Species composition of orb weaving spiders. Orb weaving spiders
Family of orb weaving spiders one of the largest families in the world, it has more than two and a half thousand varieties of spiders. This family includes a variety of types of spiders, they are all different from each other both in body shape, in color, and in lifestyle. The only similar nuance is the presence in milestones of spider species belonging to this family of special growths on the front pair of limbs, thanks to which they are able to weave a special kind of web. The most common and voluminous species of spiders of this family are Araneids, or as they are also called -. Crosses live almost everywhere, but their largest number is observed in the Far East, they can mainly be found in forests and fields. They weave just huge nets, which sometimes reach as much as two meters in diameter, they are very strong and solid, if some kind of insect gets into such a web, there can no longer be any hope of saving it. In the tropics, spiders are widely known orb weaving spiders, they even weave traps up to eight meters in size, and only females do this, they are very large, they cannot be confused with anyone because of their bright, very original color. Males belonging to this species of spiders are inconspicuous and almost invisible against the background of their females, primarily due to their "compact" size. The web that such spiders spin is striking in its strength, it is very difficult to break it, and besides, it is amazingly elastic, can be stretched to a length three times its original size.
Spider spider found almost everywhere, it got its name due to the pattern on the abdomen, similar to the shape of a cross, the color of such a spider is usually black, but the pattern is made in lighter colors. Although it is not easy to find spiders, their web is found everywhere, to the greatest extent in open spaces, namely in fields and gardens. They are of medium size, males are about one and a half centimeters, females - two and a half. Females lay their eggs where, in her opinion, no danger threatens them, mainly for these needs they choose tree trunks. Quite quickly, young offspring appear from the eggs, which develop simply at a phenomenal speed, and after only a few months it already turns into quite mature independent spiders.
No less interesting for dating and Venezuelan cross, its distinguishing feature is that, unlike many other varieties of spiders, they live together. So, for example, females, laying eggs in cocoons, place them in a common nest, where they stay until the moment when spiders are born. 
In the world of arthropods, the real masters of weaving the web, by right, are the orb-weaving spiders. Where do members of this family live? What common species are found in domestic latitudes? What does the orbweb spider look like? The answers to these and other questions can be found in our article.
general description
Orb-weaving spiders, photos of which can be seen in the article, are insects whose body length reaches a maximum of several centimeters. Most members of the family have a dirty brown color. Among the orbs, spiders of a reddish and greenish hue are occasionally found.
Such insects have four pairs of legs, symmetrically located on both sides of the body. The extreme limbs have the greatest length. They are used for weaving nets.
The female orb-weaving spiders are much larger than the males. In addition, they are more aggressive behavior. For this reason, miniature males have to constantly be careful. Since an angry female is able to pounce on a representative of her own species at any time, mistaking him for a suitable victim.
Web
Giant orb-weaving spiders are capable of weaving webs that are a real engineering marvel of nature. The diameter of the web can reach the order of a meter or more. However, regardless of the size of the spider, the webs always have an identical structure.
Such insects stretch a horizontal line between the stems of plants, which acts as the base of the web. Two threads depart from it, which connect the frame to the soil. A whole series of so-called radii diverges from the center of the fundamental line. The latter form spirals, which actually form a circular web.
The creation of the above traps is carried out exclusively by female orb-weaving spiders. On average, it takes them about an hour. Males do not waste time weaving webs.
Hunting features
Orb-web spiders are passive predators. Representatives of this family are located in the central part of the spiral web and wait until the prey itself falls into their trap. Despite the presence of as many as eight keen eyes in such arthropods, which provide excellent all-round visibility, they do not have to look out for victims at all. Spiders react to the vibration of the threads of the nets by placing the claws of their tenacious paws on them.
Once in the web, the victim sticks to the threads, which are covered with a sticky substance. The more movements the prey of the orb-weaving spider makes, the less chance it has for salvation, since the body becomes more entangled in the sticky mass with each vibration. Having caught the vibration, the hunter hurries to the prey, moving along the dry threads. However, the spider is able to free itself even if it gets on the sticky part of the web.
Representatives of the family are sensible about the victims who were in the networks. If a bee or a wasp is in the web, the hunter carefully cuts off individual threads until the dangerous catch is taken away.
