How spiders are born: from laying eggs to hatching

Order: Araneae = Spiders

...The reproduction biology of spiders, in terms of the complexity and originality of the observed phenomena, surpasses everything that is characteristic of other arachnids, and this is again associated with the use of webs.

Sexually mature male spiders are usually very different from females in their lifestyle and appearance, although in some cases males and females are similar. Usually the male is smaller than the female, with relatively longer legs, and sometimes the males are dwarf, 1000-1500 times smaller in volume than the females. In addition to size, sexual dimorphism is often manifested in certain secondary sexual characteristics: in the bright pattern of males, in the special shape of individual pairs of legs, etc. Males, as a rule, are found less frequently than females, and in some species they are not found at all. At the same time, the virgin development of eggs in spiders appears to be a rare exception. In tenet spiders, sexually mature males usually no longer build trapping nets, but wander around in search of females and are caught in the female’s nets during a short mating period.

The internal organs of the reproductive system of spiders generally have a fairly common structure. The testes are paired, convoluted vas deferens are connected near the genital opening, which in the male has the appearance of a small slit. The ovaries are paired, in some cases fused at the ends into a ring. Paired oviducts are connected into an unpaired organ - the uterus, which opens with the oviductal opening. The latter is covered by a folded elevation - the epigyne. There are seminal receptacles - sacs from which the tubules extend to the excretory part of the genital tract and to the epigyne, where they usually open independently of the ovarian opening.

The copulatory organs are formed on the male's pedipalps only during the last molt. Before mating, the male secretes a drop of sperm from the genital opening onto a specially woven arachnoid mesh, fills the copulatory organs of the pedipalps with sperm, and during mating, with their help, introduces sperm into the seminal receptacles of the female. In the simplest case, on the pedipalp tarsus there is a pear-shaped appendage - a bulbus with a spiral spermatic canal inside (Fig. 35.5). The appendage is extended into a thin spout - an embolus, at the end of which a canal opens. During mating, the embolus is inserted into the female's seminal receptacle. In most cases, the copulatory organs are more complex, and the ways of their complication can be traced within the order and are somewhat different in different groups of spiders. Usually the tarsus of the pedipalps are enlarged. The articular membrane of the bulbus turns into a blood receptacle, which, at the moment of mating, swells like a bubble under the pressure of the hemolymph. The spermatic canal forms complex loops and opens at the end of a long embolus, tourniquet or other shape. There are often additional appendages that serve for attachment during mating. The structure of copulatory organs in detail is very diverse, characteristic of individual groups and species, and widely used in the taxonomy of spiders.

The male fills the pedipalp bulbs with seed shortly after the last molt. The sperm mesh has a triangular or quadrangular shape and is suspended horizontally. The male immerses the ends of the pedipalps into a drop of sperm secreted onto it. It is believed that sperm penetrates through the narrow canal of the embolus due to capillarity, but it has now been established that at least in forms with complex copulatory organs there is a special seminal suction canaliculus. In some spiders, the male does not make a web, but pulls one or several webs between the legs of the third pair, releases a drop of sperm onto the web and brings it to the ends of the pedipalps. There are also species whose males take sperm directly from the genital opening.

The male, with copulatory organs filled with sperm, goes in search of a female, sometimes covering considerable distances. In doing so, he is guided mainly by his sense of smell. He distinguishes the odorous trail of a mature female on the substrate and her web. In most cases, vision does not play a significant role: males with blurred eyes easily find females.

Having discovered a female, the male begins “courtship”. Almost always, the male’s excitement manifests itself in certain characteristic movements. The male twitches the threads of the female's net with his claws. The latter notices these signals and often rushes at the male as prey, causing him to flee. Persistent “courtship,” sometimes lasting for a very long time, makes the female less aggressive and prone to mating. Males of some species weave small “mating nets” next to the female’s snares, into which they lure the female with rhythmic movements of their legs. In burrow-dwelling spiders, mating occurs in the female's burrow.

In some species, repeated mating with several males and competition between males is observed, which gather on the female’s snares and, trying to get closer to her, fight with each other. The most active one drives away rivals and mates with the female, and after some time another male takes his place, etc….

Spiders - what are they: types

Researchers know about 42 thousand species of spiders. Spiders can be divided into three large suborders, which differ mainly in the structure of the jaws, or more precisely, in the position of the chelicerae relative to the longitudinal axis of the body.

Suborder Orthognatha

More often, representatives of this suborder are called migalomorphs. They are characterized by the presence of thick hairs, large sizes and a primitive structure of the jaws - the claw is directed downwards and grows only on the upper jaw. The respiratory system is represented by pulmonary sacs.

The majority of mygalomorphs live in warm climates. They make burrows underground.

