Nephila pilipes

Nephila pilipes, older females without stripes

Nephila pilipes is a silk spider, whose distribution extends from China via the Philippines to Australia. A subspecies N. p. malagassa comes also proposes to Madagascar. The type is one of the largest silk spinning and is also used as farm animals. In particular, the networks are used as fishing nets and their flesh as food.

Features

This spider is one of the largest not for the tarantulas belonging spider species in the world. The females are probably three to five inches long. The documented by Michael H. Robinson and Barbara Robinson body length of an adult female was 4.21 inches, the cephalothorax length was 1.41 cm. When one leg of the first pair of legs, the length of 8.6 inches and a leg of the fourth pair of legs was determined a length of 7.05 inches. The males are comparatively tiny and probably average 0.5 inches long. The largest documented by Michael H. Robinson and Barbara Robinson body length of males was 0.76 centimeters.

Females have an elongated abdomen ( opisthosoma ), which is colored very differently depending on their age and size. This is probably also the reason why that many synonyms exist for this spider. The opisthosoma is at a younger age black to olive color, depending on size and carries two or four yellow longitudinal stripes. First, the outer two longitudinal stripes form back and with increasing age, the inner two longitudinal stripes. With increasing age and size of the abdomen is almost uniformly gray brown to olive color; only in the front half near the front body ( prosoma ), the opisthosoma has a black crossbar, often where the remains of the yellow longitudinal stripes may appear as fine yellow stripes. The regressing these strips can go at different speeds depending on the individual. Thus one finds younger animals that have only two yellow longitudinal stripes and older who still have all four longitudinal stripes. The bottom has several yellow dots, only the region of the spinnerets is colored red.

The prosoma is bright white, silver to beige. The buttons are striking orange to red colored, only the metatarsus is two-tone yellow and black of Tarsus dyed black. The color of the legs varies by locality and age: In the very elongated legs, the coxa and the trochanter yellow, depending on the locality colored black. The femur is black with one yellow spot on the bottom at the beginning and end. The patellae are colored black with a narrow yellow spot on the bottom of the transition to the tibia. The tibia is also dyed black and has a yellow spot on the bottom of the transition to the metatarsus. Metatarsals and tarsi uniformly black. There are specimens with reddish legs with black knee where these yellow parts are missing. The sternum is black.

Behavior

Reproduction

In the power of the female very often occur several males simultaneously attempting to mate with the females. The males interact with each other here, where they fight in is too close to the legs and bite. Only the victorious male mates with the female. To this end, the male climbs onto the underside of the abdomen of the female and pumping his seeds from his bulbs into the genital opening of the female. This process takes a relatively long time. Pairing times out of ten to seventy minutes, measured. It has never been observed that the female eats the male after mating. The male leaves the female after mating.

For oviposition, the female builds a about 5 centimeters long cocoon. Measurements were made on average between 2000 and 3000 eggs with an average weight of approximately 1.2 grams.

Network construction

The female spider is building networks with 0.6 to 1.0 meters in diameter. Male spiders do not build networks, but living in the network of a female, feeding on insects that are too small for the female, and of the remains of the spoils of the female.

Protection against overheating

The spider protects itself like the Golden Silk Spider from overheating. To this end, she stretches against the abdomen of the sun, which increases the angle of the sun rays. Likewise, liquid is processed in the chelicerae, which also provides cooling.

Enemies and parasites

In the networks often are up to forty thief spiders of the genus Argyrodes. These are small spiders that steal a share of the spoils of the silk spider.

It was investigated why the spiders are eaten in nature do not birds; under laboratory conditions, many birds ate the spiders. However, the laboratory birds tried to eat a spider in the web of Nephila only once. The reason lies in the sticky webs of silk spiders, which also serve as protection against birds. Once a bird has ever flown in a network, a large net that hangs on the body of the bird and the bird takes a long time until he has freed his plumage it. Birds that have once had this experience, shy silk spider webs in the future.

The spider as farm animals

The females of Nephila pilipes be used in the South Pacific as net makers. There are bamboo pipes set up as a framework and the spider makes its web in this context, which is later used for fishing.

The natives eat the female spiders as a protein supplement raw or roasted. The court can also be mixed with raw potatoes or salad.

Synonyms

Since this spider has a different body coloration depending on the location, size and age, it has been repeatedly recognized taxonomically. There are according to Platnick before several synonyms. The most common synonym is Nephila maculata.