There are spiny orb-weaving spiders. The body of the latter is covered with hard outgrowths that protect them from victims who are able to resist. If the prey does not pose any potential danger to the spider, the hunter injects poisonous enzymes into its body through special fangs. Such substances not only reduce the activity of the prey, but also lead to the gradual digestion of its entrails.
Orb-weaving spiders do not have chewing organs. For this reason, they start “lunch” only after some time has passed, when the victim’s insides turn into a liquid state. The enzymes of the spider's venoms turn the victim's tissues into a thick mass, which the hunter happily absorbs.
Reproduction of offspring
Male orb-weaving spiders are several times smaller than females. Sexually mature individuals are especially active in finding a pair. Males obsessed with mating do not care about their own food. It is for this reason that they do not create a web.
Having found a female, males are cautious. There is a high chance that they will be eaten. After all, females quite often mistake them for prey.
After a successful mating, the males go in search of a new pair. At this time, fertilized females begin to prepare for the reproduction of eggs. Spiders form a special silk bag, where they lay their offspring. Orbweaver eggs are in a cocoon throughout the winter. With the advent of heat, young individuals appear from them.
Common members of the family
In domestic latitudes, the following orb-weaving spiders can most often be found:
- Common cross- has an abdomen that expands closer to the head. In this place there are light marks that resemble crosses. The back contains a leaf-like pattern of a dark brown hue. Representatives of the species reach a size of about 16 mm. Inhabits forest clearings, edges and clearings. Scatter the net at a height of about 2 m.
- Marble cross- has an oval abdomen, which expands in the middle part. On the surface of the body there are white spots that form oval patterns. There are reddish markings on the legs. The size of adults, on average, ranges from 15 to 20 mm. Representatives of the species build shelters in the form of rolled leaves, in which they wait for prey.
- Four-spotted cross- has a spherical abdomen, painted with four dark dots, which are located on a light background. In the back of the body is a blurry leaf-like pattern. Such spiders inhabit humid areas, living in meadows, along the banks of water bodies and wherever there is high grassy vegetation.
- striped orbworm- representatives of the species have a smooth, rounded body. The size of such insects is no more than 6 mm. The body is presented in the form of a brown cephalothorax and a light abdomen, which contains wide longitudinal black lines. Such spiders settle in places with grassy, wet vegetation. Striped spinners stretch the web low above the soil, among the grass.
Finally
So we found out what the orb-weaving spiders are. About 20 species of such insects are found on the territory of our country. We often stumble upon their large complex networks in parks, gardens and forests.
Despite the frightening appearance of the orb-web spider in the photo, the description of its life cycle debunks the myth of the extreme predatoryness of the animal and the danger to humans.
According to the international taxonomy of animals, the genus of Nephila spiders (Nephila) is included in the family, which has two synonymous names at once:
- ancient Greek Nephilidae;
- latin
In the Russian-language version of the classification of arthropods, they are called Orb-weavers.
Any of the names of these spiders fully corresponds to their abilities: if the Greek nema- and -philos are literally translated as “loving to weave”, then the Russian one indicates the circular shape of the trapping network of this category of arachnids.
The appearance of a typical representative
The entire structure of the spiders of the genus Nephila (hereinafter in the text: spiders-nephiles, or nephiles) is adapted for unhindered, easy and rapid movement.
Spider-web spider according to the photo and description has:
- incredibly long legs, allowing you to take huge steps;
- extremely low weight relative to the huge total area of \u200b\u200bsupport with widely spread paws.
The area of the end segment of the leg is so small that for it the thin fiber of the cobweb serves as a completely reliable support.
Spider weaver
Given the fantastic strength and degree of elasticity of the threads of the trapping net, it is not surprising that the orb-web spider walks along the structure it has built as easily as a person skis on snow.
When looking at its narrow and as if streamlined body, a comparison with a racing car suggests itself, next to which the sometimes huge body of a caught victim seems like a clumsy bulldozer or excavator.
A scattering of small spots of bright color on the abdomen and legs, visually splitting the body into separate fragments, perfectly disguises the predator, even located in the very center of its trap.
