Dung beetle

The dung beetle, belonging to the Lamellar family and subfamily of the scarab, also called the dung beetle, is an insect that forms dung into a ball using its shovel head and paddle-like antennae. In some species, the ball can be the size of an apple. In early summer, the dung beetle burrows itself into a ball and feeds on it. Later in the season, the female lays her eggs in dung balls, which the larvae then feed on.

Origin of the species and description

Photo: Dung beetle

Photo: Dung beetle

Dung beetles evolved at least 65 million years ago as dinosaurs declined and mammals (and their droppings) got bigger. There are about 6,000 species worldwide, concentrated in the tropics, where they feed mainly on the dung of terrestrial vertebrates.

The sacred scarab of ancient Egypt (Scarabaeus sacer), found in many paintings and decorations, is a dung beetle. In Egyptian cosmogony, there is a scarab beetle rolling a ball of dung, and a ball representing the Earth and the Sun. The six branches, each with five segments (30 in total), represent the 30 days of each month (in fact, this species only has four leg segments, but closely related species have five segments).

Video: Beetle -dungeon

An interesting member of this subfamily is Aulacopris maximus, one of the largest dung beetle species found in Australia, measuring up to 28 mm in length.

Fun fact: Indian scarabs Heliocopris and some Catharsius species make large dung balls and cover them with a layer of clay, which becomes dry; they were once thought to be old stone cannonballs.

Members of other scarab subfamilies (Aphodiinae and Geotrupinae) are also called dung beetles. However, instead of forming balls, they dig a chamber under a pile of dung, which is used during feeding or to store eggs. The droppings of the Aphodian beetle are small (4 to 6 mm) and usually black with yellow spots.

The Geotrupes dung beetle is approximately 14 to 20 mm long and is brown or black in color. Geotrupes stercorarius, known as the common dung beetle, is a common European dung beetle.

Appearance and Features

Photo: What a dung beetle looks like

Photo: What a dung beetle looks like

Dung beetles are usually round with short wings (elytra) that expose the end of the abdomen. They vary in size from 5 to 30 mm and are usually dark in color, although some have a metallic sheen. In many species, males have a long, curved horn on their heads. Dung beetles can eat more than their weight in 24 hours and are considered beneficial to humans as they speed up the process of converting manure into substances used by other organisms.

Dung beetles have impressive “weapons”, large horn-like structures on head or chest, which males use to fight. They have spurs on their hind legs to help them roll dung balls, and their strong forelegs are good for both fighting and digging.

Most dung beetles are strong fliers, with long flight wings folded under hardened outer wings (elytra) and can travel several kilometers in search of ideal dung. With the help of special antennas, they can smell manure from the air.

Pushing even a small ball of fresh dung can weigh up to 50 times the weight of a particular dung beetle. Dung beetles need exceptional strength, not only to push dung balls, but also to fend off male competitors.

Fun fact: The individual strength record is going to the dung beetle Onthphagus taurus, which withstands a load equivalent to 1141 times its own body weight. How does this relate to human feats of strength? It would be like a man pulling 80 tons.

Where does the dung beetle live?

Photo: Dung beetle in Russia

Photo: Dung beetle in Russia

The widely distributed family of dung beetles (Geotrupidae) has over 250 different species that are distributed throughout the globe. About 59 species live in Europe. Dung beetles mainly live in forests, fields and meadows. They avoid climates that are too dry or too wet, so they can be found in subtropical and temperate climates.

Dung beetles are found on every continent except Antarctica.

Also lives in the following places:

  • farmland;
  • forests;
  • grasslands;
  • prairies;
  • in desert habitats.

They are most commonly found in deep caves, feeding on vast amounts of bat dung and in turn preying on other giant invertebrates that roam the dark passages and walls.

Most dung beetles use the dung of herbivores, which are poor digest food. Their dung contains semi-digested grass and a smelly liquid. It is this liquid that adult beetles feed on. Some of them have special mouthpieces designed to suck out this nutritious soup, which is full of microorganisms that bugs can digest.

Some species feed on carnivore dung while others skip it and instead eat mushrooms, carrion, and decaying leaves and fruits. The shelf life of manure is very important for dung beetles. If the manure has lain long enough to dry out, the beetles cannot suck out the food they need. One study in South Africa showed that dung beetles lay more eggs during the rainy season when they contain more moisture.

What does the dung beetle eat?

Photo: Insect dung beetle

Photo: Insect dung beetle

Dung beetles — coprophagous insects, that is, they eat the excrement of other organisms. While not all dung beetles feed exclusively on dung, they all do at some point in their lives.

Most prefer to feed on grass dung, which is largely undigested plant matter, rather than carnivore waste, which has very little nutritional value for insects.

Recent research at the University of Nebraska shows that dung beetles are most attracted to omnivorous feces, as they provide both nutritional value and just the right amount of scent to make it easy to find. They are fussy eaters, picking up large chunks of manure and dividing it into tiny particles, ranging in size from 2-70 microns (1 micron = 1/1000 of a millimeter).

Fun fact: All organisms need in nitrogen to build proteins such as muscles. Dung beetles get them from dung. By eating it, dung beetles can select cells from the intestinal wall of the herbivore that produced it. It is a protein-rich source of nitrogen.

Recent research suggests that obesity and diabetes in humans may be related to our separate gut microbiomes. Dung beetles can use their gut microbiome to help them digest the complex components of dung.

