The lamellar family is distinguished by some peculiarities in the structure of the mustache and club, as well as a huge number of very interesting species. There are representatives in this family who can easily be considered record holders, both in size and in mass of objects moved. Some of them are able to move loads that are 1000 times the weight of the insects themselves.
As a rule, the life activity of the vast majority of species is inextricably linked with the soil, and nutrition with coprophagy. The development of a biocenosis is associated with the disposal of excrement, as well as residues of various origins, which is very important for the environment. The dung beetle is busy ridding the upper layers of the soil of the remains of various animals, which leads to the formation of a fertile ball of soil, as a result of which it is possible to collect significant harvests. These are truly hardworking creatures, from whom one can only expect benefits for both nature and humans.
Description and features
Dung beetles are representatives of the order Coleoptera, belong to the family Lamelidae and are included in the numerous subfamily of shrews. What a dung beetle looks like depends on a number of factors, in particular the species to which it belongs and its habitat. Thus, the size of the imago can vary from 1 to 7 cm, weight - from 0.75 to 1.5 g. The color can be black, brown, blue, green, yellow.
Moreover, all adult insects have:
- oval or round body shape;
- head directed forward;
- antennae consisting of 11 segments and ending in fan-shaped plates;
- three pairs of legs with serrated tibiae along the outer edge and 2 spurs on the apex;
- abdomen, consisting of 6 sternites, on which 7 spiracles are located;
- mouthparts of the gnawing type.
Also, all beetles have strong, thick, chitinous elytra, under which are leathery wings. But not all drillers can fly; some have completely lost the ability to move through the air.
Interesting! During flight, the elytra of dung beetles practically do not open. This contradicts all the laws of aerodynamics, but does not interfere with the insects themselves. Their flight is so masterly and precise that they can easily catch a moving fly (even many birds cannot do such a trick!)
Genus classification
There are more than 600 species of dung beetles in the family Geotrupidae. It should be borne in mind that there are several subfamilies, such as:
- Subfamily Bolboceratidae, which includes both large and medium-sized beetles. Most species of this subfamily live in the Palearctic. Beetles of this genus grow to 15–23 mm in length, their palps consist of 11 segments, and their tentacles consist of 3 segments. These beetles are distinguished by black, brown or two-colored elytra. The wings are well developed, so the beetles fly from one place to another without any problems. Adult beetles most readily feed on mushrooms, and larvae feed on humus.
- The subfamily Geotrupinae are beetles that reach medium size and are distinguished by prominent upper jaws and lips. The club may be lamellar or abaxial. The forelimbs have 4 to 9 teeth located along the outer edge. Beetles of this subfamily feed on the feces of mammals. In addition, their diet includes mushrooms and forest litter.
- The subfamily Lethrinae has a convex, oval body, up to 35 mm long. They can be distinguished from representatives of other families by the presence of mandibular processes located on the upper jaw in males. The mace is surrounded and therefore cannot spread. Representatives of this subfamily do not fly and prefer to live in burrows. During breeding, males are aggressive towards each other. The male and female copulate on the surface. To provide food for their larvae, beetles collect various organic substances.
Kinds
Today, scientists classify 750 species of beetles as dung beetles, divided into two main groups: Coprophaga and Arenicolae. The main difference between representatives of both groups is that the beetles belonging to Coprophaga have covered and leathery upper lips and jaws. In Arenicolae these parts are hard and uncovered.
The most famous types include:
- Common dung beetle (Geotrupes stercorarius L.). Typical representative. Length 16-27 mm. On top, the body is black in color with a pronounced shine; sometimes blue or green tints or a border can be observed. The lower part of the body is purple or blue (specimens with a greenish-blue abdomen are much less common). There are 7 distinct grooves on the fender covers.
Adult beetles can be found everywhere from April to November.
- Forest dung beetle (Anoplotrupes stercorosus). Mass view. The adult size is 12-20 mm. The elytra are blue-black and have seven dotted grooves, the belly is blue with a metallic tint. Beneath the chitinous elytra are wings, which can be green, purple or brown. The antennae have a red-brown tint and large “pins” at the tips.
The period of activity of the beetle is summer, from mid-May to the first ten days of September. During this time, he manages to prepare holes with cameras and lay eggs in them.
- Spring dung beetle (Trypocopris vernalis). A rare species, listed in the Red Book of several regions of the Russian Federation and Belarus.
The body length of the insect is 18-20 mm, its shape is oval and convex. The surface of the elytra seems almost perfectly smooth, since there are practically no grooves on them. There are many small dots on the wide pronotum. There are individuals of dark blue, black-blue and green colors (the latter are very similar to bronzes, but differ from them in their lifestyle). Activity time is summer.