Where are the nephiles found
Despite the prevalence of nephil in the world, each species lives in conditions that are comfortable for it. Thus, the garden orb-web spider is considered a typical representative of the fauna of Australia.
And if a spiked orb-weaving spider (also called a horned orb-weaving spider) cannot meet a Russian citizen either (because it lives in humid and sultry tropics), then for Argiope lobata orb-weaver spider, the habitat is the semi-deserts and steppes of the Crimea, Central Asia and the Caucasus .
At the same time, the green orb-web spider (or Araniella cucurbitina) is a rare but common inhabitant of the forest, where it can be found at the very beginning of summer.
Spider Araniella cucurbitina
The most common orb-web spider found near human habitation is an ordinary cross, the details of whose life are well studied by arachnologists - biologists specializing in the study of arachnids.
About the life cycle and reproduction of nephil
Males in different types of nephil spiders can be up to 10 times smaller than the female in size. Their life also does not differ in duration - after mating, they are usually killed and eaten by recent sexual partners, with special luck, the male manages to fertilize several spiders during the season.
Sometimes they have to patiently wait a few weeks until the future "wife" sheds, during this period of life she is less belligerent.
An example of spider eggs
Carefully sealed in a dense and warm cocoon, laid and hidden in a secluded place, the eggs overwinter, so that offspring hatch from them in the spring.
Being passive predators, spiders wait for a small animal to get into the network they have built, which is killed by the secretion of poisonous glands. Its enzymes, injected upon bite, cause the body of the victim to be digested while the spider rests in the nest.
Orb-spin tetragnathoides catching a hornet in its web
After the required time has passed, it returns to suck out the liquid formed inside the chitinous shell of the prey from the action of the poison's enzymes.
About traps and catchers
The main distinguishing feature of the nephil from other families of spiders is the ability to build a trapping network of a huge area (up to 1 m in diameter) within 1 hour, which has a regular radial-spiral structure (hence the name "orb-web spider").
The weaving of trapping nets and their skillful use is the main occupation of the life of the Nefil. So, if a poisonous insect (wasp, bee) sticks to the web, the threads around the dangerous prey break. The threads that have become unusable are eaten by the spider to serve as material for a new trap.
It is a spider, because, given the preoccupation of males with the abandonment of offspring, they themselves do not knit a web, or they have it in the form of a disorderly structure with randomly tangled threads.
Ladybug caught in a web
But built by the female, it is distinguished by impeccable proportions, and the shape, size of the cells, the thickness of the thread is adjusted to the expected size and resistance of future prey. The shape and size of the grid also depends on the weather and the time of year.
In addition to sticky threads, the design of the trap also includes dry silk threads - spiders run along them without sticking.
Spider of the family araneidae
The unheard-of strength of spider silk proteins (with 5 times the tensile strength of steel wire) and its elasticity (greater than that of nylon) serve as the basis for the existence of both individual members and the entire Araneidae family.
On the danger to humans and the value of spiders for wildlife
The toxicity of the venom of orb-web spider species (any) is designed only to kill prey, therefore the chemicals included in it are not dangerous for human life, although they can cause sensitive pain.
In addition to ensuring their own survival, arachnids provide wildlife with an essential service.
They participate in the process of evolution, regulating the number of some animal species, among which the strongest and most adapted to living in given conditions survive.
As for a person, the number of certain types of insects (planting pests, disease vectors and other categories) is also important for his activities, especially when living in hot tropical countries.
Video: Amazing Spiders (Spider-web)
In the world of spiders, it is the orb weavers that have earned a reputation as the best masters of weaving webs! Moreover, in 1973, two members of the orbweb family, Anita and Arabella, were sent into space aboard NASA's Skylab orbital station so that scientists could study the process of weaving webs in zero gravity.
It turned out that even in space, the design of the web did not change; it still had the same characteristic circular shape. In the skill of weaving nets, the round rows have left their relatives far behind: in other spiders, the web does not have such a clear shape, but is only sloppy "funnel" or panels of tangled threads.
Orb-weaving spiders form a whole family Araneidae, which includes about 3000 species.
