Species composition of orb weaving spiders

We are accompanied in life by a huge number of living beings. We love a kitten or a puppy, but a cockroach or a spider is disgusting to us, and we don’t even think about whether they are useful or harmful. We won’t say anything good about a cockroach, but let’s try something good about a spider. They live everywhere - high in the mountains, in the desert, in forests and meadows, even in water. Spiders are not found only in the permafrost of the Arctic and Antarctic. The conquerors of Everest found one of the species of spiders at an altitude of 7 km, and in the taiga there can be up to 300-350 small spiders per square meter of soil.

They have been and remain permanent neighbors of humans for many millennia. When a person first settled in a cave, spiders were already living there. But spiders, which are harmless for the most part, cause many people a superstitious fear, the roots of which go back to ancient times.

Thanks to a misunderstanding, the Apulian tarantula even became famous throughout the world. The tarantella is named after him. This dance, widespread in the south of Italy, without which not a single folk festival is complete, was born in Apulia somewhere between the 13th and 18th centuries AD. e. Its appearance is associated with a method of treating a disease that has been practiced since ancient times, from which, at the height of summer, primarily young men working in the fields suffered.

Among the many thousands of species of spiders, there are only a few whose venom is dangerous to humans. For example, the outwardly scary Zigella and Cyclosa spiders are actually completely harmless. For example, they bring more benefits to humans than harm. For example, in folk medicine, fresh spider webs have been used since ancient times as a plaster. It stops the bleeding and disinfects the wound. Some tropical spiders weave such strong webs that natives use them for fishing nets and nets. In ancient Rome, doctors often recommended that a sick person wear a spider bag around his neck to cure malaria and other diseases. Here is a similar recipe from a medical reference book compiled by a certain Watson back in 1750: “Carefully cover a live spider with bread crumb, but so as not to damage it, and let the patient quickly swallow. This is a very effective medicine...”

Spiders are combined with scorpions and ticks in the class of arachnids and belong to the phylum of arthropods, like insects and crayfish. The name is a class of arachnids and belongs to the phylum of arthropods, like insects and crayfish. The name of the class arachnids (Arachnoidea) comes from the Greek arachne - spider. An ancient Greek myth tells of a girl named Arachne who dared to compete with the goddess Athena.

Spiders are the largest order of arachnids. More than 20,000 species have been described, and experts believe that this figure will increase significantly in the future, since the fauna of spiders around the globe has been studied very unevenly and incompletely. All land is inhabited by spiders. Like insects and mites, they live everywhere, and there is literally no corner of nature where there are not some species of spiders.

To move on to a more detailed examination of spiders, let's try to immediately understand the nature of this huge order and the features of its diversity. Indeed, in all the main life manifestations that support the existence of the species - obtaining food, reproduction, settlement and surviving unfavorable conditions - spiders use webs. It is used to make a shelter and a catching device, with its help a complex mating procedure takes place, an egg cocoon is woven from it and a wintering sac on it, the young are carried by the wind, etc. The spider interacts with the outside world not so much directly as other animals, through its arachnoid adaptations that each species has to suit its life needs and the specific environment in which it lives. In other words, relationships with the environment are carried out in spiders through web activity, which, like all spider behavior, is based on instincts. A comparative study of spiders shows that the evolution of web activity, the evolution of instincts is the leading direction of the evolutionary development of spiders, in which this unique order has reached an unprecedented peak.

A clear confirmation is the nature of the diversity of spiders. Web devices represent the evolutionary series of very simple to extremely complex and sophisticated, be it egg cocoons, lairs and nests, or trapping nets. At the same time, the construction of web devices is becoming more complicated. It is remarkable that the general type of structure of the spider is firmly preserved. The sizes of spiders, coloring, external shape are different, the structure of individual organs changes, but all this endless diversity is contained within the framework of a certain stereotype. A spider is always a spider. Unity is also maintained in a number of biological features, type of nutrition, individual development, etc.

The body of spiders is divided into two sections: the cephalothorax and abdomen. There are 4 pairs of legs on the cephalothorax, and 4 pairs of eyes on the top of the head. A pair of short tentacles is directed forward; in males, the ends of the tentacles are thickened.

A characteristic feature of all spiders is the ability to secrete a special liquid from the warts at the end of the abdomen, which immediately hardens into a web. The web varies depending on its purpose. Spiders use it to make nets to catch prey, weave shelter for themselves, make a cocoon to protect eggs, and use it for dispersal.

All spiders are predators, feeding most often on insects. They get them either by lying in wait, or actively pursuing them, or using trapping nets. The shape of the trapping nets varies among spiders. To kill prey, spiders use curved hook-shaped jaws (chelicerae), with a channel inside through which poison flows into the victim’s body. (In the middle zone of our country there are no spiders that are life-threatening to humans, but the bite of some spiders can be very painful.)

After laying eggs, the female either guards the cocoon with eggs while sitting in a shelter, or carries it with her.

Young spiders emerging from eggs usually stick together at first and then scatter. In some species, they try to climb somewhere higher - on fences, bushes, trees. Here they release a small, light web, which is picked up by the wind and, together with the spider at its end, carried away into the distance. This is how the settlement of young spiders occurs. This usually happens in the fall, during the “Indian summer”, and then everywhere on the bushes and fences we see cobwebs shining in the sun.

Adult spiders die after the end of the breeding season.

Orb-weaving spider family (Araneidae)

Spiders with a thick abdomen, significantly exceeding the thickness and width of the cephalothorax. The legs are short and thick, adapted for sliding along the web.

They move slowly, and in case of danger they often fall to the ground. The fishing net is wheel-shaped, with the middle filled with mesh. Spiders sit either on a fishing net or nearby in a shelter.

Typical representatives are cross spiders (Araneus), of which there are about 20 species in the central zone of the European part of Russia. We come across their networks along the paths of gardens, parks and forests in July - August. Most often they belong to females. We provide a description of the females of the most common and widespread species.

Common cross (Araneus diadematus)

The greatest width of the abdomen is in the anterior part. Here there are light spots in the form of a cross, and on the back of the abdomen there is a dark leaf-like pattern. The legs are yellow, with dark rings. Size 14 – 16 mm. A spider waiting for prey sits in the center of the web. Inhabits forest edges, clearings, and open forests. The fishing net is spread at a height of 1.5 - 2 m.

Widespread throughout Russia.

Marble cross (Araneus marmareus)

The abdomen is oval, its greatest width is in the middle. The light (sometimes red) spots forming a cross-shaped pattern on the abdomen are steeply oval. Legs with reddish rings. Size 15 – 20 mm. A spider waiting for prey sits on the side of the trapping net, in a shelter of leaves folded up like a roof. There are more than 30 radii in the network. Habitat and distribution are similar to those of the common cross.

Four-spotted cross (Araneus quadratus)

It is similar in size and general color background to the two previous species. The abdomen is spherical, in the anterior part with four rounded light spots or with four dark dots on a light background. The leaf-like pattern at the back of the abdomen is blurred.

Found in open, damp places: meadows, swamps with tall grassy vegetation, along river banks. The fishing net has 20–28 radii. The spider sits in a shelter on the side of the net, where the signal thread leads.

Widespread throughout Russia.

Striped orb weaver (Singa nitidula)

A small spider, 5–6 mm in size, with a rolled abdomen. The cephalothorax is brown, the abdomen is light, with two wide dark longitudinal stripes.

Common in places with moist herbaceous vegetation. The fishing net stretches among the grass, not high above the ground. The spider sits on the side of the net in a shelter made of a green leaf folded into a corner.

Widespread throughout Russia.