The garden spider (Araneus diadematus) is an arachnid belonging to the genus Araneus, which is present in all parts of the world. They are spiders, which along with the others of this genus, inhabit forests, especially in growth of the piedmont.
Araneus diadematus It is also known as the cross spider, due to the shape of the spots on its back. These arachnids weave a web in an orbital shape and wait for their prey coiled in a tree or in a hole that they weave with the same web in one of the upper corners. It is a spider with excellent weaver conditions.
The females of this species have bright eyes and have yellow bands on their legs; therefore, it is perhaps the most attractive species in its garden habitat. Its legs are divided into seven segments: coxa, trochanter, femur, patella, tibia, metatarsus and tarsus..
They are carnivorous and feed mainly on insects, thus regulating their populations in gardens. In addition, the cobweb can be used by people on any wound to stop bleeding..
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The body of this arachnid is generally brownish-orange in color, and on it it shows numerous white spots whose delimitation resembles the shape of a cross, hence its other common name. This spider has bilateral symmetry and is ectothermic.
For their part, these spots can be large or small at the same time that they can merge with each other; however, the circular spot on the cross remains always. This cross arrangement of spots or dots is best observed in dark-colored individuals..
In particular, these spots or blemishes are caused by guanine cells that shine through the transparent cuticle. For its part, the shell has a dark band on the margin and in the center.
Of its legs, the four pairs of legs extend radially from the connecting shell and sternum. Each leg has seven segments, a coxa and a trochanter (short), a long femur and a patella, a stylized tibia and metatarsus, and a tarsus with three claws..
The body of this spider is bristled with thick, light-colored trichomes that look like spikes and are scattered all over the body..
The female is larger than the male. The female individuals of Araneus diadematus they can be 6.5-20mm long, while males are 5.5-13mm long.
The external sexual organs of males and females are seen in the ventral part. The male and female genital openings lie within the epigastric sulcus. Males have a pedipalp where they store sperm.
The geometry of the web that is built by the females is amazing. It is known as orbital web, which is characteristic of spiders of the genus Araneus.
It is a large spider web and has all the threads arranged vertically, with a center surrounded by 30 rays with equal distance from each other..
In addition, the woven net is in the shape of a narrow spiral on the inside, while the net becomes wider on the outside..
Interestingly, near this web of web, the female weaves a hollow structure of dense threads where she hides while waiting for a prey to fall, or waiting for a male to approach. The web is not wasted but consumed by the spider along with its prey, or while it is weaving a new web..
The vertical webs of the spider web of the cross spider have been studied to have significant asymmetry towards the bottom. In experiments, it has been shown that this spider travels faster downwards than upwards..
Therefore, this gives it a greater feeding value towards the area below the center of the web, than the nutritional importance of the part above the center of this network. The smaller the prey, the finer the capture mesh without losing its effectiveness.
-Animalia Kingdom
-Phylum: Arthropoda
-Class: Arachnida
-Order: Araneae
-Family Araneidae
-Gender: Araneus
-Species: Araneus diadematus Clerck, 1757.
The garden spider is widely distributed from littoral areas to high mountains, although it is native to the Nearctic zone. It can be found both in gardens or places where humans live, as well as in open places in nature, especially in Europe..
As for America, it is an introduced species. It is located in New England and Canada, passing through Washington, Oregon and British Columbia. This spider lives in temperate and terrestrial zones.
Also, it can be obtained in savannas and prairies. Therefore, it requires some presence of humidity in its habitat..
In the dwelling place there are usually several connection points for the weaving of the web, and there must be enough vertical open space for the orbits of the web..
This spider has a life cycle of approximately two years. Females have a pair of spermathecae or seminal receptacles where they store sperm during copulation until egg laying..
Males exude sperm through the epigastric sulcus into a sperm web and transfer it to their terminal palp. Only the correct palp fits the appropriate epigine, thus ensuring the reproductive success of this species.
During copulation, males hug the female's abdomen and insert a palp. Then the male is removed and his palps are again filled with sperm. This process can be repeated few times, since the life expectancy of males is shorter than that of females..
The females reproduce once and die shortly after laying their eggs. The breeding season is at the end of the summer season, and the rearing in juvenile state is achieved the following spring.
This species of spider is carnivorous (insectivorous). It feeds on prey such as insects and other arthropods from terrestrial habitat. In addition, it is common to get another spider such as the Argyrodes, which is small in size and feeds on the remains of prey left by the A. diadematus.
It is interesting how the individuals of this species wrap their prey with a silk thread before consuming them. After killing and wrapping their prey, spiders may or may not consume them immediately.
Thus, the garden spider constitutes a biological regulator or controller of insects, since they feed on them, thus reducing the populations of insects and pests..
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