Personality and Lifestyle Traits

Photo: Ball dung beetle

Photo: Dung beetle ball

Scientists group dung beetles according to how they make a living:

  • rollers form a ball of manure, roll it and bury it. The balls they make are either used by the female to lay eggs (called a blur ball) or as food for the adults;
  • Tunnelers land on a patch of dung and simply dig into the patch, burying some of the dung;
  • the inhabitants are content to stay on top of the dung to lay their eggs and raise their young.

Battles between the rollers, which take place on the surface and often involve more than just two beetles, are chaotic skirmishes with unpredictable consequences . The biggest one doesn't always win. Therefore, investing energy in growing weapons for the body, such as horns, would not be profitable for rollers.

Interesting fact: 90% of dung beetles dig tunnels right under the manure and make an underground nest from brood balls in which they lay their eggs. You'll never see them unless you're prepared to dig through the manure.

On the other hand, rollers transport their prize on the surface of the soil. They use celestial signals such as the sun or moon to stay away from competitors who might steal their balloon. On a hot day in the Kalahari, the soil surface can reach 60°C, which is death for any animal that cannot control its body temperature.

Dung beetles are small, as is their thermal inertia. Therefore, they heat up very quickly. To avoid overheating, as they roll their balls under the scorching midday sun, they climb to the top of the ball to cool off for a moment before striding hotly across the sand in search of shade. This allows them to roll further before returning to the ball.

Now you know how the dung beetle rolls the ball. Let's see how this insect reproduces.

Social structure and reproduction

Photo: Scarab Dung Beetle

Photo: Scarab beetle

Most dung beetle species breed during the warmer months of spring, summer, and autumn. When dung beetles carry or roll away dung, they do so primarily to feed their young. Dung beetle nests are stocked with food, and the female usually lays each individual egg in her tiny dung sausage. When the larvae emerge, they are well supplied with food, allowing them to complete their development in a safe habitat.

The larvae will go through three skin changes to reach the pupal stage. Male larvae develop into major or minor males depending on how much dung is available to them during their larval phases.

Some dung beetle larvae are able to survive adverse conditions such as drought by stopping development and remaining inactive within a few months. The pupae develop into adult dung beetles that break out of the dung ball and dig them to the surface. The newly formed adults will fly to the new dung pad and the whole process starts all over again.

Dung beetles — one of the few groups of insects that show parental care for their young. In most cases, the responsibility of raising a child is left to the mother, who builds the nest and provides food for her children. But in some species, both parents share the responsibility for caring for the child to some extent. In the dung beetles Copris and Ontophagus, the male and female work together to dig their nests. Certain dung beetles even mate once for a lifetime.

Natural enemies of dung beetles

Photo: What a dung beetle looks like

Photo: What it looks like dung beetle

Several reviews of the behavior and ecology of the dung beetle (Coleoptera: Scarabaeidae), as well as numerous research reports, either implicitly or explicitly indicate that predation on dung beetles is rare or non-existent and therefore of minimal or no significance to the biology of the group .

This review presents 610 records of dung beetle predation from 409 species of birds, mammals, reptiles and amphibians from around the world. The involvement of invertebrates as predators of dung beetles has also been documented. It is concluded that these data establish predation as a potentially important factor in the evolution and modern behavior and ecology of dung beetles. The data presented also represent a significant underestimation of predation in the group.

Dung beetles also fight their brethren for dung balls, which they make to feed on and/or serve as sex objects. Elevated chest temperature plays a crucial role in these competitions. The more the beetle shivers to keep warm, the higher the temperature of the leg muscles adjacent to the flight muscles in the thorax, and the faster its paws can move, collect droppings into balls and roll it away.

Endothermia, therefore, helps in the fight for food and reduces the duration of contact with predators. In addition, hot beetles have an edge in competition for dung balls made by other beetles; in battles for dung balls, hot beetles almost always win, often despite a big disadvantage in size.

Population and Species Status

Photo: Dung beetle rolls a ball

Photo: Dung beetle rolls a ball

The population of dung beetles has about 6000 species. The ecosystem contains many coexisting dung beetle species so that competition for dung can be high, and dung beetles exhibit a variety of behaviors to be able to secure the dung for feeding and breeding. In the near future, the population of dung beetles is not in danger of extinction.

Dung beetles are powerful processors. By burying animal manure, the beetles loosen and nourish the soil and help control fly populations. The average domestic cow sheds 10 to 12 pieces of manure per day, and each piece can produce up to 3,000 flies within two weeks. In some areas of Texas, dung beetles bury about 80% of cattle dung. If they didn't, the manure would harden, the plants would die, and the pasture would become a barren, stinking landscape filled with flies.

In Australia, native dung beetles couldn't keep up with the tons of manure deposited by livestock on pastures, which led to a huge increase in the fly population. African dung beetles that thrive in open fields were brought to Australia to help with growing manure piles, and today the rangelands are doing well and fly populations are under control.

The dung beetle does exactly what it does what his name says about him: he uses his own dung or that of other animals in some unique ways. These interesting beetles fly in search of the dung deposits of herbivores such as cows and elephants. The ancient Egyptians held in high regard the dung beetle, also known as the scarab (from their taxonomic surname Scarabaeidae). They believed that the dung beetle made the Earth rotate.

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