Orthognatha includes:

• tarantula spiders
• funnel spiders
• ctenizidae
• digger spiders

Representative of the suborder Araneomorpha

Suborder Araneomorpha

Almost all other species of spiders known to naturalists belong to the large group Labidognatha or Araneomorpha. They differ in that both jaws are equipped with claws. The respiratory system is represented by the trachea.

Types of spiders that catch prey without a net:

• crab spiders
• jumping spiders
• wolf spiders

Types of spiders using a trapping net:

• linifid spiders
• web spiders
• funnel spiders, or house spiders
• long-legged spiders
• orb weaving spiders

Among the araneomorphic spiders, there are also those that are not capable of producing cribellum, the substance from which spiders produce strong web silk, and those that produce it.

Suborder Mesothelae

Lyphistiomorphic spiders are distinguished by the fact that the chelicerae are spread out to the side rather than pointing downwards. This position is considered more evolutionarily advanced. But this suborder is considered the most primitive; traces of it were found in Carboniferous deposits. Spiders have archaic pulmonary sacs and four pairs of arachnoid warts, which have not yet been moved to the end of the abdomen. They live in earthen burrows that are closed with a lid. Signal threads radiate from the minks. Although one species prefers caves, where it makes web tubes on the walls.

These include:

• arthropod spiders
• primitive arthrolycosid spiders
• primitive arthromigalid spiders

Blue tarantula spider

Wolf spider: keeping at home

The wolf spider tolerates captivity well. Most prefer to have females, because they live in captivity for up to 4 years and can produce offspring every year. Males live only 2 years; they die quite quickly upon reaching sexual maturity.

To keep a wolf spider you will need an aquarium with a volume of 10-20 liters. It needs to be filled with forest soil or peat, the substrate layer should be 6-12 cm. The following conditions must be created in the aquarium: temperature at 25-30 ° C, humidity - 75-80%.

You can feed the wolf spider with live food (crickets, flies, mosquitoes, cockroaches, beetle larvae) and dried crushed insects. It is important to provide access to water.

All about spiders

1. There are approximately 40,000 species of spiders in the world.
2. The life of each spider is such that in a year it kills approximately 2000 harmful insects that inadvertently fall into its sticky webs. Basically, the victims of many spiders are flies and mosquitoes.
3. If you read everything about spiders, you will know that the size of these creatures, depending on their variety, can be from 0.4 mm to 10 cm. Moreover, the span of the spider’s limbs often exceeds 25 cm.
4. The color and pattern on different types of spiders depends on the structural structure of the integument of hairs and scales, as well as on the presence and localization of different types of pigments. In this regard, such creatures are painted both in a dull monochromatic color and in a bright tonality.

Body structure

These amazing creatures have 2 sections of their body. This is the abdomen and cephalothorax, which are connected to each other by a thin membrane. If you carefully examine the spider, it becomes clear that arachnids have a cephalothorax with a certain division into the thoracic and cephalic parts, provided by a thin groove.

On the head of each spider there are organs such as chelicerae, which are formed by the first pair of limbs; pedipalps, which are formed from the second pair of limbs, eyes and mouthparts. These are the characteristics and descriptions of each representative of the arachnid genus.

What will be interesting for children is that spiders do not have a complete circulatory system. They also don't have blood. It is replaced by lymph.

As for the spider’s brain, it occupies on average a quarter of the total volume in its body.

Spiders have a heart, but it has a peculiar structure and consists of 3 or 4 holes. Through these openings, lymph enters the heart area, after which it flows throughout the body, ending up in the areas between the internal organs.

The respiratory organ of spiders also has a unique structure. The respiratory system of such creatures consists of pulmonary sacs, which are made in the form of plates resembling books.

Each representative of arachnids has 8 legs, and each leg has 6 knees.

Habitat

Spiders are ubiquitous in the world and live on all continents of the globe.

Interesting spiders do not live only in areas where the surface of the earth is hidden under ice all year round.

Ten most common myths about spiders

Arachnophobia (fear of arachnids) is one of the most common human phobias. However, most people are afraid of spiders not because they are poisonous or dangerous, but only because they are smaller than other creatures living on our planet, similar to people and simply disgusting. This is probably why there are many myths about them that are passed down from generation to generation. We bring to your attention ten of the most common myths about spiders:

10. Absolutely all spiders weave webs.

You will be surprised, but only half of all known species of spiders use webs to catch prey - all the rest actively hunt, stalking their prey, as most animals do.
There is a type of spider that does not weave a web, but shoots it directly at its prey, or shoots it into the air, and then waits for the prey to fall into it. Representatives of another type of spider - Trapdoor spiders - construct a kind of hatch in which they hide until the prey is within reach. 9. Spiders can live in human hair

The appearance of this myth, popular in the 50s of the last century, is associated with the fashion for tall women's hairstyles with a bouffant, similar to a beehive.
These hairstyles were quite complex and expensive, so it was assumed that women rarely washed or combed their hair, making them ideal nests for spiders. 8. Spiders don't get caught in their webs.

