Matt pill roll

from Wikipedia, the free encyclopedia
Matt pill roll
Dull pill roll when moving a dung ball

Dull pill roll when moving a dung ball

Systematics
Order : Beetle (Coleoptera)
Subordination : Polyphaga
Family : Scarab beetle (Scarabaeidae)
Subfamily : Scarabaeinae
Genre : Sisyphus
Type : Matt pill roll
Scientific name
Sisyphus schaefferi
( Linnaeus , 1758)

The mat pill tome or mat Pillendreher ( Sisyphus schaefferi ), also Leggy Pillendreher is a beetle from the family of scarab beetles . Despite a similar way of life, the mat pill roll does not belong to the dung beetles ; the genera Sisyphus , Scarabaeus and Gymnopleurus form the tribe Scarabaeini.

The species, which occurs mainly in southern Europe, but also, for example, at the Kaiserstuhl, makes balls from excrement or manure, transports them to suitable places and bury them there as a source of food for their offspring.

The generic name Sisyphus refers to the hero of Greek mythology , as one can often observe the beetle trying to transport its balls over an obstacle in seemingly hopeless situations. The species name schaefferi honors the theologian and entomologist Jacob Christian Schäffer .

Sisyphus schaefferi is the only European representative of the genus Sisyphus . In Europe it occurs in the west in the subspecies Sisyphus schaefferi schaefferi , in the east in the subspecies Sisyphus schaefferi boschniaki .

Fig. 1: Head and partially forelegs
Fig. 2: H: splint and tarsus of the hind leg from above
M: splint and tarsus of the middle leg from the side
Fig. 3: Bottom
Fig. 4: Video of the production and transport of brood pills

Characteristics of the beetle

The beetle becomes seven to thirteen millimeters long. The black to black-brown matt colored body is strongly arched and pointed backwards. It is hairy yellow to black-brown. The hair is curved and sloping backwards.

The head (Fig. 1) is clearly dotted . The protruding head shield is cut off concavely at the front and raised to a blunt point on the sides of the cutout. It hides the mouthparts . The upper lip is membranous and almost square. The upper jaws are fringed on the inner edge. The jaw probes are four-link with a long end link. The lip probes are tripartite with a very small, egg-shaped end member. The hemispherical compound eyes are also largely hidden by expanding the head skeleton. Most of it lies below this extension, the view upwards is only possible through a narrow slit (Fig. 1 and 3). The last three links of the eight-link antennae are widened forward and form an almost egg-shaped club.

The large pronotum is strongly arched. It is densely dotted like a navel and only briefly hairy.

The wing covers remain closed during flight. They narrow strongly towards the rear and are almost triangular, curved convexly on the outer edge . They wear eight shallow chain strips. The label is not visible.

The legs are adapted to the production, transport and burying of the fecal balls. The short front legs are designed as grave legs with three external teeth on the rails (Fig. 1). The mid-hips are set wide apart and almost parallel to each other (Fig. 3). The middle rails have two strong spikes at the end (Fig. 2, M). The hind legs (Fig. 2, H) are articulated far back. The hind legs are thickened club-shaped towards the tip. The back rails are long and curved so that they can partially encircle the dung balls. They are widened and serrated to the rear. They only have one end pin. The tarsi are all five-part.

biology

There are relatively old observations on the biology of the Matten Pill Rollers, in particular from the French naturalist Jean-Henri Fabre . He describes the beetle as the smallest and most eager of all pill-makers, which no other can match in its lively busyness, its awkward somersaults and its unexpected crashes on the impossible routes on which it persists in its stubbornness. However, some of these descriptions have not been confirmed or even refuted by more recent work. This is mainly due to the fact that males and females do not differ externally and the larger animal of a couple used to be mistaken for the female. Joachim Prasse has dealt with the species in great detail. The following statements refer mainly to his four publications, in which he compares the Matten Pill Roll Sisyphus schaefferi with the Silky Pill Roll Gymnopleurus geoffroyi .