- The bull beetle (Onthophagus taurus). The length of the flattened body of this insect is 15 mm. It got its name for its paired outgrowths resembling horns. They can be located on the back, front or middle of the head and are found exclusively in males.
In exceptional cases, beetles do not grow horns, but in this case their “masculinity” is confirmed by enlarged genitals. Also among the most common and recognizable species of dung beetles are the rhinoceros beetle and the sacred scarab.
Natural enemies
Insects that feed on the droppings produce a disgusting odor that will repel almost anyone who might eat the bugs. Domestic chickens, crows, and omnivorous hedgehogs do not disdain dung beetles.
Inexperienced young foxes may try to eat a dung beetle due to lack of food. To scare away potential enemies, the beetle makes creaking sounds, rubbing its abdomen and elytra, and even pretending to be dead.
The body of a dung beetle can be parasitized by a special tiny mite, Gamasuscoleoptratorum, which bites the hard shell of the insect with its sharp jaws and sucks it up. A dung beetle can harbor several mites at the same time.
Lifestyle and habitat
As a rule, the dung beetle is an insect that does not tolerate drought and heat. Therefore, it lives mainly in regions with temperate and cold climates. However, in the large “family” of dung beetles, there are also those that have perfectly adapted to life in desert conditions (such as scarabs).
Various types of dung beetles are widespread in Europe, both Americas, and South Asia. Some of them even chose the regions of the Far North of Russia. Relatively recently, dung beetles have settled in Australia. The colonization of the continent by beetles was initially carried out artificially, but favorable conditions allowed the insects to quickly multiply and spread over large Australian territories.
At first, the beetles are active during the daytime. However, the more the ambient temperature rises, the less often they can be seen on the street during daylight. Subsequently, dung beetles are nocturnal, appearing in illuminated places only when any danger arises.
They spend almost all their time in their burrows, the depth of which can range from 15 cm to 2 meters. Beetles dig their shelters under a layer of fallen leaves or a dung heap. They crawl to the surface only for the next portion of manure. They roll the prey they find into a ball. It is with such a ball that the dung beetle is depicted in the photos and drawings of visual aids.
Insects hold the dung ball with their hind legs. At the same time, moving his front legs, he moves in the direction he needs, carrying his burden with him. Most dung beetles are loners, forming pairs only during the mating season, but there are species that prefer to live in small colonies. At the same time, males are very fond of “sorting things out.” Sometimes fights arise over females, but most often the beetles share especially tasty morsels of food.
And among dung beetles there are individuals who steal other people’s balls using “cunning.” First, they help other insects roll the burden to the right place, and then, when the owner gets carried away with digging a hole, they “take away” the ball. Such dung beetles are called raiders.
Larvae
Dung beetles are not only useful, but also very smart beetles that have developed a complex system of caring for their offspring. Most often, the dung beetle hides its larvae in soil, rotting wood or manure, thus providing not only protection from the weather, but also relative warmth. To do this, the dung beetle makes a ball out of dung, which, pushing with its hind legs, moves it to a secluded place. In the future, it will serve as the main food for the larvae, ensuring full development.
The dung beetle larva is thick and inactive. Despite the fact that it spends its entire development period in manure, during this time it never defecates. Thanks to the structure of the intestines, equipped with a special expansion, all excrement is collected in one place. It is for this reason that the shape of the larva during development resembles the letter “C”.
It is noteworthy that if the dung beetle decides to lay eggs in a dung heap, then it makes oblong lumps of manure at the rate of one lump per larva.
Nutrition
Already from the name of the insect it is clear what the dung beetle eats and what its main food is. However, as scientists have found, manure is not the only food product of these beetles. Adults, for example, can eat some mushrooms, and dung beetle larvae can also feed on insects.
In addition, dung beetles have their own taste preferences. Although they can eat the waste of many animals (mostly cattle), if given a choice, they will always prefer horse manure. By the way, it is horse and sheep excrement that insects try to store for their offspring.
Interesting! Dung beetles are very picky about food. Before they start processing the manure, they sniff at it for a long time and study it with the help of their antennae. And if during the examination the beetle is not satisfied with the smell of waste, it will not eat it.
Dung beetle behavior
This beneficial insect brings great benefits to the earth, loosening and saturating it with oxygen. In the process of processing manure, the beetle rolls it into balls and sends it to its burrows, where it decomposes into organic components, which also helps to fertilize the soil, increase yield and improve the sanitary situation.
