Found Money

Asking Sandra Marvel about dung beetles is a lot like asking a doting grandma about her grandkids. Marvel will happily spend an hour extolling the virtues of tunnelers, dwellers and rollers. She'll gush over the beauty of these beetles, once considered "sacred scarabs" by the Egyptians. Dung beetles, it seems, have found a spot in Marvel's heart.

How did a nice Florida school teacher get so deep into the subject of dung beetles? It started out five years ago at a county cattleman's meeting, where Marvel and her husband, Daniel, heard a presentation about the benefits of dung beetles. They learned about the negative effects dewormers and pesticides can have on dung beetle populations and that there were people who wanted to buy the beneficials. But no one was selling them.

"We laughed at the idea," she recalls. "You have to dig through manure to find them. My husband and I thought the idea of selling these beetles you find in manure was pretty funny. But the next thing I knew, we were picking up bugs at home and taking them to our state entomologist for identification."

Once assured of a strong population of dung beetles on their High Springs ranch, Marvel called USDA to find out if it would be legal to ship the beneficials. The next thing she knew, her name had been passed on to a zoo biologist in San Antonio, and she was in the dung beetle business.

"The zoos like the big colorful beetles," Marvel said. "I had no idea what to even charge that first time. It's grown from there."

SHIPPING DUNG BEETLES

Today, Marvel's buyers still include zoos, but she's also supplying the occasional graduate student doing research along with several farms and ranches across the country. She ships to all states, but most of her buyers are across the southern part of the U.S. Only California requires a shipping permit, which she keeps current.

There is some debate about moving beetles from one part of the country to another. Florida cattle pastures, for example, have been documented to contain 39 species of dung beetles. Some parasitologists have expressed concern that Marvel's enterprise could introduce a pathogen from one area to another.

"We raise Red Brangus breeding stock and show animals. We've had three national champions. So we've been all over the country dragging a trailer full of cattle behind us. You can take cattle anywhere in this country on a health certificate. Dung beetles will find fresh manure, and they will move with it. I find them in trailers all the time when we're traveling. They can even fly. So I believe these beetles are spread in other ways."

The dung beetles most common to cattle ranches, Onthophagus gazella and Onthophagus taurus, aren't even native to the U.S., Marvel added. They are primarily from Asia and South Africa.

Onthophagus gazella was imported from Australian colonies in 1970 and released in Texas in 1972 for pasture improvement. Onthophagus taurus was accidentally introduced into Florida and first recorded in 1971. It was later intentionally released in several areas, including California, Texas and New Jersey.

"Honestly, I don't feel like I'm sending them anywhere they aren't already part of the population," Marvel contends. She sells both the Onthophagus gazella and the Onthophagus taurus, which are tunnelers.

INCREASING CARRYING CAPACITY

Tunnelers, one of three types of dung beetles, move manure below ground. This makes them highly prized in pastures where they can quicken the dessication and elimination of manure, aerate soil, incorporate nitrogen and ultimately help maximize carrying capacity.

"Cattle won't eat around a manure pat. If it stays on top of the ground and dries, as long as it's there, cattle won't eat around that. You lose about 2 square feet to every pat. In a day, that's 10 square feet per animal," Marvel said. "A good dung beetle population will break down the manure quickly, and within two weeks, cattle are grazing the area."

The beetles she sells for farms and ranches are smaller than a pencil eraser. They are sold in bunches of 400 for $100, 25 cents per beetle. In addition, the buyer pays for overnight shipping. Marvel averages 30 to 40 orders a year, most going to people who raise cattle, horses, llamas or goats. She adds they're not a good idea for chicken farms.

"Chickens just scratch around and eat them, so I don't recommend buying dung beetles for people raising chickens. But they do well with any other livestock."

Buyers should plan ahead when they order beetles with the intent of repopulating areas. Marvel recommends they make sure cattle have not had any chemical dewormers for one to two months prior to releasing beetles. There must be fresh manure for the beetles to get established, as they are not attracted to old pats. In 24 hours, the beetles will move into fresh manure piles and, in the hottest months, can take down a pile in 10 to 12 hours.

"I tell people to just go out at sunset and shake them out around fresh piles wherever you want them. If the cattle move, so will they, because they follow fresh manure."

Marvel does not breed the beetles; she collects everything she sells by hand. This limits what she sells in a year because she doesn't want to damage the population on the family ranch.

SAMPLING FOR BEETLES

For producers who want to sample beetles in their own pastures, Marvel said there are basically two methods. She calls these the "wet" method and the "dry" method. And it's pretty much what it sounds like. Either way, a good bucket, a shovel and some gloves are necessities.

In the wet method, start by looking for little holes around manure, castings of sand in the middle or the edge. Once you find a pile that has these castings (excavated soil that is pushed to the surface underneath or at the edge of the pat), take a shovel and scoop down 1 to 2 inches underneath the pat, and throw it in the bucket. Fill the bucket with water, take a stick and stir, breaking up the piles. The beetles will go to the top and you can pick them out.

"This is probably not my favorite way to sample," Marvel added. "Sometimes they drown."

The dry method of dung beetle sampling is similar but calls for a piece of chicken wire draped in the bucket. The manure pile is put on top of the wire, and, as it's lifted, the bugs will drop down into the bucket.

If you turn over a pile of manure and there are holes in the ground underneath, those are signs of tunneler-type beetles. Dweller types live in the manure. Roller types roll up a ball of manure and move it.

"If you've got beetles, you've got them. You don't need them from me," Marvel added. "If you're worried you might be losing some of your population, look at your deworming program, and consider some changes to when you deworm, what method you use or what class of chemical you're using.