Life cycle

The development cycle is one year, the wintering takes place as a fully developed insect. The beetle can be found on warm and dry slopes that are used as pastures. As warmth-loving animals, the beetles that hatched in the previous year (old beetles) in Central Europe only end their winter dormancy when temperatures reach high values ​​in May after the warm previous months. On cooler days, the animals only leave the protective area of ​​the ground in the warm midday hours; in midsummer, on the other hand, they are already active in the morning hours and even at dusk. Activity is most noticeably influenced by temperature. In warm and dry weather between 20 ° C and 26 ° C, the beetles are nimble and happy to fly. Even the shadow of a cloud slows down activities considerably. When the weather is unfavorable, the acquisition of food and activities related to reproduction are almost stopped. The beetles stop their activities when it rains lightly, and dig in when it rains heavily. Weak winds have little influence on activities, but stronger winds have a very inhibiting effect.

The eggs are laid from the beginning of June to mid-July. For the development from egg-laying to hatching from the pupa, the beetle needs 63 to 69 days at a temperature of 18 ° C to 20 ° C, and 51 to 55 days at a temperature of 24 ° C to 25 ° C. The young beetles appear from the beginning of August.

According to Prasse, the average lifespan of the adults is 360 days. Few of the old animals did not die until September, the oldest was 404 days old. The females die eight to ten days earlier than the males. The aging of the beetles becomes noticeable through the decrease in irritability and readiness to fly. Food intake is decreasing and attempts to escape are increasingly neglected. Finally, body cleansing is neglected. Often, mites settle in large colonies, mainly on the ventral side of the chest section. Largely weakened animals can no longer find the strength to dig themselves into the ground in the evening and die overnight. It is not uncommon for individual leg links to be lost. Usually, however, the animals perish buried in the ground.

Ingestion

After hatching, both sexes require maturation in order to reach sexual maturity . This extends in the year of the beetle's birth from when it appears until it is buried in the winter and continues in the spring of the following year until the beetle reaches sexual maturity. During this time, the beetles eat directly on the excrement found or they make so-called food pills from manure, which they bury and consume underground. Only at sexual maturity can you see two beetles making dung balls together. These can be made for common consumption (food pills) or they are intended as food for the offspring and are then called brood pills. In both cases, a male and a female work together. With the restriction that less high quality material is used for food pills, food pills and brood pills do not differ in size and composition. The size of the pill depends only on the size of the animal that makes it. Jointly made pills are no bigger than those made by just one animal.

According to Prasse's research, in contrast to the information provided by other authors, not only breeding pills are produced during the reproductive period, but also food pills made exclusively for consumption by the manufacturer (s). During the reproductive period, food pills as well as brood pills can be made by single males, single females or by a couple together.

Experiments show that with beetles that are kept separate according to sex, the urge to produce food pills decreases significantly with the onset of sexual maturity, and the production of pills is sometimes completely stopped. If partners of the opposite sex are added, the animals start producing food pills again relatively quickly, and do so together. Males and females recognize themselves as such by their smell. Three possible scenarios are observed. Either males and females recognize each other at the feeding station and then build a feed pill together. Or the female approaches a male pill owner. Without any fuss, they roll the food pill on together. Or a male approaches a pill with a female owner. Then this only allows after a critical examination of the male that the pill is rolled further together. These different scenarios can be explained by the fact that the male recognizes the female as such from a great distance, while the female only recognizes the male from close proximity. This is also supported by further observations.