But uloboride spiders are sometimes mistakenly called orbs ( Uloboridae, several hundred species) - due to the similarity of the web. Both spinners and uloborids are widespread in various parts of the globe and weave very similar trapping nets, but these hunters kill their victims in different ways.
Insect hunters
Spiral webs of orbweavers are one of the engineering marvels of nature. The diameter of the web can vary from a few centimeters to a whole meter, but all networks have a common basic structure: a “bridge” line stretched between the stems forms a triangle along with two “anchor” threads that “tie” the web to the ground. Inside the web is a series of "radii" threads that radiate from the center and form the framework of a radial spiral, the most characteristic feature of a circular web.
It takes about an hour for a spider (more precisely, a spider, since males do not weave webs) to create this miracle.
The circular web of the orb-weaver is a real trap for insects, which, without suspecting anything, fall into it right on the fly. The orbworm is a passive predator. He sits in the center of a shiny silky spiral and waits until the "lunch" itself will fly to him.
The orb weaver has eight eyes that provide excellent visibility, although the spider does not need to look for prey at all. He learns about the replenishment of his food stocks thanks to the vibration of the threads of the web. In anticipation of prey, the orbworm clings to the web with tenacious claws, which are located at the ends of the legs. He usually sits upside down, clinging to non-sticky threads emanating from the center of the trapping Web.
Once in the web, the unlucky insect sticks to the main spiral of threads, covered with a kind of "glue". Trying to escape from the nets, the victim becomes even more entangled in the sticky mass. The spider catches the trembling of the threads and hurries to the prey along the dry threads.
If the spider gets on the wrong thread, it will free itself, but the victim can no longer get out of the sticky web.
The orb-weaver is cautious about insects caught in the web. If it is a dangerous catch, such as a wasp, it will usually snap the threads around it. Some orbweavers are armed with spikes that protect the spiders if the prey resists. When the insect is not dangerous, the spider kills it by biting it with poisonous "fangs".
The poison not only kills, but also digests the prey. The spider rarely starts eating immediately after catching a prey. First, he wraps the insect with thread and waits. The spider feeds on liquid food and cannot chew, so it injects digestive juices into the body of dead or dying prey. Enzymes corrode the tissues of the insect, turning them into a thick "soup", and the spider sucks it out.
cunning predator
Orb-weaving spiders hang their webs on the routes of insects - between plants, where they most often fly. Usually spiders come out of their lair at night, although in autumn, when the females, as they say, work tirelessly to lay enough eggs, orbs can be seen both at night and during the day. Construction begins with one thread, a kind of "bridge", which the spider stretches, climbing onto a branch.
If the spinner is lucky, this thread, fluttering in the wind, will catch on the second support - the plant on the opposite side. This process is similar to flying a kite. The spider tries to keep the first thread as long as possible, and it remakes the rest of the web almost every day.
After that, under the “bridge”, the spider attaches a second, not so tight thread and runs to the center, in order to then go down on a new thread. It turns out a U-shaped frame - the basis of the web. Two "anchors" connect the base of Y with each stem, thus forming, together with the "bridge", a triangle - the outer part of the web. Then the spider begins to weave dry radial threads, diverging from the center to the edges. There are about 20 such threads.
When the work comes to an end, the spider weaves a wide auxiliary spiral from the center to the edge. This is dry silk, which serves as a platform for the spinner during the construction of a trapping spiral going to the center. The trapping spiral has more turns than the auxiliary one, which the spider removes in the course of work.
Building a web takes about an hour, maybe two. After the spider has caught and eaten the prey, the hunter returns to his lair, hidden among the foliage. The spinner sits there all day until the next evening. Then the spider, or rather the spider, leaves the shelter to inspect the net. If the web is beyond repair, the orb-weaver eats it, and processes the absorbed proteins into silk, from which weaves a new web.
Some types of spinners add thin threads to the design, forming a zigzag pattern. They probably distract the attention of potential prey, which, thanks to them, do not notice the trapping net until it is too late. Uloborid spiders do not weave sticky trapping coils. Their web is an unusually thin thread that clings to prey, like one half of a Velcro fastener is attached to the other. In addition, uloborids suffocate the victim with a tight cocoon.
careful courtship
Orb weaver males are much, about 10 times smaller than females. Adult spiders, obsessed with the goal of finding a mate, stop caring about food. But, having found the web of the female, the spider must exercise maximum caution.
