Why Dung Beetles Are the Unsung Heroes of Nature

Left to its own devices, nature is very good at recycling. Nothing is ever wasted. Everything can be used again and can be useful for some organism or some purpose in a timely manner. That includes poop. To make this system work, nature needs expert recyclers. These are organisms that take a waste product and turn it into something that is useful or available for other forms of life. When it comes to poop, the dung beetles are master recyclers, and their abilities and importance to ecosystems are extraordinary. Their lives are surprisingly complex and impressive. Let’s find out more.

The Lowdown on Dung Beetles

There is no single species of dung beetle. It is a collective term to describe beetles that use the manure of animals. We know of at least 8,000 species of dung beetles, and they can be found on all continents except Antarctica. Most can fly, and they are a variety of colors ranging from glossy black to metallic green. Some can look quite fierce with horn-like structures on their heads. Their length can be anything from 0.5 inches to 2.5 inches, depending on the species.

What Do Dung Beetles Do With Dung?

This is where things start to get a bit more complicated. Dung beetles can be broadly divided into three groups depending on how they behave when they find a dung pile. Here they are:

Rollers (Telecoprids)

The best known are the ‘tumble bugs’ or ‘rollers’. Males and females pair up after a male has offered a female a huge ‘brood ball’ of poop. If she accepts it, they roll it away together. Sometimes, the male rolls the ball while the female rides on top. They may also have to fend off other beetles trying to steal their dung ball! He heads off to find another partner, but she stays and makes another ball or two and then lays a single egg in each one. She seals the balls with a mixture of dung, saliva, and her own poop and buries them.

Tunnelers (Paracoprids)

The second group is the ‘tunnelers’. They draw manure from the main deposit down into the soil. They build nests in the soil under a dung pat where they raise their young. If you find piles of soil next to the dung pat, it indicates that tunnelers are in action! Tunnelers and tumblers are classified as “nesters” because they are preparing a home for their young. By storing the dung underground, they keep it fresh and away from grubs and parasites.

Dwellers (Endocoprids)

Finally, the ‘dwellers’ live within the manure pit itself. They lay their eggs on top of it, and their offspring develop in it. They are smaller than rollers and tunnelers and have a preference for the fresher cow pats.

Locating and Working on a Dung Pat

Most dung beetles are looking for the manure of herbivores because they excrete a lot of undigested food in their poop. It’s basically a pile of undigested grass and smelly liquid. There are a few species that live in and on the poop of carnivores, and some would prefer mushrooms, carrion, and decaying fruit.

When it comes to habitat, they are found in the same areas as the animals that produce the dung. So, you will find them in forests, grasslands, prairies, and deserts as well as on farmland. They detect a dung pat using their specialized antennae. It is essential that they get there quickly because a dried-out dung pat is of no use to them. They feed on the liquid dung using their specialized mouth parts, so once it dries, they can’t suck out the nutritious (if disgusting) liquid.

Incredible Strength

Living on and around poop is not the only remarkable thing about dung beetles. They are also incredibly strong – and there have been scientific experiments to prove it. Laboratory tests on a range of insects have shown that the horned dung beetle (Onthophagus Taurus) can pull 1,141 times its own body weight. This makes them the strongest insects on the planet. This is the same as a fairly average adult human (weighing 154 pounds) pulling 80 tonnes, which is roughly equivalent to six or seven double-decker buses!

This amazing strength has not evolved for hauling dung. It is connected to the way males compete for females. If an imposter male tries to enter a tunnel already occupied by a rival, he will be physically pushed back out. The stronger beetles get to defend their tunnels more successfully.

Their strength is attributed to the mechanical properties of their leg joints. The structure of these joints spreads the force applied to them to the exoskeleton of the femur, thereby protecting the leg joints from damage.

Conservationists Love Dung Beetles

Conservationists love dung beetles because they play a key role in the ecosystem. They accelerate decomposition, making the nutrients in dung available quicker because they carry the dung down into the soil. For example, the presence of dwellers in an area has been shown to increase phosphorus levels in the soil by 50 percent.

They also improve nutrient recycling and benefit both the physical and chemical properties of soil. This also improves water infiltration. Dung beetles are most commonly found in sandy soils, warmer climates, and at lower elevations. In areas where cattle graze, there are more dung beetles and a wider range of species. These beetles are more efficient and effective at their role when there are a lot of them and there is a rich diversity of species.

The Benefits of Dung Beetles for Farmers

Dung beetles bring great benefits to livestock pasture. In addition to the improvements in soil nutrients described above, they also help reduce the number of pests and improve forage availability.

Reduction of Nematodes and Flies

Both horn flies (Haematobia irritans) and face flies (Musca autumnalis) are economically important pests of cattle. Around 60 to 80 horn flies can be generated from a single cow pat. Horn flies bite and feed on the blood of cattle. This is not just annoying for them; it also causes blood loss and can lead to weight loss. In dairy cattle, this can lead to a 10 to 20 percent loss in milk production. To make matters worse, horn flies can also carry parasites (Stephanofilariasis), which cause dermatitis along the underside (ventral midline) of cattle. Face flies do not actually feed on the cattle’s blood, but they still cause problems. They annoy the cattle and ultimately impact the productivity of the herd. The female flies feed on facial secretions such as tear fluid, which causes mechanical damage to the eyes and can lead to conjunctivitis.

Dung beetles reduce the numbers of both these flies by competing with the fly larvae for food and physically damaging the eggs. One study has shown that the presence of dung beetles on a cow pat reduces the number of horn flies by 95 percent!

Reduction in Gastrointestinal Parasites

Cattle can suffer from many intestinal parasites, including flukes, pole worms, stomach worms, and intestinal worms. The eggs of many of these pass out with the feces and are contained in the dung pat. The eggs hatch into larvae, migrate into the grass, and are ingested by other cattle, so the lifecycle starts again. By removing the manure, the dung beetles interrupt this lifecycle and reduce the number of intestinal parasites.

Forage Availability

Cattle are quite fussy about where they graze. They do not like to eat grass that is close to dung pats created by their own species! So, the presence of dung pats can reduce the area of pasture available for eating by as much as 5 or 10 percent. Because dung beetles quickly remove the dung pat, the area becomes available for grazing again much sooner. In ideal conditions, dung beetles can remove a dung pat in 24 hours, with most of the nutrients being taken down into the soil. If a dung pat is left to dry out without their intervention, up to 80 percent of the manure’s nitrogen is lost through volatilization. Farmers and ranchers are increasingly recognizing the value of dung beetles and the advantages they have over pesticides.

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