In fact, they can, because they have no immunity to their own stickiness.
They just move very carefully along their web so as not to get stuck. In addition, it is not sticky everywhere: some types of spiders, for example, weave webs in which only the circular threads are sticky, and along the ray threads they move unhindered. For a spider to get caught in its own web, it would have to land on more than one drop of glue, which is unlikely. 7. “Don't kill him! Let me better let him out into the street!”

Surely you have heard something like this at least once from a compassionate animal lover.
Don't be fooled by him. The fact is that house spiders (mostly harmless to humans) cannot survive outside - they are adapted to life indoors and will freeze to death outside. Therefore, by releasing them onto the street (even with good intentions), you absolutely doom them to certain death. 6. Spiders can lay their eggs under human skin

Let's dispel this myth too.
Firstly, spiders simply physiologically cannot do this: unlike some types of wasps that lay their eggs inside other animals, spiders simply have nothing to introduce them with. Secondly, spiders care very seriously about their offspring, so they never lay eggs where there is even the slightest threat. They do this in secluded, hidden, protected places. 5. There is always at least one spider within a radius of almost one meter from you

The birth of this myth is associated with the name of archaeologist Norman Platnik.
In one of his articles in 1995, he wrote: “...wherever you are reading this book, there is probably a spider no more than a few meters away from you...”. This statement was perceived as a fact, although the author was simply speculating. Time passed, “a few meters” was replaced by one meter, the word “probably” disappeared altogether, and by 2001 these lines were already quoted as a fact. 4. Female Black Widows (Latrodectus mactans) eat their males after mating.

This is not so much a myth as it is rather misinterpreted information.
The females of some species of spiders of this genus actually eat the males, but this happens much less frequently than many people think. Of all the existing species of spiders of the Black Widow genus, only representatives of some species do this, and then only when hungry (and this, you see, is not uncommon in the animal world). The size of the males of this genus is less than one-fourth the size of the female’s body, and during mating the males must be very close to her mouth, which in turn makes it very difficult to escape (although some still manage to somehow manage to escape). In a word, the rumor about this is greatly exaggerated, and only a few Black Widows succeed in eating males. 3. Over the course of a year, a person accidentally swallows a number of spiders

This myth began because one woman (Lisa Holst) decided to prove that people can believe almost anything they read on the Internet.
Having created a newsletter with false facts (taken from the book “Facts and Fictions about Insects”), she sent it to email addresses and, in principle, proved her point, since this myth is one of the most common. 2. Harvesting spiders have the most potent venom.

You may have heard this myth too: harvest spiders supposedly have the most powerful venom, but they do not have fangs with which to inject it.
We hasten to say right away that “haymaking spiders” do not exist as such - there are a large number of different insects that are meant by this name. Moreover, some of them (such as long-legged mosquitoes or haymakers) are not even spiders, while others have no poison at all. In fact, when talking about hay spiders, people most often mean long-legged spiders (Pholcidae) - they have poison, but it is completely harmless to humans. 1. Everything you know about the camel spider

This myth was circulating on the Internet several years ago. Allegedly, the length of these creatures (they have several scientific names - phalanges, salpugs) can reach 30 cm, they can run at a speed of 40 km/h with screaming sounds, hide on the bellies of camels and are terribly poisonous. There was even a rumor that one such salpuga killed a soldier who served in Iraq. In fact, salpugs (phalanxes), of course, belong to the class of arachnids, but they are not spiders. They rarely reach sizes larger than 15 cm; the fastest representatives of the phalanx squad run at a speed of no more than 16 km/h and are not capable of everything that is said in the myth about camel spiders. But meeting him, of course, is unlikely to make you happy. ...and yes, just in case, look around and see if there is any representative of the arachnid class hanging over you

Spider in the house: good or bad

Spiders are not pets. They live in the wild, but can easily settle in a house or apartment if the living conditions are suitable for them and food is constantly available. By understanding what spiders feed on, you can prevent them from appearing in your home. Favorite delicacies of arthropods:

• mosquitoes;
• cockroaches;
• flies.

The answer to why there are many spiders in the apartment is simple - the more of these insects there are in the house, the more hunters for them will appear. The solution to the problem is simple - tighten cleaning, including in hard-to-reach places.

How to get rid of a house spider in the house?

Despite the fact that the spider is harmless to humans and is even useful because it destroys insects in the house, not everyone will be happy with such a neighborhood.

To get rid of spiders in the house, you need to regularly carry out wet cleaning, paying special attention to dark corners and hard-to-reach places (cornices, baseboards, back walls of cabinets, etc.). You can use a vacuum cleaner wand to clean hard-to-reach places. You can use a vacuum cleaner tube to clean hard-to-reach places

You can use a vacuum cleaner wand to clean hard-to-reach places.

