Most spiders are small, inconspicuous arthropods, which are harmless to humans. There are only four species found in the United States whose bites cause serious reactions in humans and only two consist of the nearly species of spiders in Galveston County. Quick Facts Some Differences Between Spiders and Insects. All spiders can produce silk throughout their lifetime Only a few insects can produce silk and then only during certain periods of their lifetime.
Number of Body Segments:. Number of Legs:. Basic Spider Biology. Spiders are arachnids, not insects; however both belong to the largest group of animals on earth—the arthropods. These are animals with hard external skeletons and jointed limbs. Simply put, spiders have two main body parts a cephalothorax, which is the fused head and thorax, and an abdomen on which the tip has a group of small spinnerets that produce silk whereas insects have three body parts head, thorax and abdomen.
Spiders have eight walking legs and insects have six. Spiders have a piercing jaw and fangs the jaw-like structures are called chelicerae, each of which ends in a hollow fang through which venom can be ejected and insects simply chew. Spiders can't fly, but many insects can.
Spiders come in unusual body shapes and colors, which are helpful to deceive and ambush prey, as well as to attract mates. The spider size is somewhat limited as their respiratory systems become less efficient as their size increases.
Yet there are spiders that are quite tiny and found in hidden areas such as damp, cool forest leaf litter and moss. This is because their small bodies will lose water quickly in dryer habitats. On the other hand, some spiders grow so large that their legs can span a dinner plate. These spiders usually take more than a decade to reach full maturity. Spiders lay their eggs in a silken, egg-shaped sac.
The egg sac can be hidden in a web, attached to a surface, or carried by several of the female species wolf, cellar and nursery web spiders. Spiders may produce several egg sacs, each containing up to several hundred eggs.
Young spiders, known as spiderlings, emerge from the egg sac and disperse. Many climb to the top of a nearby object, produce long filaments of silk known as gossamer and are carried by the wind.
This method of dispersal is known as ballooning. Young spiders spiderlings resemble adults except for their smaller size and coloration. A spider grows by shedding its skin between four to twelve times before maturity. Adult male spiders are smaller than females, sometimes dramatically so. Males are identified by an enlarged pair of palps mouthparts , which have been compared to miniature boxing gloves or a fifth pair of legs.
These palps are used to transfer sperm. Male spiders are often found in homes as they tend to wander during the mating season in search of females or during the early fall when cooler outdoor temperatures force them to find shelter. Though some species of spiders widows and some wolf spiders may live for a few years, most only survive for a season. However, tarantulas will often survive a decade or more. Another thing that sets spiders apart from all but a few insects is their ability to spin silk.
All spiders produce silk, which is secreted as a liquid through their spinnerets and hardens on air contact. Spiders use silk for a variety of purposes, such as making egg sacs, capturing and holding prey, making shelters or retreats and transferring sperm during mating.
Send it in a rigid container, preferably in alcohol. The spider you're trying to identify does not have to be one of the few species you've already heard of! Why, oh why, do people think any unfamiliar spider must be "new to the area" and presumed dangerous? Outdoor spiders are not drawn to indoor habitats where they can't survive. Indoor spiders are different species, called house spiders.
If you put a house spider out in the yard, you aren't doing it any favor; it probably won't survive there. Spiders in sinks and bathtubs come down the walls, attracted by water. They cannot come up through the drains!
No, those big, hairy, fast-moving spiders you see indoors are not wolf spiders well, hardly ever. Most likely male house spiders. House spiders pose no significant danger to you, your children or your pets. Especially compared to your fellow humans! The well-known structure and behavior of solpugids sometimes called "camel spiders" makes their alleged human-flesh consumption absurd. Tall tales alleging that "camel spiders" which aren't spiders have super-powers and do horrible things to men and camels are all phoney.
Urban legend alleging that hatching tarantula eggs made a potted cactus plant explode, has no basis in fact or tarantula biology. A internet hoax claimed a deadly exotic spider lurks under toilet seats in planes and around airports; everything in the story is fake.
A media blitz about hordes of giant, rare, venomous spiders under Windsor Castle England derived from a common, harmless cave spider. A worldwide news report claimed "swarms" of deadly spiders suddenly invaded an Indian village.
The scare started with 2 snake bites. The recent idea that spiders "hold their breaths" to escape pesticide is not supported by research. The lung slits can't close completely. Do you swallow live spiders in your sleep? There's no evidence of it — no specimens, no eyewitness accounts, nothing!
If spiders drink from mouths or eyes of sleeping humans, there is no physical or eyewitness evidence of it. Do female black widows always kill and eat their mates? In most species that has never been seen in the wild, just in cages. In a 20th century legend, spider eggs hatched inside a bouffant hair-do. Not consistent with known spider behavior. Contrary to urban legend, spiders are not able to lay their eggs inside the skins of ripe banana fruit.
Very widespread and persistent legends of spider eggs hatching under human skin, contradict all we know of spider behavior and abilities. Various natural plant products are alleged to repel spiders. There is no evidence that spiders can even smell them. About 20 lesser-known spider myths, featuring jumping tarantulas, poisonous spider urine, ten-legged spiders, and more. Nearly all have other causes. House spiders could not survive without insect prey.
Therefore, your house contains insects even if you see only spiders. Real spider fang punctures in human skin are hardly ever visible to the naked eye. If you have two visible marks, that doesn't mean a spider bite! Practically all spiders have venom; none that I know of are poisonous to eat. Theraphosid "tarantula" spiders are big and spectacular but not particularly dangerous. Very few pose even a mild bite hazard. There is no spider on earth whose bite is likely to cause death in humans, especially with medical treatment.
The most notorious "deadly" spiders of Australia and Brazil are not as toxic as their reputation; very few deaths have ever been recorded. British media hype about "killer" false widow spiders is irresponsible and wildly exaggerated; the rare bites are mostly just painful. Brown recluse spider bites occur only in 15 states.
Hundreds reported from other states and Canada are all false reports. Contrary to what you've heard, you cannot recognize a "brown recluse" spider by a violin shape.
Numerous other spiders have one too! A chevron pattern, boxing-glove palps or a funnel web do not mean it's a hobo spider; you need a microscope to determine that. Hobo spiders are neither aggressive nor are they true house spiders; the inflammatory name "agressive house spider" is a reject. Inadequate studies claimed that wolf spiders, "yellow" sac spiders, woodlouse spiders and white-tailed spiders were dangerous.
They aren't! Few if any physicians can correctly ID spiders from bite symptoms alone. Spiders caught biting should be ID'd by arachnologists. Several studies show that only in rare cases do spider fangs carry lesion-causing microorganisms. Antibiotics help only if it's not a bite. Spider bite cases resulting in amputation are sometimes reported, but no such case has confirmation of actual spider involvement.
Spiders seldom need controlling and pesticides are not the best way to do so. Sticky traps or better yet, physical exclusion work best. Harmful spiders? How spiders eat and hunt Most species are carnivorous, either trapping flies and other insects in their webs, or hunting them down. Threats The greatest threat to spiders is habitat loss, although some spider species are also threatened by the pet trade.
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