How Many Knees Does a Spider Have?
Female jumping spider, look at those legs! (Photo: Wiki Commons)
Spider Knees in the Know
I had a reader e-mail me for a 10 year old student who wanted to know exactly how many knees a spider has. If you Google the answer you get a web page that is aimed at kids and has the absolutely wrong answer as the first choice. This always infuriates me because they offer an easy, off-the-cuff quick answer that requires absolutely no thought or research. I hate it when people play down to kids and don't do the work required to give an accurate answer. So here goes my attempt.
Wolf Spider Facts and Pictures
Wolf spider (Hogna Lenta) (Photo: Wiki Commons)
Is it Really the Big Bad Wolf?
Have you ever been out with friends, and you see a big hairy spider and someone yells, "wolf spider!"? Now the thing is, there are lots and lots of big brown spiders out there (and "big" is relative to how much you hate spiders too). Wolf spiders are the ones that have a bad reputation because they're big and brown and easy to see, and they have a fierce sounding name so people remember them. If they were called "floofy brown Betsies" or "hairy teddy bears" then most folks would probably just chalk them up to big brown things that happen to saunter through now and again. But no...a biologist long ago thought that wolf spiders hunted like wolves, in packs, and they named the family "Lycosidae." This comes from the Greek "lycosa" meaning wolf. Any time you see an "a" after a Greek name it means the critter is a predator, it eats meat. In the case of spiders, bugs and other small creatures, this particular family name is misleading because wolf spiders the world around are really solitary and don't like hunting in packs. They do pounce on prey but not quite like a wolf does. So let's get down to some real wolf spider facts and pictures.
The Bold Jumping Spider
Bold jumping spider (Photo: Flicker sharing, Tibor Nagy)
Little Spider, Big Attitude
I'll admit it, I'm a big fan of little spiders, especially little wee hairy ones with big attitudes. That's why I wanted to feature the bold jumping spider Phidippus audax (say it with me, fid-DIP-us Ow-dax) for today's post. The name alone says it all, they're small spiders, about the size of those removable pencil erasers on mechanical pencils (6-13 mm), but they've got attitude enough for a mega-spider.
Common House Spiders Found Around Homes
Common house spider (Photo: Karen McDonald)
Common House Spiders Pictorial Guide (Eastern US)
If you're like my friends then the thought of finding a spider in your house causes an immediate visceral response, least of which would be putting on boots and grabbing the Raid can. I know I can't change most people's minds, but I can at least help you identify the spiders you might find and reassure you that they are (for the most part) harmless and quite beneficial. In today's post I'm going to give you a quick guide to the types of spiders commonly found in and around homes in the Eastern United States. These spiders are often referred to as "common house spiders" but the term "house spider" is a bit misleading, and how common they are depends on where you live and the environment in and around your home.
Spider Basics: How Spiders Eat
Jumping spider feeding on a fruit fly (Photo: Jeff Burcher, Flicker Sharing).
Slurping Up The Goodness
I haven't done a good spider post in a while, and since this is the Infinite Spider Blog I do feel this need to keep up. I've written about spider feet, how spider legs work, spider eyes, orange and black spiders, fishing spiders, and brown spiders but what I haven't covered is how spiders eat. There are two answers to this question, and the answer depends on how the spider gets it food.
What is That Big Orange Spider?
Marbled orb weaver (Photo: Ben Jackson, Flicker Sharing).
Identifying The Most Common Orange and Black Spider
Fall, in the Eastern US, is a time for my favorite spiders to start showing themselves. I admit a soft spot for orange spiders, because they always signal fall and Halloween to me, a changing of the seasons if you will. So what is the most common orange and black spider you see right now? Most likely you are beginning to notice Araneus marmoreus, or the marbled orb weaver. It's a great name for a rather large and brightly colored spider.
Daddy Long-Legs Facts and Fiction
Daddy long legs or harvestman (Photo: Wiki Commons)
An Introduction to Daddy Long Legs
As a kid I remember shrieking and being chased around the playground as little boys ran after the girls and tossed daddy long-legs us. Of course we all just knew they were man-eating spiders and we'd be bitten. Invariably though, the poor "spider" would lose a leg or two, fall quite short, and we'd race off to safety. Since then I've come to quite like daddy long legs and the members of their family, mostly because I think they get a pretty bad rap.
Daddy long legs in the UK (Photo: Wiki Commons)
Daddy long legs are arthropods (which means "joint foot"), but they are not spiders. Even though superficially they look like spiders, and move like spiders, they aren't. Their family tree gets moved around a lot, because no one is quite sure where they belong, but most think they're more closely related to mites or scorpions (sans sting or venom). Sometimes they are called granddaddy long-legs, harvest spiders, or harvestmen. Daddy long-legs are found on every continent except Antarctica, and it's thought that there are nearly 6,500 species, 46 families, and 4 suborders world wide! That's a lot of species for a group that is commonly misidentified.
Fishing Spiders 101
Six spotted fishing spider (Photo: Patrick Randall, Flicker Photo Sharing)
"Eek...They're Big Enough to Saddle Up and Ride!"