Before you think about how to get rid of spiders in the house, you should find out who serves as their food source, and who needs to be kept in company with arthropods. Fighting spiders does not always happen with the help of pesticides. To begin with, try simple and effective methods, as they do not form colonies and do not multiply at record speed.

• Find out the reason for the appearance of spiders and start fighting small insects.
• Get rid of cobwebs with a broom or vacuum cleaner. Don't forget to empty the contents of the garbage disposal outside, otherwise the spider will get out and continue to weave its webs. The simplest device for collecting cobwebs is a stick with a rag wrapped around it.
• If there are too many spiders, they have time to lay eggs, which you need to look for in secluded places, for example, on furniture near the walls. Sweep them up and flush them down the drain.
• Seal cracks and crevices, glue wallpaper where necessary, install mosquito nets and screens on ventilation grilles.
• Regular cleaning will prevent the appearance of spiders.
• After repairs, usually not a single spider remains, since the smell of paint and varnish materials is unbearable for them.
• Spiders are repelled by the pungent smells of chestnuts, hazelnuts and oranges, mint, and eucalyptus. You can crush the fruits and scatter them around the room or add drops of the substance to a spray bottle and spray the apartment regularly.
• Sprinkle diatomaceous earth on the baseboards; when the insect gets on it, it quickly dies.
• Regular vinegar is highly effective. Add a few drops of vinegar to the water, pour into containers and place around the apartment.

Chemical repellents for spiders in the apartment

If the number of spiders in your home has become alarmingly large, you cannot do without the use of chemicals. Universal aerosols against spiders are ineffective. Use household preparations based on pyrethroids. Be careful when spraying, remember to take safety precautions and follow the instructions. Also remember that the poison only works when it gets on the spider’s body.

A product that is suitable for fighting spiders – “Dobrohim FOS” – has proven itself well. The drug is an acaricidal agent that allows you to destroy arachnids with a 100% guarantee. The product is safe for people, but has a lethal effect on insects.

It happens that the use of aerosols is impossible for some reason - small children, pets, and so on. Then it is advisable to use pills - traps, inside of which poison is placed. In addition to other control methods, it is recommended to place glue traps in corners, behind cabinets, and under low furniture.

To prevent such a problem as a lot of spiders in the apartment from arising, regularly carry out high-quality cleaning, ventilate and beat out mattresses and pillows - this way there will be less dust at home. Wash lighting fixtures, pay more attention to hard-to-reach places - in corners, under furniture, in closets, especially if you rarely use them. And remember that the spider is more of a useful creature than a pest, so let all methods of control be gentle.

Big spider in the apartment

If you notice only one spider, you can carefully take it outside. The house spider is not capable of causing harm to humans. But what to do if there are a lot of spiders, and this has become a problem? In this case, both chemistry and folk remedies will help in the fight against them.

How spiders get into the house

Arthropods appear in an apartment or house by penetrating:

• through windows;
• through doors;
• through the attic;
• through the basement;
• on clothes;
• on flowers or purchased plants brought from the street.

How good is this or, on the contrary, bad for a person and the main thing is whether it is necessary to kill uninvited “guests” if the fate is that spiders actively reproduce, littering the house with cobwebs and traces of vital activity. In fact, a lot depends on the superstitiousness of the home owners.

If they believe in omens, then most likely they consider spiders to be symbols of good luck, income, and success. However, signs associated with spiders are not always positive. Many, not knowing for sure whether spiders in the house are good or bad, believe that they can bring bad luck, illness, and even provoke adultery.

How does mating happen?

The cage of fattened individuals is always carried out on the territory of the female. Experts recommend preparing the terrarium immediately. The drinking bowl and all decorations are removed from it, leaving only an object that serves as a refuge for the spider.

The soil is moistened. Bring the percentage of air humidity to 60%. The terrarium must have good ventilation.

For individuals of the burrow type, the depth of the litter is increased to 15 cm. Females will begin to rebuild the burrow, equipping it with a nursery for nymphs. The soil is combined from coconut substrate, vermiculite, sphagnum. Breeding tarantula spiders at home requires following certain rules.

The spider is placed in a terrarium with a female. He begins to explore the territory. It takes him some time to do this. You should not push him with tweezers or direct him towards the female. At this time, the spider may be in its shelter or sitting on the litter; she waits for manifestations of activity from the male. When spiders are ready to mate, they call for a female by tapping their pedipalps on the ground.

The male slowly approaches the spider. If she is ready for fertilization, then there will be no aggression from her. She raises her upper limbs into a vertical stance. At the same time, a gap opens in her epigastric groove in which the ovaries are located. In female tarantulas this is a paired organ.

The spider holds the female in an upright position with its tibial hooks. It touches the slit in the furrow with its pedipalps, releasing seminal fluid from the bulbs. After mating is completed, the tarantula lowers the female and quickly runs away so as not to experience her aggression.

