Hi Everybody!!
Tonight we have a different treat: We get to watch a spider eat lunch. First 'the lunch' has to fly into the spider's web. Then the spider wraps the insect in silk that come from the spinnerets. You will discover more about this process below in the info shared from Wikipedia about spiders. This photo series was shot on my rooftop deck in December 2010. (Yes, I forgot to share it for several years!). Anyway, I find spiders to be the best engineers on the planet. I encourage you all to learn more about these little, fascinating guys. Enjoy!

Link to photostudy in G+ Photo Albums:
https://plus.google.com/u/0/photos/117645114459863049265/albums/5676910839091928257

The insect flew into the web. Quickly, the spider ran up to it and began wrapping him in silk while spinning him around. Above you can see the insect when the spider began to wrap him up!

The spider wraps the legs first so the insect can not crawl away

At this point in the wrap, the insect can not attack the spider

The spider begins at the head and wraps down the length of insect

Spider is turning insect round and round

Spider spins the silk from silk glands (see info below)

Now she is wrapping the leg that was sticking out!

They are on the web even though it is difficult to see

The spider spins and spins until you can not see insect, only silk

Spider secures package to the web and walks off for a break

She washes up before lunch

http://en.wikipedia.org/wiki/Spider

Spider

From Wikipedia, the free encyclopedia

For other uses, see Spider (disambiguation).

Spiders Temporal range: Pennsylvanian - Holocene, 319–0Ma PreЄ Є O S D C P T J K Pg N

Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Arachnida
Order:	Araneae Clerck, 1757
Suborders
Mesothelae Mygalomorphae Araneomorphae See table of families
Diversity
109 families, c. 40,000 species

Spiders (order Araneae) are air-breathing arthropods that have eight legs andchelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms.^[1]Spiders are found worldwide on every continent except for Antarctica, and have become established in nearly every habitat with the exception of air and sea colonization. As of 2008, at least 43,678 spider species,^[2] and 109 families have been recorded by taxonomists;^[3] however, there has been confusion within thescientific community as to how all these families should be classified, as evidenced by the over 20 different classifications that have been proposed since 1900.^[4]

Anatomically, spiders differ from other arthropods in that the usual body segmentsare fused into two tagmata, the cephalothorax and abdomen, and joined by a small, cylindrical pedicel. Unlike insects, spiders do not have antennae. In all except the most primitive group, the Mesothelae, spiders have the most centralized nervous systems of all arthropods, as all their ganglia are fused into one mass in the cephalothorax. Unlike most arthropods, spiders have no extensor muscles in their limbs and instead extend them by hydraulic pressure.

Their abdomens bear appendages that have been modified into spinnerets that extrude silk from up to six types of silk glands within their abdomen. Spider websvary widely in size, shape and the amount of sticky thread used. It now appears that the spiral orb web may be one of the earliest forms, and spiders that produce tangled cobwebs are more abundant and diverse than orb-web spiders. Spider-like arachnidswith silk-producing spigots appeared in the Devonian period about386 million years ago, but these animals apparently lacked spinnerets. True spiders have been found in Carboniferous rocks from 318 to 299 million years ago, and are very similar to the most primitive surviving order, the Mesothelae. The main groups of modern spiders, Mygalomorphae and Araneomorphae, first appeared in the Triassic period, before 200 million years ago.

A herbivorous species, Bagheera kiplingi, was described in 2008,^[5] but all other known species are predators, mostly preying on insects and on other spiders, although a few large species also take birds and lizards. Spiders use a wide range of strategies to capture prey: trapping it in sticky webs, lassoing it with sticky bolas, mimicking the prey to avoid detection, or running it down. Most detect prey mainly by sensing vibrations, but the active hunters have acute vision, and hunters of the genusPortia show signs of intelligence in their choice of tactics and ability to develop new ones. Spiders' guts are too narrow to take solids, and they liquidize their food by flooding it with digestive enzymes and grinding it with the bases of their pedipalps, as they do not have true jaws.

Male spiders identify themselves by a variety of complex courtship rituals to avoid being eaten by the females. Males of most species survive a few matings, limited mainly by their short life spans. Females weave silk egg-cases, each of which may contain hundreds of eggs. Females of many species care for their young, for example by carrying them around or by sharing food with them. A minority of species are social, building communal webs that may house anywhere from a few to 50,000 individuals. Social behavior ranges from precarious toleration, as in the widow spiders, to co-operative hunting and food-sharing. Although most spiders live for at most two years,tarantulas and other mygalomorph spiders can live up to 25 years in captivity.

While the venom of a few species is dangerous to humans, scientists are now researching the use of spider venom in medicine and as non-polluting pesticides. Spider silk provides a combination of lightness, strength and elasticity that is superior to that of synthetic materials, and spider silk genes have been inserted into mammals and plants to see if these can be used as silk factories. As a result of their wide range of behaviors, spiders have become common symbols in art and mythology symbolizing various combinations of patience, cruelty and creative powers. An abnormal fear of spiders is called arachnophobia.

