Spider Types and Identification Guide
Spiders in Your House and Garden
Spider Identification -- Is This Spider Poisonous?
First of all, technically the question is, "Is this spider venomous?" Some spiders have venom that can affect humans, and you need to know if the one you have is one you should be worrying about.
This spider identification guide will help you figure out what you found. Too often, the first thing people do when they find a spider is to start looking for a way to kill it. Believe me, your house is better off with a few spiders around, and in any case you can't kill them all -- one study found that you're never more than about six feet in at least one direction from a spider of some kind. And if you did somehow wipe out all the spiders in your house, you would soon notice swarms of houseflies, fruit flies, mosquitoes, gnats, clothes moths, and assorted other pests flying around your house. Those are all the undesirables that your spider "enemy" eats for you. For free.
So before you reach for the wad of tissue or can of poisonous bug spray, think for a minute. Do you really want the little guy dead? Maybe it would make sense to at least know what it is you're about to kill. Just a thought. This guide will help you tell what kind of spider you're dealing with. Very few spiders are toxic enough to hurt you! And no, they don't bite you when you're sleeping, at least not enough to notice. Why would any spider in its right mind want to get near a coliseum-sized, unpredictable animal like you?
Take a breath and the spider you found with the help of this guide. What's it called? What does it eat? These and many other questions are answered in this article.
The Black Widow and Relatives
The common black widow spider, Latrodectus mactans, is found throughout much of North America. There are related species in the Southwest and into Central America. They are all toxic to humans, but L. mactans is the only one with recorded fatalities.
This spider spins tangled, disorganized webs in dark corners of basements, garages, and wall spaces. I have found black widow nests in rotten stumps and caves as well -- any place sheltered and dark seems to fit the bill. In your house, these spiders keep to themselves and are quite shy, though it does happen that people get bitten by putting their hand in the wrong place without looking.
Typical Black Widow
What To Do If You Find a Black Widow
If you find a large, shiny black spider with long legs, look closely at the underside if you can. L. mactans almost always has a clear red mark underneath the abdomen, usually in the general shape of an hourglass. This mark can vary, though, and just because there's no mark doesn't mean it's not a spider to be concerned about.
Don't worry about trying to capture the spider -- that's when most people get bitten. Simply get your phone and take a picture of the spider and contact a doctor or emergency room technician. They can help you identify your spider.
Orb weavers are the brilliant architects of the spider world. When you happen to notice a beautiful web decorated with shining dew drops, you are looking at the unbelievable work of an orb weaver spider. Spider silk is strong, but perhaps the best way to think of it is in terms of toughness. While silk is technically stronger than steel but not as strong as Kevlar, it is on fact tougher than both. Spider silk's combination of strength and flexibility makes it one of the world's miracles of composition.
And the orb-web weavers take this material and make the most beautiful art with it -- art that is first and foremost designed to be functional. When a prey insect, say a small grasshopper, falls into the web, it is quickly tangled up and attacked by the spider. The web design is specially construction to catch up insects the spider can manage, and let the little ones it doesn't care about slip through.
These amazing spiders often have bizarre shapes. They're found nearly everywhere in the world.
When I was a kid, we used to catch these big guys and keep them for a day or two in a coffee can, feeding them crickets. I imagine the spiders handled the situation pretty well, since in exchange for a little freedom they got an endless supply of delicious prey insects.
Wolf spiders are fierce hunters -- despite their name, they are typically solitary -- and take full advantage of their eight eyes to scope out their surroundings for any moving thing that could be dinner. They have fast-acting venom and a limitless appetite (at least, as I remember, for crickets).
One cool thing about wolf spiders is their habit of carrying their egg sacs attached to their rear end. When the little spiderlings hatch out, they all clamber up to rest on their mother's abdomen.
For identification, it's good to know that two of the wolf spiders eyes are especially large, unlike grass spiders and other similar arachnids. It's also good to know that wolf spiders will bite if you mess with them enough, but their venom is not as severe as bee sting.
The next time you're out in a nature preserve or park, have a close look at the flowers around you. Not the carefully planted tulips and crocuses -- focus on the wildflowers, especially the ones being attended by bees and butterflies. Look very closely, and there's a good chance you'll see one of the many species of crab spiders waiting for its prey.
Crab spiders do not spin webs -- instead they sit motionless in a flower, camouflaged to the point of invisibility, and wait for a butterfly, bee, or fly to come looking for a nectar meal. When the prey insect is close enough, the crab spider strikes. With its strong, curved front legs (the source of its common name), the spider seizes its unfortunate victim, bites it with paralyzing venom, and drains it of its bodily fluids. The crumpled husk of the victim is all that's left -- the crab spider drops it to the ground and withdraws into the flower to wait for another meal.
Crab spiders are often very beautiful, and are almost always well-camouflaged on their perch. They can overpower and consume stinging insects like bees and wasps, as well as large, strong butterflies.
As their name suggests, grass spiders live in grassy areas, including lawns and parkways. They are quite common, and chances are good that the spider you are trying to identify will turn out to be one of the many species of grass spiders in the world.