At this point, keepers need to react quickly; disconnect the male from the female, remove him from the terrarium. Otherwise, you may lose it.

The process of female fertilization does not end there. Another male is placed next to the spider. Sometimes mating of tarantula spiders continues until the female becomes overly emotional.

Spiders reproduce in natural conditions once a year. When keeping at home, you must follow these rules.

Making a nest

More precisely, it’s not us who make things, but the mother of spiders. These arthropods develop in eggs. The spider keeps it securely in a cocoon.

But first things first. First, the future mother spider weaves a nest. A “backing” is woven under the eggs. It is a soft web. Eggs are laid on this web. And the top is covered with another layer of cobwebs. The result is pancakes made from spider webs with an egg-shaped filling between them.

After the pancake is ready, the spider turns it into a cocoon. And attaches it to the wall of the nest. In it, the eggs mature, and the baby spiders inside are preparing to be born.

Number of spiders

How many spiders are born at a time? Given that the clutch consists of a fairly large number of eggs, it is difficult to predict how many babies will see the light of day. A spider can weave one cocoon and lay 5 eggs in it. Or he can work on several with a total number of eggs of about a thousand. This happens extremely rarely. Most often, the number of cocoons with clutches reaches 10. Now imagine that each of them contains five eggs. And this means that fifty baby spiders will be born.

Spider Mom

Speaking about how spiders are born, one cannot fail to mention the “merits” of their mother. The spider is the guardian of her babies. She valiantly guards the cocoon, and if anyone dares to encroach on the treasure, death awaits him. While the babies are developing in the eggs, the spider loses a lot of weight. After all, she doesn’t go out to get her own food. As a result, her abdomen shrinks very much and becomes wrinkled. The spider often dies near the nest, without waiting for the children to hatch.

If the new spiders in this world are lucky and they find their mother alive, then a better guard will not be found. A mother is able to recognize her children by feeling them with her pedipalps. And woe to the spider that finds itself in the zone of her groping. At best, he'll kick you out. Otherwise, he will kill. This is a threat to your beloved children.

Birth of spiderlings

How are spiders born? Let's start with how the baby develops. The spider lies in the egg, right on the yolk of the egg. And it comes together in one heap. Before this it was segmented. And then all his body parts—segments—merged together. And the spider began to resemble a normal arthropod creature: there was an abdomen, eight legs, and a head, gradually turning into a chest, with eight eyes.

Our baby has grown up. The egg is cramped for him. This is where the shell of the egg bursts. Or the spider itself makes its way to the exit, breaking the shell. If the mother is alive and nearby, she will help the offspring get out. If not, then the little ones should sit in the remains of the shell and wait for the first molt. Little spiders are funny: they are hairless and colorless. They cannot eat or weave webs on their own.

Brief description of eggs and cocoon

Spiders lay eggs in a web cocoon. It consists of two layers, between which there is a loose layer.

The web protects the masonry from the following dangers:

• drying out;
• mechanical damage;
• bacteria;
• parasites;
• fungi;
• temperature jumps.

Basically, spider eggs consist of a nutritious yolk. They are covered with chorion and vitelline membrane. Quite elastic to the touch. With strong mechanical stress, the shell is very easy to destroy.

The color of the shell may vary depending on the species. In the nests of different species you can find almost all the colors of the rainbow, in addition, these colors can be very bright.

Some eggs are poisonous to mammals. Moreover, their toxicity does not depend on the degree of toxicity of the spider that carried them. An animal that eats such a clutch may die.

The cocoon consists of a web, which is why it is painted white, but can have different shades. Sometimes spiders coat their webs with a special enzyme, which makes the shell dense. It protects the masonry from moisture and bacteria.

Spiders can hide cocoons:

• on the ground;
• under fallen leaves;
• under stones;
• attach to branches.

In some species, the web does not reflect ultraviolet light or reflects only some spectra, due to which the cocoon becomes visually less noticeable among the foliage.

Spider eggs and cocoons

In the photo - the opened egg cocoon of the orb-weaving spider Argiope bruennichi

). On the outside, the eggs are protected by two dense shells with a thick, loose layer between them. In the photo, the outer shell of the cocoon has been removed, and the loose layer is clearly visible. These layers consist of special types of webs and protect the masonry from mechanical and temperature influences, as well as from drying out. Argiope Brünnich itself is also sunny yellow; for its bright warning color it is often called the wasp spider.

Argiope Brunnich with a cocoon. Photo © Michael Hohner from mhohner.de

The eggs of all spiders are relatively large, rich in yolk, covered with a vitelline membrane and chorion. The female usually lays a clutch several days or weeks after mating, with the number of eggs laid varying greatly depending on the spider species. Thus, in the tiny cocoon of the Pyrenean spider Telema tenella

Only one egg is hidden, but usually the clutch of spiders is richer and contains 30–50 eggs. And some species have hundreds of eggs in their clutches (for example, the same Argiope Brünnich).