This species of beetle prefers a temperate climate; individuals adapted to arid conditions are rarely found. The main thing for insects is a sufficient amount of food for adult beetles and larvae. The only areas unsuitable for settlement by dung beetles are the territories of the Far North.
Reproduction and lifespan
Like most insects, the development cycle of borers consists of 4 successive stages: eggs, larvae, pupae and adults. The mating season begins with the onset of summer. To procreate, insects mate for a short time.
After mating, the fertilized female lays 3-6 eggs measuring about 3 mm. For masonry, the same ball of dung beetle , carefully rolled by the parents in advance. Moreover, each egg is assigned its own dung ball and a separate “room” - a branch in the underground burrow.
After 28-30 days, the larva hatches from the egg. It has a thick, fleshy cylindrical body. The base color can be creamy white, beige or yellow. The head is brown. Like the adult insect, nature provided the larva with well-developed jaws of the gnawing type. She also has thick, short thoracic legs (the abdominal limbs are not developed). On her head there are antennae consisting of three segments. But she doesn't have eyes.
This stage of development can last up to 9 months, during which the larva of the dung beetle feeds on the manure prepared for it. After this time, the larva, which has gained strength and accumulated nutrients, pupates.
Interesting! All the time that the larva spends in its “room”, its waste products are not removed outside, but are collected in a special bag. Over time, as it fills, it forms a kind of hump on the back of the larva. The meaning of this device is to prevent the offspring of the dung beetle from being poisoned by its own waste.
The dung beetle spends about 2 weeks in the pupal stage, after which the shell bursts and an adult insect is born. The total development period of the dung beetle is 1 year, while adults live no more than 2-3 months - time sufficient to leave offspring.
Lifestyle
The dung beetle lives in the ground, in dug holes, especially in places where there is leaf litter or piles of dung. The dung beetle lives in its shelter all day and comes out only in the evening, although some species are active during the day.
It is interesting to watch how beetles roll dung balls, deftly using their front legs. They roll the balls formed in this way closer to their home.
The beetles' diet includes fungi, decomposition products of organic matter, and vertebrate excrement.
Some species of dung beetles do not feed because they survive on nutrients accumulated in the larval stage.
The family Geotupidae is distinguished by territorial behavior. Males compete with each other for the right to impregnate a female. Many experts believe that females choose their mates based on the volume of dung balls they roll.
The larger the dung sphere, the more chances males have to win the favor of females and thereby continue the race. Insects mate in summer. Dung balls serve as storage facilities for beetles to feed their offspring.
The beetles create vertical burrows ranging from 15 to 200 cm in length, in which they leave space at the bottom of the burrow for the larvae. The female lays eggs on a ball of dung, then a month later a larva emerges from the egg and lives in the hole without leaving it.
Under these conditions, it overwinters and emerges from the pupa in the spring. It takes one year to develop one generation. The average lifespan of a beetle is about 2 months.
Benefits and harms for humans
Some gardeners consider these insects to be harmful and take various measures to eliminate them from their plots. However, this opinion is fundamentally wrong, and drillers do no harm. Quite the contrary, these creatures bring great benefits to both the soil and the plants of the garden.
The main benefit is that the dung beetle is a decomposer ; it promotes the processing of complex organic compounds into simpler ones that can be absorbed by plants. That is, it is thanks to these insects that manure becomes “useful” and begins to “work” to increase productivity.
A striking example of the benefits of the beetle is the situation in Australia. The fact is that with the influx of settlers to the southern continent, the number of livestock here also increased sharply. Moreover, the breeding of the latter was facilitated by extensive pastures with green, lush grass.
However, the joy of the settlers (especially those who began to make money from the export of meat and wool) was short-lived. After just a few years, the vegetation ceased to renew itself, and many pastures turned into practically deserted areas. The change in diet from lush grass to sparse tough bushes had a negative impact on the number of livestock and on the quality of the products obtained from them.
After scientists (ecologists, biologists, entomologists and others) got involved in solving the problem, it became clear that the lack of vegetation is directly related to the excess of manure on former pastures. Having dried and compressed, animal waste simply did not allow the grass to “break through” to the light.
As a solution to the problem, these same scientists proposed using the “labor” of dung beetles. Since no suitable insects were found in Australia, they were brought here from other continents. Representatives of the lamellar shrews brought to the site quickly understood their task and in just a few years were able to correct the situation - the pastures of Australian cattle breeders were once again covered with fleshy green stems of herbaceous plants.
Considering all this, it is unlikely that any Australian gardener or gardener would call dung beetles harmful and dangerous insects. By the way, manure processing is not the only benefit brought by these Coleoptera. When equipping their shelters, they dig passages, loosening the soil, which, in turn, contributes to its saturation with oxygen.