The beetle prefers sheep droppings for ingestion, but is also often found on other types of droppings, not only on the droppings of herbivores, but also on the droppings of omnivores , for example humans. Feeding experiments with 15 types of faeces showed that the excrement of sheep, red deer, cattle, zebu and camel was accepted by all test animals without hesitation (category A). The faeces of goats, horses, humans and pigs were not accepted immediately by all animals, but only hesitantly by some (category B). The feces of elephants, rabbits, brown bears and dogs were only accepted after periods of starvation (category C), the feces of lions and chickens were spurned even after periods of starvation (category D). The quality of the food is also assessed according to whether it is good enough for the production of food pills or for the production of brood pills. Only the category A droppings, which were accepted without hesitation, were also used for the manufacture of breeding pills. Food pills, on the other hand, were made from all types of droppings in the first and second categories. However, no food pills were made from the feces of elephants, rabbits, brown bears and dogs that were eaten in an emergency.

Further experiments showed that carrion was also used as a source of food after five days of starvation if no alternative food was available. Attempts have also been made, in some cases, to form balls from the carcass and bury them. Prasse suspects that necrophagy does not occur under natural conditions . Attempts to determine whether rotting mushrooms are also a possible source of food did not lead to a positive result.

A more recent study of the food spectrum shows that it is much larger. Regular sampling in northern Italy revealed pills made from cattle manure and the droppings of brown hare , deer , wild boar , badger and feeding activity on the decomposing nettle- stemmed witch's tube . The frequency of the beetle in the investigated area has increased noticeably over the past few years - possibly as a result of climate change.

In this study, traps were set with various thick boletus , champion species ( palliota ), chicken and pork. Measured by the frequency of the beetles, the meat traps were almost never accepted and the meat never attacked. The same goes for the traps equipped with champions. The traps with thick boletus, on the other hand, were regularly accepted. The construction and transport of pills made from the mushrooms and fights between the beetles were also regularly observed. It could not be decided whether it was food and / or brood pills.

When looking for food, the beetles fly or crawl around with their antennae stretched out and the antennae lamellae spread. If the dung is perceived olfactory , the beetle lands immediately. Running beetles stop now and then, keep their abdomen lowered and their heads raised, and turn them back and forth with their antennae outstretched. If they do not perceive any fragrances, they continue walking in the same direction. Otherwise they turn abruptly in the direction of the fragrance source and begin to run towards it at increasing speed. Shortly before reaching the source of the fragrance, perception begins through the maxillary buttons, which are moved lively. Once at the food source, it is checked with lip and jaw sensors before the eating process begins. The beetles also feed on dung piles above ground, but they prefer to feed underground on dung pills that they have made for this purpose and buried in the ground. During the reproductive phase, food above ground predominates in the dung heap, while food pills are almost exclusively consumed underground during the maturation phase.

The duration of food intake varies greatly. If there is a sufficient supply of food, the above-ground food intake can be limited to briefly absorbing moisture, on the other hand hungry animals eat for several minutes to half an hour before making a food pill. Food intake is only interrupted to clean the mouthparts . Considerable amounts are consumed in the process. For example, a female used a total of about eight hours to eat within two days and consumed 0.45 g of sheep droppings, which corresponds to 265% of body weight. When eating underground, the beetle begins to eat immediately after digging in the food pill on the underside of the pill, in order to subsequently consume it completely, progressively upwards, except for coarse components.

After just a short period of eating, the beetle excretes a black-brown, shiny strand that is getting longer and longer. This consists of short, closely spaced, cylindrical parts of two to three millimeters in length, which are created by the dropping of the faeces in short intervals and held together by a common membrane. The excrement piles up behind the animal. A total length of the droppings of 63 cm was measured in one heap. Excretions from the Malpighian vessels are excreted along with the feces , which often cling to the beetle as a white coating on the side of the abdomen.

Brood care refers to the cooperation of the sexes to protect the eggs, larvae and pupae and to provide larval food. There is no guarding and caring for, for example, the moonhorn beetle, or even feeding the young, as is the case with the gravedigger . Both males and females can judge whether the manure found is suitable for making breeding pills.

Copulation

The copulation takes place both above ground on or under the dung pile and underground on the food pill or the brood pill. A minimum temperature of 18 ° C is required. After reaching sexual maturity in late May to early July, copulation is most frequently observed during the midday heat.