Since spider eggs are in a cocoon, they are rarely seen. And there is something to see: you can collect a collection of eggs of all the colors of the rainbow! This was done in the laboratory of Glenn King at the Pain Research Center at the University of Queensland (Australia). Scientists are studying a variety of poisons in the hope of using them to treat nervous system disorders. It turned out that spider eggs can be toxic and deadly to mammals, and the level of toxicity does not correlate with the poisonousness of the spider itself. Less is known about the color of eggs: it is still unclear what the mechanism of its formation and biological meaning are.

Spider eggs from the collection of the Pain Research Center. Left

— eggs of a spider of the genus
Holconia
(family Sparassidae),
on the right —
eggs of a spider
Cyrtophora
(family of orb-weaving spiders). Photo from Glenn King's Twitter

The variety of egg cocoons is great and depends on the spider’s lifestyle. Female spiders that live in burrows lay their eggs there. The female first makes a special dense plate from the web, on which she places all the eggs, and then covers another, carefully and firmly fastening all parts of the cocoon along the edge. In representatives of some families, such flattened cocoons are securely attached to the soil or to the wall of the nest (for example, in spiders of the families funnel-web spiders, tube spiders, gnaphosids, sac moths, side walkers). Wolf spiders tear off the finished cocoon, consisting of two plates, from the substrate and make an additional layer of web on top, as a result they get a cocoon in the shape of a ball, which the female carries with her, attaching the web to the end of the abdomen.

The huntsman spider from the family Sparassidae carries a flat cocoon in its chelicerae. Photo © Melvyn Yeo from deviantart.com

Female spiders of the genus Pisaura

(family Pisauridae) make the entire spherical cocoon from the main plate, leaving a small hole at the top for laying eggs, which is subsequently covered with a tiny covering plate.
Web spiders weave a cocoon while on the web. In many species of tentacles, the cocoon is spherical, with indistinguishable seams between the main and covering plates and consists of a loose, cotton-like web. On top of such a loose shell, the female spider can make a second protective layer of denser web. Cocoons can also have a more complex structure. For example, in Agroeca brunnea
(family Liocranidae), a goblet-shaped cocoon, attached by a stalk to the stem or branch of the plant, is divided by a transverse septum into egg and brood chambers. The female places eggs in the first, and the spiderlings move into the second, where they remain for another 2–3 weeks after hatching and molt.

Cocoon of Agroeca brunnea

outside and a diagram of the section, where you can see the chamber with eggs, the septum and the brood chamber. Photo from en.wikipedia.org, drawing from entomologa.ru

The following pattern can be traced in the structure of the cocoon: its walls are thin and fragile if the clutch is inside a reliable and durable nest or the female carries it with her. In other cases, the eggs need additional protection in the form of a dense thick shell - like the argiope, which places the cocoon openly on its web. However, such a powerful cocoon wall can serve as a serious obstacle for hatched spiderlings. But Argiope spiders can dissolve the internal fibers of the cocoon with the help of enzymes. And female tarantulas themselves open the cocoon with the help of chelicerae, thereby helping the spiderlings get out. Let us remember that wolf spiders, which include tarantulas, carry a cocoon with them and actively protect it.

If spider eggs can be painted in bright colors, then cocoons are most often white (the web is white), although they can have different shades. In Argiope Brünnich, the cocoons have dark green stripes; in spiders of the genus Zelotes

(family Gnaphosidae) have pinkish cocoons, orb-weaving spiders
Cyrtarachne
and some species of the genus
Araneus
, as well as nephilous orb-weaving spiders have golden cocoons,
Cyrtophora
have greenish cocoons, and wolf spiders of the genus
Pardosa
have greenish-blue cocoons with a white seam in the middle. Scientists do not yet know how such coloring is achieved; it is only known that the web of trapping nets may contain pigments that give it color (but it is usually unpigmented).

To camouflage the cocoon, some spiders can encrust it with particles of soil and plants, making it almost invisible against the background of the substrate (for example, Agroeca brunnea

).
The spectral properties of the arachnoid membrane can also make cocoons invisible. For example, in many species of spiders (for example, Peucetia viridans
from the lynx spider family), the reflectance spectrum of the cocoon web is highly red-shifted, giving the cocoons a brownish appearance.
This allows them to blend in with the fallen leaves among which the spiders hide them. In spiders that live in good lighting conditions (for example, Zosis geniculata
from the uloboridae family), the web practically does not reflect ultraviolet radiation, which makes it possible to camouflage the cocoon against the background of the substrate. All these “tricks” probably additionally help spiders hide their cocoons from potential predators (for example, ants) and parasitoids—riders that lay their eggs in the cocoon.