"We have a wonderful population of dung beetles here. I think one reason is that we've rotated different classes of chemicals; plus, we only [deworm] parts of our herd at a time," she says of their 50 head of registered Red Brangus cattle.

CREATE A BALANCE

Marvel said they don't generally use anything for fly control because they fear it will negatively impact dung beetles during those hot, summer months. She and her husband watch fly levels, generally aiming to keep face flies under a count of 15 per animal. They don't use ear tags, and only occasionally spot-treat for flies on show cattle. Horn flies are not a problem here because of the dung beetles' fast work.

While a good population of dung beetles is a priority, it doesn't come at the expense of herd health. Marvel said they deworm their herd using ivermectin in the winter and Cydectin in the spring, summer and fall. During the winter months, dung beetles aren't active. She said temperatures need to be in the high 60s and 70s to start seeing beetle activity. So their deworming program is planned around the seasons. As is Marvel's part-time job.

"I hear that I'm the only one in the U.S. selling the common beetles," she said.

"I didn't set out to be the only one. I just guess I was willing to dig, trap and collect, and figure out how to sell them to people in a cost-effective way. Anybody can do it though.

"Really, I just find it fascinating. They're beautiful, and thanks to them, I've met people all over the country who are as interested in dung beetles as I am."

Editors Note: For more information on Sandra Marvel's dung beetle sales, visit dungbeetles.biz, or email MarvelFarms@windstream.net.

DIRTY JOBS

On a cattle operation, manure management has to be considered a priority for the overall health of both animals and forages. A healthy population of dung beetles can be a tremendous, and often unseen, asset, veterinarian David Pugh said.

Board certified in veterinary parasitology, Pugh has a master's in entomology and is head of the Alabama state diagnostic lab system. He said there are more than 90 species of dung beetles in North America, with fewer than 12 significant in the recycling of manure. Those break into three types: rollers, dwellers and tunnelers.

Dung beetles seek out fresh manure, which is always in ample supply on a cattle ranch. Pugh said a 650-pound animal produces about 60 pounds of manure daily (wet). During the course of a year, that one animal would produce more than 10 tons of manure. The beetles go from egg to larvae to pupae to adult. They consume, bury, breed and lay eggs in dung. Some research estimates they save ranchers $380 million annually by recycling nutrients from manure onto pastures.

"Basically, dung beetles enhance productivity and increase pasture quality," Pugh said. Here's how they add to the bottom line:

-- Higher carrying capacity. Researchers have shown a 25% to 30% increase in a pasture's carrying capacity due to a healthy, active population of dung beetles. Pugh said in three to seven days, dung beetles can break down a cow patty. Undegraded manure reduces carrying capacity by smothering forage and creating an area around the pat not grazed for as long as two years. A healthy population of dung beetles allows cattle to be grazing that area again more quickly -- in most cases less than two weeks.

-- Increased nitrogen incorporation. Manure that doesn't break down loses about 80% of the nitrogen that could be incorporated into soil. Dung beetles break down manure quickly, making that nitrogen available. Dung beetles have been shown to bury up to 78% of cow manure. Their presence improved coastal bermudagrass yields by 22% in one study, the equivalent of what would be expected from applying 200 pounds of nitrogen per acre.

-- Natural soil aeration and higher water retention. Tunnelers carry manure into the soil and create aeration with their labyrinth of tunnels, improving water retention. In an Oklahoma study, water permeability into the soil was 129% deeper in the presence of dung beetles.

-- Fewer flies and nematodes. Dung beetles are considered a biocontrol agent, especially when it comes to horn flies. Research confirms a healthy population of dung beetles can reduce emerging horn flies by 95%. Nematode populations on pasture foliages were 55% to 93% lower in the presence of the beetles.

SAVE THE DUNG BEETLE

The dung beetle isn't immune to chemicals found in most insecticides and dewormers. These products pass through the animal, and when dung beetles come into contact with them, their levels can be negatively affected.

Macrocyclic lactones are one class of chemical that can have adverse effects on dung beetle larvae. Studies have shown mortality of larvae that came into contact with the dung of treated cattle, several days to several weeks posttreatment with avermectins. This can reduce breeding capacity of future generations of many dung beetle species.

Moxidectin, also a macrocyclic lactone, has shown less of a negative impact on dung beetle mortality in research studies, even when shed at higher levels than avermectins.

Jody Wade, senior veterinary consultant with Boehringer Ingelheim, encourages producers to get informed about the value of dung beetles and check their on-farm populations.

"If you use enough of anything, even the moxidectin, you will probably see some negative effects on dung beetle populations," he said. "The key to good management is to treat at label rates based on weight of the cattle."

He added that the convenience of pour-on dewormers or even fly controls can make overdosing more of a risk. Pour-ons, he said, aren't just taken in through an animal's skin but are also ingested as the cattle lick product off.

Veterinarian David Pugh said it's important to seek the right balance. A heavy fly or worm population, for example, probably does more harm to cattle than having too low of a dung beetle population.

"But if you can control worms, have a low fly population and, at the same time, maintain a healthy dung beetle population, isn't that the balance we're trying to strike?"

Pugh isn't a big proponent of buying dung beetles. He said judicious use of insecticides and dewormers will allow most producers to rebuild their native beetle populations without resorting to bringing in a new supply.

"I honestly don't think I've ever seen a place without any dung beetles," he said. "There may be some, but I haven't seen them. I believe this is a case where the more you know, the better job you can do to keep these beetle populations strong. Awareness is what we're talking about."

(VM/CZ)

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