The male climbs from behind or from the side of the female, stroking her front legs over her pronotum and the wing covers. If the female is not willing to mate, the male strips it off with its hind legs and the middle pair of legs; the male tries to change the mind of the female by further stroking. If the female allows it, the male clings to the base of the wing cover with the front tarsi and slides back over the end of the body and rests on the third pair of legs. The penis is stretched out and a semen packet is inserted into the female. Copulation lasts fifteen to fifty minutes. The size of the beetles does not matter, animals of the same size mate, or the male or female is larger than the partner. During the breeding period, the females are mated several times, presumably by different males outdoors.

Making the pills

Fig. 5: Sheep droppings
Fig. 6: Cattle droppings
Fig. 7: Dispute over food pills

Sheep excrement consists of excrement beans more or less stuck together (Fig. 5). The beetle chooses a bean as the starting point for its ball. If this is too big, parts of the bean with the head shield are peeled off. If it is too small, parts of other beans are cut off with the front rails and pressed against the selected bean. The beetle does not leave its ball, but pushes it towards other manure beans if there is no manure within range of the front legs.

With cow dung (Fig. 6), the female usually begins to build a ball by first pressing the front legs into suitable manure and then pulling it against the body. In this way the manure is compressed and kneaded. The legs work alternately and repeatedly until a portion of processed dung is in front of the chest and a hole a few millimeters in diameter opens in front of it. The female now begins to work, slowly turning around the compressed manure by taking steps to the side. The male now works next to the female and turns in the opposite direction. This creates a ring-shaped ditch that encloses a compressed, arched manure mass. Now the two animals work their way diagonally downwards under this mass, thereby deepening the trench and the enclosed piece increasingly takes on a spherical shape. The beetles interrupt their digging work at irregular intervals and knead and press the resulting ball, peel off further dung disks from the outer edge of the ring ditch and press them against the dung ball. Finally, a beetle squeezes under the ball, separates it from the manure underneath and lifts it up a little. The underside of the sphere is now correspondingly smoothed and rounded from below. Then the top is also smoothed and rounded again and the finished ball pried out of the hole and rolled away.

For dung piles that have already become encrusted through drying, the pill can also be made from the side or even from below.

Transportation of the pills

There are two ways to get a pill around. Either the beetle stands upright with its hind legs on the pill, stabilizes it with the middle pair of legs, pulls it towards itself with the tarsi of the front pair of legs, which are clenched on top of the pill, and moves it backwards, walking. Or the beetle holds the dung ball at the top with its hind legs, the front legs reach deep under the dung ball and the legs of the middle pair of legs are stretched out to the side, which prevents the ball from rolling away to the side. The beetle braces itself with its head shield against the ground, lifts the ball slightly with its front legs and pulls the underside of the ball towards itself, while it pushes the upper side of the ball away from itself or continues to rotate it with its hind legs. With the participation of the middle pair of legs, the beetle does not run forwards over the ball, but rather, lying on its back, lets the ball run over it from front to back using the same sequence of movements and pushes it forward.

In contrast to Gymnopleurus geoffroyi , males and females use both techniques. If a pill is transported by only one beetle, it also uses both techniques. He always tries to take the pill first. If this is unsuccessful because of the nature of the subsurface, he pushes the pill. If a pill is transported by two beetles, one pulls, the second positions itself across from it and pushes. Mostly (80%), but not exclusively as with the Silky Pill Roll, the male pulls and the female pushes. The change between the two locomotion techniques can also be seen in the video (Fig. 4).

Occasionally, transport damage is repaired en route. The pill is neither actively provided with an earth's mantle to prevent dehydration, nor is it additionally compressed. In the field it was measured that the pills were rolled two to nine meters. In the terrarium , a couple rolled around for seven hours at an average speed of 1 cm per second, which after subtracting the rest breaks corresponds to a distance of 145 meters. The weight of the pill was 2.1 grams, the weight of the animals was 0.20 grams and 0.18 grams, respectively.