A variety of shapes and colors of spider cocoons in Costa Rica. Image from G. Barrantes et al., 2013. Variation and possible function of egg sac coloration in spiders

There is an opinion that spider cocoons were originally formed to hold the clutches on the substrate, and their protective role is secondary. But, one way or another, over time, the masking and protective role came to the fore. A dense layer of web protects the masonry not only from mechanical, temperature influences and drying, but also from bacteria and fungi - the web has bactericidal and fungicidal properties.

Photo from the site nashzeleniymir.ru.

Ira Demina

How spiders lay eggs

Spiders are known for eating the males after mating. This is necessary so that the body is saturated with a sufficient amount of nutrients that are needed to maintain pregnancy.

This is why females live much longer than males, and each clutch significantly shortens their life.

Females of some species spend all their resources on protecting their offspring, and therefore die from exhaustion. Other species do not care about their offspring at all.

After fertilization, the female begins to weave a cocoon. Its shape and strength depend on whether it will be placed in a secure nest or in an open area.

The cocoons that are located outside the nest have much denser webs. Some females wear the cocoon on themselves. From the outside it may seem like a spider is crawling with an egg on its belly. The mother protects the offspring until the spiders come out.

Burrowing species weave a cocoon from two web plates. They lay it on a smooth web sheet, and then tie it with a covering web on top.

Other species weave a round bag in which they leave a small hole. The spider lays eggs through it. Afterwards the hole is closed with cobwebs.

Tenet species hang a cocoon on a spider web not far from their hunting nets. After laying eggs, the female stops feeding and devotes all her energy to protecting the offspring.

In this case, the juveniles stay inside the web shelter in winter, and come out with the arrival of spring. By this time, the female is already dying from cold and exhaustion.

Inside the web's shelter, spiders go through several stages of development. At first they become nymphs: the egg develops short legs.

Then, with each molt, the nymphs become more and more like small spiders. When it’s time to go outside, the juveniles tear apart the web with the help of chelicerae. Some species destroy webs using a special enzyme.

The species Agroeca brunnea creates a pear-shaped cocoon that attaches to grass or twigs. It consists of two sections. One is used for storing masonry, and the other is for molted spiderlings. The juveniles stay there for about 3 weeks.

Often the females protect and care for the cocoon. They can open the web themselves to release the molted young. Some species carry spiders on their abdomen.

Sometimes the young remain in the mother's nest until the third molt. Females of the Venezuelan cross collect cocoons together and connect them to each other.

Features and habitat of the cross spider

The cross spider belongs to the orb weaver family. The spider was given such an unusual name because of the large noticeable cross on its back, formed by light spots.

The abdomen of the “flycatcher” is of a regular round shape, most often brown, but there is also a white cross , whose abdomen is light yellow or beige. Long legs are very sensitive to the slightest vibrations of the web.

The cross spider has arranged so that the insect has a 360-degree view. However, its vision leaves much to be desired; the spider can only see shadows and vague outlines of objects.

species of cross spiders - about 2000, only 30 of them are found in Russia and the CIS, and all can boast of a pronounced cross on the upper part of the abdomen.

In the photo there is a white cross spider

The size of a female individual can vary from 1.5 to 4 centimeters (depending on the specific species), while the size of a male individual can vary from 1.5 to 4 centimeters. Another surprising thing is the mixed cavity of the insect’s body - the myxocoel, which appeared as a result of the connection of the primary cavity with the secondary one.

One of the most common types is the common cross. The female of this species can reach 2.5 centimeters in length, the males are much smaller - up to 1 centimeter. The abdomen of males is quite narrow, while that of females is large and round. The color may change slightly, adjusting to the lighting at a given time.

The spider's body is covered with special wax, which helps retain moisture. The female cross spider has reliable protection - a cephalothorax shield, on which the eyes are located.

The photo shows a female cross spider

Preferred habitats are always quite damp and humid. These can be forests, fields and meadows near swamps and ponds, groves, gardens, and sometimes human buildings.

How many eggs are laid?

Spiders lay eggs several days or weeks after mating. Their number depends on the type and size of the spider.

The least prolific species is Telema tenella. Its clutch consists of one egg. In this case, the cocoon has a size of about 2 mm.

Small-sized species lay 20-30 eggs. The most prolific are tarantulas, which themselves are large in size. These arachnids can lay up to several hundred eggs.

At most, one spider can lay about 1000 eggs at a time. Moreover, the greater their number, the smaller the sizes. Of course, not all of them are fertilized.

In addition, the mortality rate among young animals is quite high. Therefore, out of a thousand eggs, only a few dozen spiders will be born.

Sometimes females eat the cocoon. This may happen for the following reasons:

• the clutch is unfertilized (most often this happens if the male turns out to be old);
• the female considers environmental conditions unsuitable for the life of her offspring.

Thus, all spiders emerge from eggs, in which a new living organism goes through the first stages of development. To protect the clutch from external influences, the female covers it with a dense arachnoid cocoon, which retains moisture and protects the brood from sudden temperature fluctuations.