In addition, by rolling dung balls, beetles contribute to the spread of various seeds (it is known that the droppings of large and small livestock contain undigested plant remains, including their seeds).
Role in nature
A very interesting and instructive story is connected with dung beetles. During the period of exploration of the Australian continent by European colonists, as is known, a variety of livestock, which had never lived in Australia before, were brought there. Sheep are the most widespread species here. The wool sent to England yielded fabulous profits, and therefore the flocks of sheep grew rapidly. However, farmers soon began to notice the depletion of pastures. The once thick and lush green grass stands degenerated into meager bushes of semi-dry grasses, on which the sheep did not gain the necessary weight, as before.
The experts involved in solving the problem solved the mystery: it turned out that all the local pastures had become covered with a dense layer of sheep manure over many years of grazing. There was simply no one here to process it. Among Australian insects there were no dung beetles that would consider sheep waste worthy food for themselves. As a result, plants had difficulty breaking through the dried manure shell. This problem had to be solved somehow.
For this purpose, entomological specialists were involved. They quickly found a way out of an unpleasant situation. Expeditions were sent to Europe, whose participants were tasked with finding dung beetles, for which sheep manure was their favorite food.
It should be noted that by that time the Australians had already been repeatedly frightened by ill-conceived imports (introductions) of foreign plants and animals (it is enough to recall the catastrophic reproduction here of American species of prickly pear cacti, and later of rabbits). And dung beetles, as we already know, are often accompanied by completely foreign creatures, for example, parasitic gamas mites. It was these, in particular, that Australian entomologists were afraid of accidentally introducing. It is unknown how these parasites would behave if they moved to local Australian dung beetles.
To ensure that new species of dung beetles do not introduce any harmful organisms that accompany them to the continent, this time all precautions were taken. A special intermediate laboratory was organized in South Africa, where beetles caught in Europe were comprehensively examined and studied over several generations.
About 50 species of dung beetles were subjected to such a comprehensive check.
Finally, the species that turned out to be the most promising for solving the problem were transported to Australia and released into the wild. As entomologists predicted, finding themselves among the “ocean” of their favorite food, the “settlers” began to multiply rapidly, literally following on the heels of the sheep. As a result, as strange as it may sound, dung beetles helped solve a major national economic problem.
Interesting Facts
The dung beetle is not only an extremely useful, but also a very interesting insect. Here are just a few unusual and surprising facts about him:
- Having formed its ball, the beetle rolls it in the desired direction, guided by the stars!
- Long before the creation of special services, dung beetles helped predict the weather for the next day. Attentive people have noticed that if insects are more active during daylight hours, then the next day will definitely be warm, sunny and windless.
- According to scientists, up to 16 thousand dung beetles can live in one pile of elephant dung weighing only 1.5 kilograms.
- The beetle can sense potential danger. At the same time, it begins to produce a sound similar to a squeak.
- Dung beetles are able to extract moisture practically from the air (by the way, this is how many of them survive in the African desert). To do this, they turn towards the wind and spread their wings. After some time, particles of moisture begin to settle on the convex areas of the insect’s head. Gradually accumulating, the particles collect into a drop, which in turn flows directly into the dung beetle’s mouth.
- Drillers hold the record for strength among insects. After all, they are able not only to roll a ball that is much larger than themselves, but also to pull a load that weighs 90 times their own weight. In terms of human strength, dung beetles simultaneously move a mass equivalent to 60-80 tons (this is the approximate weight of 6 double-decker buses at once).
And dung beetles are also quite smart and inventive. Proof of this can be the experiment of the famous entomologist Jean-Henri Fabre with scarabs. While observing the beetle, the scientist “nailed” the dung ball to the ground using a pancake needle. After being unable to move the burden from its place, the insect dug under it.
Having discovered the reason why the ball could not be moved, the dung beetle tried to remove it from the needle. He used his own back as leverage. He needed just a little to carry out the idea. Subsequently, when Fabre placed a pebble next to a lump of dung, the beetle climbed onto it and nevertheless freed its “treasure”.
How to fix
The larvae of some subspecies are pests. Agricultural crops are destroyed. To combat dung beetles, water the soil with onion broth in the spring.
Another effective method is the construction of a bait. To do this, place a barrel coated with grease in the garden, and place a light source at the bottom. Not only dung beetles, but also other pests will fly to such a structure.
There are no special chemicals to kill shrews. This also applies to preventive methods. In most cases, the beetle is beneficial and does not need to be destroyed.
