A Little Bit More
No doubt the fact that all spiders have fangs that are able to deliver venom, has given rise to the widespread belief that all spiders are a serious threat to humans. A spider’s venom is used to paralyze or kill its prey and then juices from its digestive glands are injected into the victim to liquefy its internal organs. Once the digestive enzymes have done their work, the spider simply sucks up the predigested, soup-like material from its prey. I kind of think of it like drinking a thick milkshake!
A few spiders have evolved a violent, pain-producing component of their venom that may deter predation. These specialized spiders often have bright “warning” coloration on their bodies. The crimson hourglass marking on the Black Widow probably serves this purpose although its not always that obvious.
Black Widows favor damp, dark areas such as cellars, under boards, stonewalls, and often old buildings. Outhouses have a particular reputation for attracting this species! Evidently females (males don’t feed or bite) often spin their webs under the toilet seat to catch the numerous flies that are present. It doesn’t take much imagination to understand why this “prime location” seems especially vulnerable! Black Widows are much more common in the southern U.S. but the Northern Widow is found as far north as southern Canada. Bites from Black Widows are not at all common and more than 90% of the people bitten recover. Of course, no one wants to endure a Black Widow bite but there is also no need to be deathly afraid of spiders either – their danger is usually highly overrated.
Activities
Science and Art – Make A Spider
Objectives: Become more familiar with spiders
Materials: Photos of spiders from the library or internet
I’ve illustrated a typical spider for students to color in. They should look in the library or on the internet for orb-weaving spiders and find one they “like”. Spiders come in all kinds of colors and patterns and here is a chance for students to color in the provided illustration to look just like a spider photo/illustration they find. It’s important for them to be sure to get the name of their spider and put it on their rendering so everyone knows which one it is. If the information is available, you may want to color in spiders that are found in your particular area of maybe just a pretty one – you be the judge.
One Step Farther
If you’d like to take this one step farther, you can have your students draw in a web behind the spider illustration. Spiders weave two kinds of threads: one is sticky and one is not. The non-sticky threads are like the spokes that radiate from the center of a wheel and these are the threads the spider used to move about the web. The sticky threads are circular and connect the “spokes” – these are the threads that capture unwary insects. Your students will want to look at webs in photos and drawings but then they should have fun trying to make their own webs for their spider to rest on. Good luck!
Key Concepts
Structures and Functions, Identification
Questions
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Posted by Melissa Ellison on August 16, 2006 at 01:04 AM
Q: I keep finding very large light brown fast moving spiders in my house. They look like small daddy long legs, but they have a pointy thorax, or abdomen. same light brown color on the abdomen, I am afraid if it is poisonous or not, please tell me. There are also black markings on it.
A: Melissa, go to this website and click on the spider icon on the left side of the page. It's a great description of North American spiders along with great description of venomous ones.
Good luck to you!
Posted by Donna Rust on July 10, 2006 at 01:12 PM
Q: I would like to know about the wolf spider and other spiders that are in north dakota and if they are poisnous I would like info. on all of them
A: Try this website: bugguide.net
Click on the spider icon on the left side of the page then scroll through the text. A great site for North American spiders of all kinds. Good luck to you.
Posted by David Ramos on March 10, 2006 at 06:39 AM
Q: I found a brown widow spider in the back yard of my house, I never imagine to see this spiders in P.R. how can I prevent them to came close to the house or geting in.
A: There is always the chance that a spider will get into your home but very few are dangerous. Your Brown Widow, although it is related to the Black Widow, is much less likely to bite than most spiders and injects little venom if(when) it does. I really don't think you have much to worry about - it isn't going to crawl up to you and bite. Sorry I can't more reassuring for you but widow spiders don't bite people often. Gracias for your question.