In the case of obstacles, one recognizes an effective cooperation between the couples and a strong tendency to maintain the direction of transport. In one case, a couple got into the corner of a seven centimeter high enamel basin while rolling the dung ball. The pulling beetle succeeded in clawing its hind legs on the upper edge of the pelvis, where the enamel had come off, and pulled up the pill and partner. When attempting to climb a pane of glass, a couple gave up after thirty minutes and buried the pill near the pane.

Burying the pills

Both sexes are capable of digging pills. The food pills are buried less deep than the brood pills, namely only four to eleven centimeters deep. The food pills are then eaten without creating a chamber around them. The brood pills, on the other hand, are stored in brood chambers, they are on average thirteen centimeters deep. The size of the chamber, 19 to 26 millimeters high and 18 to 28 millimeters wide and long, allows the beetle to move freely around the brood pill.

According to Fabre , the beetle is specifically looking for a place that is convenient to bury the pill. Prasse puts this statement into perspective. He also reports that the animal that pulls the ball sometimes moves up to 25 cm away from the ball and several times, changing direction, explores the area with its head stretched up and the feeler blades spread, but the ball is usually approached independently of these inquiries buried in a spontaneously chosen spot. If a couple works together, the division of labor is as follows:

The partner who drew the ball (usually the male) digs head first under the ball. Then it pushes the earth under the ball upwards laterally with its head and pronotum, repeating this process several times with a different starting position. This creates an earth wall around the sphere and the sphere sinks downwards. If the ball gets stuck in the resulting shaft, it is grasped with the front pairs of legs and pulled downwards. If this is unsuccessful, the beetle grabs the ball with all three pairs of legs and turns it into the shaft. The other beetle sits on top of the ball the whole time and can be buried with it. On average, it takes ten to fifteen minutes to bury, no more than 25 minutes. Cases have also been observed where the digging was aborted unsuccessfully and a new digging attempt was started a short distance away from the unsuccessful attempt.

After the brood pill has sunk into the ground, the beetle located under the ball begins to drive the shaft vertically or slightly obliquely downwards, with a diameter that is larger than the diameter of the ball. The resulting soil is pushed out past the ball. The beetle on the ball then pushes this material upwards. This closes the shaft above the sphere and the ring-shaped earth wall is piled up into a small hill. The shaft above the sphere is filled from top to bottom with further earth masses. As a rule, the work on extending the shaft ends when it turns into an approximately horizontal two to three centimeter long corridor. This passage ends blind and contains the brood sphere. Now one beetle begins to dig up the earth around the dung ball that has sunk down, the other pushes the accumulating material up into the shaft. This creates a cave with smooth walls and a level floor, the so-called brood chamber, in the middle of which the brood pill is located.

The creation of the brood chamber is completed in about four to eight hours. If the female works alone, the working hours are extended by about a third to a quarter. After completion of the breeding cave and possibly another copulation, the male will probably leave the female of its own accord and digs to the surface of the earth.

Brood pear and egg laying

The female now transforms the brood pill into the brood pear. This takes place in two steps, the so-called re-baking and the actual production of the breeding pear. The female climbs the dung ball and works her way down into the ball with the help of her head and forelegs. It takes manure from the center of the ball, compresses it on the chest and begins to form a new ball from it. The more the new ball grows, the more the work disintegrates the old pill. Your individual parts are grasped with the front legs and added to the new ball. This process, known as baking, takes forty to fifty minutes. The product is much denser, has a rubbery consistency and has a long shelf life. It is assumed that any contaminants that have been brought in, such as the stages of flies or worms, are also destroyed.

