetles into the wild. But first, there have to be babies - and lots of them.
The Zoo's very first attempt to breed a pair didn't go so well. Last week, Stevens took a male and a female out of their separate cages and placed them into a five-gallon plastic bucket that had been filled with crumbly soil. A dead quail lay on top of the soil.
"The male started squawking and screaming and he mated her on the spot. I was yelling, 'He's mating with her!' Everyone came running over. They circled the bucket a few times. Next thing you know, they were buried," Stevens said.
The whole thing lasted just a few seconds. "It's not like they have to have dinner and a movie," Stevens joked.
The staff respectfully put the lid on the bucket and gave the beetles some private time. They hoped the pair would bury the quail overnight and bring up a brood of larvae.
Only thing is, it didn't work. "They never buried it," a disappointed Stevens said a few days later. "We think we may have gotten newly hatched young. It takes about a month after they emerge to be reproductively ready."
Stevens is giving the teenagers a few more weeks to mature. Meanwhile, she can pair up some of the other beetles captured by keepers Danny Koch and Bill Borchardt.
Like a doting grandmother, Stevens has visions of a big extended family. Each female can lay up to 30 eggs at a time, and she can be bred several times during her one-year life span.
"If we could have that kind of reproduction going on, my goodness, we could have a lot of beetles here before long," Stevens said.
Republished with the permission of the St. Louis Post-Dispatch.
Copyright 2004 St. Louis Post-Dispatch
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