DODGEVILLE, Wis. – 1dr Acres Farm near Dodgeville, managed by Cherrie Nolden and Allen Philo, has 50 acres on the home farm along with 80 acres of additional forest. The two rotationally graze goats, horses, beef, sheep, pigs and poultry – all protected by guardian dogs that allow them to keep the animals on-pasture year-round. They use continuous perennial cover and holistic planned grazing with multiple species along with properly timed conventional fertility applications. The farm is surrounded by buffers of tall vegetation that intercept water and nutrients.
All that allows them to manage for different varieties of dung beetles – farm critters that work for free.
Cherrie Nolden, a doctoral candidate in animal and dairy science at the University of Wisconsin-Madison, said the farm was a corn field when she purchased it and converted it to perennial pasture. By managing the farm using holistic planned grazing and minimal de-worming they are able to attract and maintain a population of existing dung beetles. Of the three types of dung beetles – dwellers, tunnelers and rollers – she has tunnelers and dwellers.
Collecting dung beetles from manure samples on a farm involves grabbing a manure pat, sticking it in a bucket of water and waiting as the dung beetles float up.
“With management that promotes dung beetles you get improved soil-nutrient cycling, better soil structure, increased forage production and water infiltration,” Nolden said. “They’re very beneficial when we manage for them.”
Management practices such as avoiding macrocyclic lactones found in de-wormers, which cause dung-beetle larvae to die, help the population thrive, she said. So she de-worms in winter.
Because the dweller species of dung beetles spend their entire life cycle in manure pats, they’re aided by manure being left in pastures undisturbed for the four to six weeks it takes for dweller larvae to emerge as adults.
“If you have a shorter rotation length than that, having the same species come through the paddock works because they naturally avoid their own manure,” she said.
A tunneling species, Onthophagus Hecate, is prolific on the farm. She said it’s good for soil health because it takes manure and buries it below the pat in the soil, while bringing soil up to the surface. That improves soil aeration. The Onthophagus hecate likely has two generations per summer.
“It lays its egg in each little dung ball that it buries,” Nolden said.
Any farm that manages for them should be able to have them thrive and be able to benefit from beetle activities, she said.
Nadine Kriska, a professor of biology at UW-Whitewater, is a beetle taxonomist with a background in Wisconsin scarab beetles. There are several different types of dung beetles found in Wisconsin, she said. Wisconsin is a unique state because of the area referred to as the tension zone in mid-Wisconsin. The area has flora and fauna that are in the northernmost and southernmost zone for numerous species of plants and animals. There are native species consisting of the three dung-beetle types – rollers, tunnelers and dwellers – but there are also non-native species of European origin, many of which are dwellers along with a few tunnelers.
“We don’t get a lot of rollers; perhaps five roller species occur here and they’re not in very large numbers,” she said.
Dwellers and tunnelers occur in Wisconsin pastures. Because of Wisconsin’s cold winters there isn’t any dung-beetle activity in winter months. In contrast southern dung beetles are active year round, she said. Wisconsin has less turnover with the breakdown of cow patties even during the spring through fall months compared to the south.
Wisconsin’s dung beetles found in pastures are “generalists,” Kriska said. They utilize the dung from whatever livestock are present. But pig dung is especially useful for baited pitfall traps, which are used to catch and identify dung beetles. A trap is a plastic cup placed in the ground with the lip flush to the ground surface. By adding a container of pig dung to a cup hovering over the lower cup, one can monitor what falls in the cup during a period of a few days.
“For some reason dung beetles are really into that pig dung from what I’ve seen in my trapping,” she said. “(But) for a lot of native dung beetles that we have in Wisconsin we find them specific to deer dung or owl pellets.”
And some will only be present in squirrel nests.
In Wisconsin pasture species there’s a lot of smaller dwellers that spend their entire lives at the interface between the patty and the ground. Tunnelers make their tunnels directly below the patty, as deep as a foot.
“With the tunnelers in particular they’re important in overturning the soil and mixing nutrients as well as bringing those things down to feed their larvae,” Kriska said.
Nolden and Kriska spoke as part of a Michael Fields Agricultural Institute virtual field day, “Dung Beetles – Free Labor for Healthy Pastures & Clean Water,” supported by the UW-Division of Extension and the Wisconsin Department of Agriculture, Trade and Consumer Protection. Visit michaelfields.org for more information.
Greg Galbraith, a former dairy farmer who owns woodlot property in eastern Marathon County, Wisconsin, writes about the rapidly changing nature of the agricultural landscape. He has built a lifetime connection to the land and those who farm it.