The female now climbs on the baked ball, opens it from above and takes a portion of feces from the middle, which it deposits next to the opening created by it. The female repeats this process many times, moving in a circle around the opening in steps of two to three millimeters. As a result, the deposited manure forms a ring wall around the opening and a chamber is created in the center of the ball. The beetle now bends over the ring wall and smooths and solidifies the walls by tapping and brushing with its front legs. Presumably, the walls of the egg chamber are soaked with vomited secretion. This preparation of the egg chamber takes about one and a half to two hours.

Now the female crosses the chamber opening with her front legs and hooks herself into the ring wall with the other two pairs of legs. It then lowers the abdomen into the egg chamber so that only the head and prothorax protrude from the chamber when viewed from the side. The female remains in this position for five to thirty minutes, with a single egg leaving the body with the broad pole first. The egg usually comes to lie horizontally in the egg chamber. Then the female rises again over the ring wall and pushes it inwards, circling the pill again. After that the opening is almost closed. As the ring wall and the underlying parts are further removed and the material accumulated over the center of the opening, the pill takes on a pear-shaped shape. This brood pear is now evenly coated with soil, which the female takes from the bottom of the brood chamber. The time required for this was measured in two cases. It was two hours and three hours. The female then leaves the brood chamber for good.

The breeding pears are on average 15.4 millimeters long, 13.6 millimeters wide and 1.87 grams in weight (average of 80 objects). Fabre received 54 breeding pears from 6 pairs, so on average each female successfully produced nine breeding pears. In the Prasse cattery, a female made seven to thirteen breeding pears during the breeding season, usually ten to twelve. Probably the number is a bit higher in the wild.

Embryonic development

The freshly laid eggs are elongated oval, the point differs only slightly from the blunt end. The egg is yellowish and shiny, soft, smooth and moist. In the following days the eggs lose their shine and finally become matt. The elasticity of the egg and the egg membrane increase initially and reach their maximum after about four days. The egg then behaves like a rubber ball. Then the elasticity decreases again and sinks to the original value after six to seven days. The egg sticks to the bottom of the egg chamber with the entire side that is lying on it. The egg size fluctuates considerably, with ten freshly laid eggs the length was between 2.9 and 4.7 millimeters, the width between 1.8 and 3.0 millimeters. The egg weighs an average of 19 milligrams. The eggs are therefore unusually large and rich in yolks. Towards the end of the laying period, the eggs are slightly smaller.

During embryonic development, the egg increases in length by about 0.6 millimeters and in width by 0.9 millimeters. The future mandibles can be recognized by three-day-old eggs as two closely spaced dark spots at the tip of the egg. From the 5th day onwards you can see a stripe that reflects the future segmentation of the larva. One to two days before hatching you can see the position of the larva, the head is at the narrow end of the egg, the abdomen is wrapped up to the chest and fills the thick end of the egg. In the Prasse cattery, the eggs took eight to ten days at a temperature of 18 ° C to 20 ° C, and six to seven days for the larva to hatch at a temperature of 24 ° C to 25 ° C.

Larval stages

The species forms three larval stages. The first stage is on average 6.1 millimeters long and 2.6 millimeters wide with a head capsule width of 1.83 millimeters. The second stage is on average 11.5 millimeters long with a width of 5.2 millimeters and a head capsule width of 2.13 millimeters. In the third stage, the corresponding values ​​are 15.7 millimeters for the length of the larva, 7.3 millimeters for its width and 2.39 millimeters for the width of the head capsule.

The young larvae do not have an organ to burst the egg shell; they presumably insert their mandibles. After hatching, the larva remains calm for 24 to 48 hours, digesting the remaining yolk trapped in the intestine. Then she begins to eat. With the exception of brief interruptions during moulting, this takes place continuously. The first larva will most likely also eat the remains of the egg, but mainly it enlarges the egg chamber by consuming the manure on its walls and giving the egg chamber a spherical shape. The hump-like bulge of the larva in the second to fifth abdominal segment only develops after a few days and is caused by the loops of the middle and rectum in this area. While the egg chamber walls are initially eaten on all sides, after entering the second stage, the egg chamber is widened from the center mainly downwards. Tests on the Silky Pill Twist show that at least its larva is guided by gravity. In this direction most of the food supply is available without running the risk of breaking through the walls of the breeding pear.