Since spiders are distributed throughout the globe, we can conclude that this method of reproduction is effective.

Feeding the cross spider

The main diet of crosses consists of a variety of flies, mosquitoes and other small insects, which it can eat about a dozen at a time. A sticky substance is first released from the spider's arachnoid wart, which only becomes a strong thread in the air.

For one catching net, a crossman can produce and spend about 20 meters of silk. Moving along the web, its owner touches only the radial threads, which are not sticky, so he himself does not stick.

During the hunt, the spider waits in the center of the trap or is located on the signal thread. When the prey sticks to the net and tries to get out, the web begins to vibrate; the hunter feels even the slightest vibration with his sensitive limbs.

The spider injects a dose of poison into its prey and, depending on the situation, can eat it immediately or leave it for later. If an insect acts as a backup source of food, the spider will wrap it in a web and hide it securely in its shelter.

If an insect that is too large or poisonous gets caught in the trap, the spider breaks off the web and gets rid of it. The spider spider avoids contact with insects that lay eggs on other insects or animals, since the large abdomen of the spider can become an excellent place for larvae.

The spider's digestion process occurs in the body of the victim with the help of digestive juice. The cross spider, like other spiders, cannot digest food on its own.

Further fate

Just as spiders are born, they sit hungry if their mother is not around. The spider feeds the babies for the first time until they moult. What should the orphan spiders do? They eat the yolk, which is prudently stored in their abdomen. And they patiently wait for the moult. Have they moulted, shed their baby skin and acquired a chitinous shell? Now you can learn to weave a web.

Rarely do any of the “babies” immediately leave their egg. Most baby spiders live in the remains of the shell for several months. And then they crawl out, and their paths with their brothers and sisters diverge forever.

True, not all representatives are like this. Crosses, for example, clump together. And they bask in the sun for a long, long time. Only then do they scatter. And tarantulas travel on their own mother. They climb onto her back and ride like that. When they grow up, the spider itself resettles its offspring. Drops them in different places from the back. Why not throw them all at once, they will have more fun together? And so that they don’t die of hunger.

By the way, about food. What do little orphan spiders eat, besides yolk? The yolk is running out, but I want to eat. It sounds terrible, but they eat their own mother’s body. Climbing out of the shell, the kids discover a shriveled, dead spider. Only they don’t know that it’s the mother in front of them. And the whole brood pounces on the food. So the spider feeds her children after her own death.

You can see how spiders are born in the photo. The sight is not the most pleasant, but it is useful for educational purposes.

Spider with cocoon

Surely many of you have met a spider running along the ground with some strange white ball stuck to its abdomen? This is how mother spiders carry a cocoon of spider webs with eggs, from which spiderlings will hatch in the future. In the photo you can see a female wolf spider (Lycosidae) with beautiful gray-brown fur and a white cocoon with spider eggs attached to her abdomen. If you look at this cocoon enlarged, it looks like a white golf ball. The eggs protruding under the cover of a dense web form tubercles similar to the bumps of a golf ball. Interestingly, the web cocoon is used for offspring even by those spiders that do not weave hunting webs, but simply hunt, like the wolf spider captured in the photo.

After fertilization, the female looks for a secluded place. There she weaves a spherical cocoon where she lays her eggs. The female wolf spider wears the cocoon on her body for several weeks, where it is attached to the tip of the abdomen using a spinneret. The rate of egg development depends on temperature, so the expectant mother begins to spend a lot of time in the sun, and not hide in the shade during the day, as before.

When a female wolf spider is carrying eggs, she spends a lot of time in the sun, as the eggs develop faster at high temperatures. Due to dehydration, she sometimes loses up to 30% of her weight! But the maternal instinct is stronger, and the female endures this torment for the sake of the offspring.

If a cocoon with eggs is taken away from a female, she will still experience anxiety for several hours and wander around the place where the cocoon was taken from her, in search of her offspring. A female whose cocoon has been taken away may carry a piece of cotton wool or even plasticine instead. There is a known case when a female Pardosa riparia, a small species, began to carry a cocoon of a much larger species of Pardosa amentata, which was four times larger than her own!

When the spiderlings emerge from the eggs, the mother breaks the cocoon with her powerful jaws-chelicerae, and the spiderlings, one by one, move onto her back. When the very first spider leaves the cocoon, it leaves a web along which all its brothers and sisters climb onto the mother. Until their first molt, they do not get off their mother's back and do not eat anything. Then the female finds a suitable damp, shaded place, the spiderlings descend to the ground and begin to live on their own.

The nervous system of wolf spiders is one of the most developed of all spider species. This is due to their rather complex lifestyle - the need to hunt prey, complex mating rituals and the process of bearing offspring.

For anyone who wants to read in more detail about the process of gestation of eggs in wolf spiders, I recommend an article on the website nature.rf

Additional photos: A few more photos of the spider with a cocoon