One wrong move - and the female will take him for prey! After mating, the male looks for a new pair, while the female takes care of the production of eggs. The spider lays them in a dense silk bag. The offspring of orb-weavers, having wintered in their "cocoon", will be born in the spring.
The web has incredible elasticity. Its thread can be stretched five times without breaking!
The circular web is virtually invisible unless sunlight hits its lustrous silk and illuminates an intricate spiral of threads, each a fraction of a millimeter thick.
Spider silk is not only used for weaving webs. The spider wraps its prey in a silken blanket and waits for the poison to take effect before eating.
It is said that Carpathian peasants used pieces of cobwebs as an antiseptic, treating wounds with them. Well, in the near future, spider silk may well become a fairly familiar material.
In terms of such a parameter as tensile strength, the web thread can be compared with steel, and the fabric woven from the web of orb-weavers is stronger than Kevlar ™ fiber. In addition, the moistened web shrinks, so it is likely that it will be possible to make artificial muscles from it.
Scientists are working on deciphering the genetic code of the proteins that make up the orb weaver's web
Araneus ventricosus to learn how to produce such strong threads industrially.
The family of araneomorphic spiders includes more than 3000 species, united in 170 genera. Diverse, unusual, bright - these are the main characteristics of this family.
One of the largest families, it is second only to jumping spiders. Despite their belonging to the same family, it should be noted that all orb-weaving spiders differ both in appearance and in their way of life. And only one characteristic remains unchanged: specific growths on the front pair of limbs, thanks to which spiders weave an unusual web.
One of the most common and largest species belongs to the family of orb-weavers - crosses.
The appearance of spiders
Representatives of this family have a relatively large abdomen and a soft external chitinous skeleton. Spiders are medium in size - 5-8 mm. As usual, the female orb weaver is usually larger than the male. Not surprisingly, males are sometimes afraid to approach females for fear of being eaten.
The color of the spider can be varied, with or without an intricate pattern, but most often there are light brown orb-weaving spiders with a specific pattern on the abdomen.
The body of a spider is composed of two parts: the prosoma and the opisthosoma. On the front, which is popularly known as the cephalothorax, there are six pairs of limbs. The two front pairs are chelicerae and pedipalps, and the last four are walking legs. There are 8 eyes in two rows.
The abdomen of an arthropod is soft and elastic. It has an oval shape, pointed at the end. The size of the abdomen is quite diverse, which is influenced by many factors. After eating or before laying eggs, the abdomen reaches an immense size compared to the usual state. The spiracle is located in the middle of the abdomen.
Where do Orb Weavers Live?
Orb-weaving spiders inhabit almost all corners of our planet. Their habitat depends on the presence of insects that these cute creatures eat. Shrubs, gardens and orchards are ideal places for these spiders to live. Plants attract a large number of insects, which spiders love to eat so much.
The web of orbs is a wonderful marvel!
Everyone who has heard at least once about the spinners is probably aware of their amazing feature of weaving a web. Unlike many other families, Orbweavers do not strain themselves with a long and difficult process of searching for food. They pull the web and wait until the victim deigns to get into the network. Every day, orb-weaving spiders rebuild their webs, because the new web is more elastic, high-quality and catchy. The web of orbs is wheel-shaped, the threads are stretched radially. These threads are not sticky and serve as a base. Additional sticky threads are adapted to them. One strong thick thread that runs through the entire network is called a signal. In whatever place of the web the spider would not be, waiting for its prey, it holds this thread with two legs. Feeling the barely perceptible vibrations of this thread, he understands - dinner is served!
Man and Orb Weavers
Not surprisingly, Orb Weavers are typical predators and good hunters. Thanks to this quality, they are assistants in the household. They hunt in a variety of ways, ridding gardens and orchards of insect pests. It is worth mentioning that the webs of these arthropods play an aesthetic role, causing delight with their grandeur and uncomplicated beauty.
Spider-cross - the most famous representative of the orbs
Among the family of orb-weavers there are those familiar to us - crosses.