Grass spiders spin low webs in the grass, and rush out of hiding areas to grab their prey. Their bite is not harmful to humans, though large species will bite defensively. These arachnids control many common pests that would otherwise multiply out of control, so have a heart and let those grass spiders live!
Jumping spiders are so cool. They're little, but tough as nails, and they don't usually spin webs -- instead, they roam around, looking for prey to attack. When it finds prey, a jumping spider will suddenly leap several times its body length to grab and bite its victim. The power of the jumping spider's leg muscles must be amazing, right? Wrong. Spiders don't even have any leg muscles to speak of. It took scientists a long time to figure it out, but here's how they do it:
When a jumping spider decides to jump, it creates a sudden change in it's blood pressure (actually haemolymph pressure, but it's the same thing). It uses a strong muscle in its upper body to suddenly force much of its blood into its legs, which cause them to extend explosively. When all eight legs suddenly snap out straight, the spider shoots into the air. How cool is that?
When you see these little guys on a porch railing or a windowsill, they will quickly notice you too. They have huge eyes and are quick to notice movement around them. They'll quickly swivel their body around to confront you, and often rear back on hind legs to appear threatening. And they're the size of a pea! Pretty great stuff from one of Nature's most appealingly vicious predators.
Jumping Spiders Are Photogenic!
Spider Identification -- Funnel-Web Spiders
There are many, many kinds of funnel web spiders, but a few varieties found in Australia get all the attention. The Sydney funnel web spider and its kin are among the world's most venomous animals, and a bit from one of them send the victim into nightmarish seizures, often leading to death.
However, the funnel-web spiders you are likely to encounter are completely harmless, and eat so many flies, centipedes, and other crawling things that you really should give them a medal, not squash them with a handful of kleenex. They make cool webs that have a characteristic funnel shape in the middle where the spider hides, rushing out to grab any insect that happens to fell into its sticky, spreading net.
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Spider Identification -- Recluse Spiders
Recluse spiders get their name from their habit of hiding in dark corners and under neglected objects during the day. If you have a cluttered garage, there's a good chance there are recluse spiders in there (along with plenty of other varieties of arachnid). Recluse spiders get a lot of attention mainly because one member of the family, the brown recluse, occasionally causes serious bites.
The bite of the brown recluse is not immediately painful, but it sometimes progresses to a skin-eating-type pathology that can cause extensive scarring, and even death, though this outcome is generally due to a "flesh-eating" staph infection that is secondary to the venom. Regardless of the cause, a runaway reaction to brown recluse venom can leave its victim in very bad shape.
Brown recluse spiders come out at night to hunt small arthropods like cockroaches and centipedes, and that's when humans can inadvertently come in contact with them. If you suspect you've been bitten by this spider, call 911 immediately or get yourself to the ER. Time is important when dealing with a brown recluse bite!
Spider Identification -- Lynx Spiders
These beautiful spiders are generally not common, so it you find one consider yourself lucky. They're excellent hunters and seldom spin webs. Lynx spiders spend their days on plants, camouflaged among the greenery, waiting for small insects and other arthropods to ambush. Some are brilliant emerald green; others are shades of brown with finely striated markings that further their camouflage.
The spiny legs that serve as a good identifying characteristic are used as a kind of a basket to catch flying insects. Lynx spiders have excellent vision, with six of their eight eyes arranged in a hexagon -- another good identifying characteristic.
Spider Identification -- The Common House Spider
No, It's NOT a Black Widow!
This cobweb spider is one of the most common arachnids in temperate regions. You almost certainly have them in your house! The coloring is variable but the size, shape, and characteristics of the web will help you know one when you see one. Some of the darker individuals could be taken for the more dangerous black widow spider, but only the black widow has the combination of shiny black body with bright red markings.
Spider Identification -- Fishing Spiders
These amazing arachnids have evolved the ability to prey on fish, which they wait for on the surface of the water until the fish is close enough -- and then they pounce!
Spider Identification -- Daddy Long-Legs Spider
There's always been some confusion about the common name of these spiders -- "daddy long-legs" in the US usually refers to arachnids properly called Harvestmen, while practically everywhere else the name refers to these long-legged spiders. You will most often see them in basement corners, motionless in tangled webs, waiting for prey, Levae them be! They gobble up tons of mosquitoes, flies, and other airborne pests.
The Spider's Web
Spiders typically make webs in out-of-the-way places, and they are marvels of design. They are constructed from silk that is mainly protein, but have several other compounds, including sugars, lipids, ions, and pigments.
The actual process of spinning a web, whether beautifully ordered like an orb-weaver's or tangled like a widow spider's, is accomplished with the use of glands at the tip of the spider's abdomen. These hands are often called "spinnerets," and they are essentially liquid dispensers -- the silk hardens as it hits the air, and so the spider need to constantly "pay out" the hardening silk in a fine thread. It does this with a rising and falling motion of its body, and also with the help of its hind pair of legs (every spider has eight legs).
As if that weren't cool enough, spiders often have different kind of silk glands and different kinds of silk they can produce. For example, some silk is strong and smooth, and is used to attach the web to a tree or railing or other surface. Other silk from the same spider might be sticky and capable of tangling up prey. The two types of silk are necessary for the two kinds of uses. Amazing!