Have you ever been near the water's edge and seen very large spiders that are hanging out in or on the water? If you're in the Eastern United States near fresh water or brackish water, then you've most likely met the common fishing spider also called dock spiders or wharf spiders. At our rowing boat house we call them launch spiders too. In part this is because they like to ride in our launch boat and if you hit high speeds in that launch boat they tend to "launch" themselves at you when they lose their footing (which our fearless coaches can attest to!). Fortunately, fishing spiders are very harmless and quite skittish despite their size (ranging from 1-3").
Fishing spiders belong to the genus Dolomedes (dole-o-me-dees) in the family Pisauridae (fizz-our-i-day), and compared to other tiny spiders they look big enough to carry off small children (when actually they eat small bugs, tadpoles, and other invertebrates). There are 100+ species of Dolomedes world wide but 8 that are common in the US. These include (using my common names and Latin names):
Black And Yellow Spiders: What Type of Spider Is That?
Black and yellow garden spider (Photo: Wiki Commons)
Identifying Black and Yellow Spiders
Spiders come in all shapes and colors and sizes. It is the ones with the bright colors and large sizes that both frighten and fascinate us. In a previous post I talked about identifying brown spiders, so I thought it only fitting that I do a post on black and yellow spiders, which are commonly found in the Eastern United States.
First, a disclaimer, I'm not a spider expert, but I am a naturalist who has had years of experience in the field. This is by no means a complete picture of all of the yellow and black spiders out there, just a snapshot of the most common ones. None of these spiders are harmful to people, but they can and will bite when frightened, like all animals or insects. However, their presence and job as insect eaters far outweighs the possibility of being bitten by these harmless spiders.
The black and yellow spiders that you are most likely see are (in alphabetical order):
What are the Differences in Spider Feet?
The leg of a pink toed tarantula. (Photo: Wiki Commons).
Spider Feet For Different Purposes
For Valentine's Day my friends at the Smithsonian featured a cute little spider called the pink toed tarantula. This got me thinking about spider feet. They don't really have toes like you and I do, (though the idea of spider tube socks with toes is funny) but they do have special modifications that help them get about. The feet of spiders can be lumped into two general categories based on how the spiders make their living. There are web building spiders and wandering spiders.
The demands of weaving a web and walking a continual tightrope, are very different from those of a spider that wanders, runs, and leaps on prey ( If you haven't read my post on spider legs you should check it out too).
The First thing to know about spider toes is that all spiders have hairy feet (which is why so many people find them creepy), but it's the arrangement and function of these hairs that varies.
Spider Legs: Hydraulics in Action
Spiders are amazing works of engineering (Photo: Karen McDonald).
How Spider Legs Work
Let's face it, spiders are considered creepy by a large majority of people around the world. Yet when you ask them, most folks can't really name what it is about spiders that freaks them out so much. Usually explanations start with beady eyes, fangs, bites, or wrapping up their prey. Spider movement is also at the top of the list. They scuttle and scurry around at night (especially when you turn on the lights and they scamper off), jump, and generally run in a "creepy" way. But what makes their movement really foreign and creepy to us? The answer lies in two key elements of their anatomy, their skeleton and muscles.
How Many Eyes Does A Spider Have to Help It See?
Jumping Spider eye close-up (Photo: Thomas Shahan Flicker sharing).
Spider Eye Counting
The short answer, it depends. For those of you who don't like spiders, I can see that getting up close and personal enough to count their eyes might be a bit daunting, that's why I'm writing this blog post. Spiders are amazing, and diverse, as well as being very beneficial for you and local ecosystems. To understand their eyes you have to understand their lifestyle. Here's a quick primer:
Identification Tips for Brown Spiders of the Eastern US
A wolf spider carrying its egg sac. (Photo: Wiki commons)
Knowing What is and is Not A Brown Recluse or Wolf Spider
I'm often amazed at the number of times I've been outdoors with someone and when we see a brown spider immediately someone says, "Look, there's a wolf spider." I have to admit, I hate identifying "little brown jobs" or LBJs (a term we use commonly for brown sparrows when birding) because it's hard to find the fine distinctions between species, especially when the creatures are moving or you're just skeezed out by the hairy eight legged creature crawling across your floor. However, it is important to understand that not all brown spiders are wolf spiders.
There are many different types of brown spiders and this blog post will help you begin to tell the difference between them. I'm going to write mostly about the spiders common to Eastern and mid-western North America, because this is my home range, but there is some overlap with western species.
A great starting place to learn spider ID and to become familiar with their body parts, names, and the eye placement of spiders is on the website "Spider Identification Guide." I am particularly fond of their great graphic on the 25 different eye patterns you can find on spiders (I wonder if they make this in poster form?). Begin with the basics of spider anatomy on their website if you need a refresher. They also have a great guide for finding spiders by region and color. Check out their page on "Brown Spiders" for a quick browse of the diversity out there.
Check Your Firewood Before Bringing It Inside
Common North American Black Widow Spider, Female (L. Mactans)
Every year around this time I'm reminded that it's important to check firewood carefully before it comes inside. We keep our wood under a tarp outside near the house. Many different invertebrates, and even salamanders and other reptiles, will overwinter in a wood pile. Be sure to shake off the wood you bring inside because the warm interior of your house is a perfect place to "wake-up" and start crawling around if you're an insect!