Like other arthropods, spiders are coelomates in which the coelom is reduced to small areas round the reproductive and excretory systems. Its place is largely taken by a hemocoel, a cavity that runs most of the length of the body and through which blood flows. The heart is a tube in the upper part of the body, with a few ostia that act as non-return valves allowing blood to enter the heart from the hemocoel but prevent it from leaving before it reaches the front end.^[11] However, in spiders it occupies only the upper part of the abdomen, and blood is discharged into the hemocoel by one artery that opens at the rear end of the abdomen and by branchingarteries that pass through the pedicle and open into several parts of the cephalothorax. Hence spiders have open circulatory systems.^[8] The blood of many spiders that have book lungs contains the respiratory pigment hemocyanin to make oxygen transport more efficient.^[9]

Spiders have developed several different respiratory anatomies, based on book lungs, a tracheal system, or both. Mygalomorph andMesothelae spiders have two pairs of book lungs filled with haemolymph, where openings on the ventral surface of the abdomen allow air to enter and diffuse oxygen. This is also the case for some basal araneomorph spiders like the family Hypochilidae, but the remaining members of this group have just the anterior pair of book lungs intact while the posterior pair of breathing organs are partly or fully modified into tracheae, through which oxygen is diffused into the haemolymph or directly to the tissue and organs.^[8] The trachea system has most likely evolved in small ancestors to help resist desiccation.^[9] The trachea were originally connected to the surroundings through a pair of openings called spiracles, but in the majority of spiders this pair of spiracles has fused into a single one in the middle, and moved backwards close to the spinnerets.^[8] Spiders that have tracheae generally have higher metabolic ratesand better water conservation.^[12] Spiders are ectotherms, so environmental temperatures affect their activity.^[13]

Feeding, digestion and excretion

Cheiracanthium punctorium, displaying fangs

Uniquely among chelicerates, the final sections of spiders' chelicerae are fangs, and the great majority of spiders can use them to inject venom into prey from venom glands in the roots of the chelicerae.^[8] The family Uloboridae has lost its venom glands, and kills its prey with silk instead. Like most arachnids including scorpions,^[9] spiders have a narrow gut that can only cope with liquid food and spiders have two sets of filters to keep solids out.^[8] They use one of two different systems of external digestion. Some pump digestiveenzymes from the midgut into the prey and then suck the liquified tissues of the prey into the gut, eventually leaving behind the empty husk of the prey. Others grind the prey to pulp using the chelicerae and the bases of the pedipalps, while flooding it with enzymes; in these species the chelicerae and the bases of the pedipalps form a preoral cavity that holds the food they are processing.^[8]

The stomach in the cephalothorax acts as a pump that sends the food deeper into the digestive system. The mid gut bears many digestive ceca, compartments with no other exit, that extract nutrients from the food; most are in the abdomen, which is dominated by the digestive system, but a few are found in the cephalothorax.^[8]

Most spiders convert nitrogenous waste products into uric acid, which can be excreted as a dry material. Malphigian tubules ("little tubes") extract these wastes from the blood in the hemocoel and dump them into the cloacal chamber, from which they are expelled through the anus.^[8] Production of uric acid and its removal via Malphigian tubules are a water-conserving feature that has evolved independently in several arthropod lineages that can live far away from water,^[14] for example the tubules of insects and arachnids develop from completely different parts of the embryo.^[9] However a few primitive spiders, the sub-order Mesothelae and infra-orderMygalomorphae, retain the ancestral arthropod nephridia ("little kidneys"),^[8] which use large amounts of water to excrete nitrogenous waste products as ammonia.^[14]

Silk production

Main article: Spider silk

An orb weaver producing silk from its spinnerets

The abdomen has no appendages except those that have been modified to form one to four (usually three) pairs of short, movable spinnerets, which emit silk. Each spinneret has many spigots, each of which is connected to one silk gland. There are at least six types of silk gland, each producing a different type of silk.^[8]

Silk is mainly composed of a protein very similar to that used in insect silk. It is initially a liquid, and hardens not by exposure to air but as a result of being drawn out, which changes the internal structure of the protein.^[23] It is similar in tensile strength to nylonand biological materials such as chitin, collagen and cellulose, but is much more elastic, in other words it can stretch much further before breaking or losing shape.^[8]

Some spiders have a cribellum, a modified spinneret with up to 40,000 spigots, each of which produces a single very fine fiber. The fibers are pulled out by the calamistrum, a comb-like set of bristles on the jointed tip of the cribellum, and combined into a composite woolly thread that is very effective in snagging the bristles of insects. The earliest spiders had cribella, which produced the first silk capable of capturing insects, before spiders developed silk coated with sticky droplets. However most modern groups of spiders have lost the cribellum.^[8]

Tarantulas also have silk glands in their feet.^[24]

Even species that do not build webs to catch prey use silk in several ways: as wrappers for sperm and for fertilized eggs; as a "safety rope"; for nest-building; and as "parachutes" by the young of some species.^[8]