Changes in the position of the larva are made by pressing two of each of the three body areas, head with legs, hump and abdominal plate, against the wall, and the third changing its position. This is only possible if the wall is everywhere the same distance from the center, i.e. the chamber has a spherical shape, and if the spherical diameter does not grow faster than the larva. This is achieved by the fact that the larva distributes its excrement, pulpy balls, on the walls again in such a way that the spherical shape is retained. As a result, it cannot be avoided that the larva also ingests its own excrement together with the material of the breeding pear. However, this is nothing special in animals with plant food, as it enables optimal digestion of the food. The free mobility of the larva enables it to close cracks and holes in the breeding pear again. Cracks are first moistened with vomited secretion, then the larva turns and excretes on the damaged part of the wall. Then the manure is spread so that the chamber is closed again.

The moults take place in that after violent bending and stretching movements, the head capsule first pops open and when the new head capsule emerges, the old larval skin tears open in the direction of the back. Before moulting, food intake is stopped, after moulting there is a rest phase to harden the chitin . As with the first larval stage, food intake takes place almost without interruption in between.

During the third stage, the larva attaches fat under the skin. The color changes from gray-white to yellow-white and the body swells a lot. About four days before the larval development ends, the larva stops eating and completely empties the intestines. The contents of the intestine are spread on the wall of the dwelling cavity. The larva decays into the almost immobile state that precedes pupation. The total time of the stages to pupation was 28 to 30 days at 18 ° C to 20 ° C and 26 to 27 days at 24 ° C to 25 ° C.

Doll

The moulting to the pupa is initiated by the previously lethargic larva, alternately bending and stretching. The seams of the head capsule and the seams along the chest section burst. The entire front of the doll is exposed. Rotating movements to the side and beating movements of the abdomen cause the skin to be sloughed backwards. This process took over two hours in a glass tube. The doll lies on its back on the floor of the doll's chamber, and is protected from direct contact with the ground by bulges on all three chest sections and all abdomen sections. It hardly reacts to artificially generated disturbances, while insect pupae generally react with violent beating of the abdomen. The pupal stage lasts eighteen to nineteen days at 18 ° C to 20 ° C, and fifteen to sixteen days at 24 ° C to 25 ° C. The doll is white to ivory in color, on average 10.08 millimeters long and 7.20 millimeters wide. The contours of the finished insect are clearly visible.

The moulting to the imago is initiated again by stretching movements, which in this case first tear the doll skin on the legs, then the skin on the rear edge of the head and the chest section. The young beetle slowly pushes its way forward out of the shell through this hole, at the same time its hind legs strip the old skin backwards. The elytra immediately assume their final position, the hind wings remain stretched for a long time before they fold under the elytra. The hatching process itself takes about twelve to fourteen hours. The beetle then rests for about five to eight days while it gradually takes on its final color.

The beetle breaks through the wall of the breeding pear at its weakest point, usually the ground. Then he works his way through the earth to the surface. Only there does he eat food for the first time. In the experiment, young beetles eat fresh manure as food before they have hardened and left the brood chamber, but the remains of the pear dung available under natural conditions are spurned.

Fight between the bugs

The animals' lust for conflict is strong compared to other coprophage beetles. As early as the third day after the young beetles appeared, they were involved in fights (Fig. 7). The instinct to fight is developed in both males and females, and both same-sex beetles and beetles of the opposite sex are fought. When sexual maturity occurs, the disputes subside in that the males no longer drive away females and vice versa.

However, the disputes revolve exclusively around the possession of brood or food pills. They usually start with the pill owner chasing away an intruder. However, cases have also been observed where both opponents attacked each other at the same time. Normally, the pill owner climbs the opponent's back, clasps him with the middle and rear pair of legs and quickly hits the opponent's head alternately with his front legs. When trying to repel the attack, both beetles fall from the ball and the attacked person attacks in turn. Because of the intensity and speed of the fight, no individual phases can be distinguished. The opponents ball with tightly knitted legs as a ball on the floor, now one, now the other beetle lies on its back, whereby the crunch of the chitin parts can be heard. The beetle that lies on top of the other when fatigue sets in is recognized by the loser as the winner; the winner goes back to the pill. Usually the bigger fighter wins.

The disputes over food pills during the maturation process are easy to understand in terms of evolution: In the fight for food resources, the stronger or more skilful animal prevails. In the struggle for breeding pills, the successful couple constellation continues the breeding business, new partners never abuse the breeding pill as a food pill.

distribution

The warmth- loving Palearctic species has a very large distribution area. In the south they can be found around the Mediterranean Sea ( southern Europe , North Africa , Asia Minor ). However, it also penetrates northwards at hot spots. The northern limit of distribution in Europe runs through the Netherlands , Germany , Poland , Ukraine and central Russia . To the east, the distribution area extends to China. In Central Europe, the species is considered rare and occurs particularly on grassy slopes that are very sunny. In Germany, newer sites are mentioned in Bavaria , Baden-Württemberg , Hesse , Lower Saxony , Saxony-Anhalt and Thuringia , in Austria in Carinthia , Styria and Burgenland .

literature

Individual evidence

  1. ↑ a b c Sisyphus at Fauna Europaea. Retrieved August 20, 2011
  2. ↑ Sigmund Schenkling: Explanation of the scientific beetle names.
  3. ↑ a b J. H. Fabre: Souvenirs entomologiques - études sur l'instinct et les moers d'insectes 6th series, Paris 1922 Sisyphus schaefferi p. 1 ff; P. 4: Characterization of the beetle; P. 9: Finding a suitable place to bury
  4. ↑ a b Joachim Prasse. The struggles of the pill roll Sisyphus schaefferi L. and Gymnopleurus geoffroyi Fuessl. (Col. Scarab.) In the scientific journal of the Martin Luther University Halle-Wittenberg Math.-Nat. VII / 1, pp. 89-92 March 1958
  5. ↑ a b c Joachim Prasse. Food acquisition of coprophagous pills ( Sisyphus schaefferi L. and Gymnopleurus geoffroyi Fuessl. Col. Scarab.) In the scientific journal of the Martin Luther University Halle-Wittenberg Math.-Nat. VI / 3, pp. 439-444 June 1957
  6. ↑ a b c d Joachim Prasse. The development of the pill roll Sisyphus schaefferi L. and Gymnopleurus geoffroyi Fuessl. (Col. Scarab.) In the brood pear in the scientific journal of the Martin Luther University Halle-Wittenberg Math.-Nat. VI / 6, pp. 1033-1044 December 1957
  7. ↑ a b c d e Joachim Prasse. The brood care behavior of the pill roll Sisyphus schaefferi L. and Gymnopleurus geoffroyi Fuessl. (Col. Scarab.) In the scientific journal of the Martin Luther University Halle-Wittenberg Math.-Nat. VI / 4, pp. 589-614 July 1957
  8. ↑ a b Mario Zunino: "Sobre el régimen alimenticio de Sisyphus schaefferi (Linnaeus) (Coleoptera: Scarabaeidae: Sisyphini)" Dugesiana 24 (1): pp. 25-29, 2017 ISSN 1405-4094 (edición impresa), ISSN 2007- 9133 (edición online)
  9. ↑ Description of the species from ARGE SWD Koleopterologen
  10. ↑ Ulrike Hausl-Hofstätter: "On the previously known distribution of Sisyphus schaefferi (L.) in Styria. Joanae Zool. 1: pp. 61–64 (1999) as PDF

Web links

Commons : Sisyphus schaefferi  - album with pictures, videos and audio files