Unless you're one of the good guys (we're talking about the extra sexy Black Widow of Marvel Comics fame [there's just something kinda nice about tight black body suits]), the black widow (genus Latrodectus) is one of the most feared spiders in North America. The image of that red hourglass on glossy black has been ingrained in our brains since childhood. For many people (myself included), the mere thought of black widows brings on an inextricable bout of terror. And yeah, I know, "spiders are our friends." BS. The day a black widow spider brings me a nice bouquet of flowers instead of goosebumps is the day I call them friend.
Anyway, time to be rational. Yeah, there are widow spiders all over the U.S. and Canada. Actually, there are five different kinds found north of Mexico: the brown widow, southern black widow, northern black widow, western black widow, and red widow. While they all come equipped with a lovely neurotoxic venom, you'll be pleased to know that they are fairly non-aggressive and pretty much only bite if they feel threatened. Also, the number of people that actually die from a black widow bite is extremely small. On average, it's less than three per year. Not surprisingly, the people at highest risk are children, the elderly, and those already in poor health. That being said, you should still be quite wary of them. A black widow spider bite can be bad news, even if you're in good health. Check the right side of this page for bite symptoms. If you've been bitten by one or even suspect that you may have been, do yourself a favor and get to the hospital. If you simply want to take the risk of getting rid of black widow spiders before you get bit, then read on. Remember to always be careful, wear gloves and boots, and tuck your jeans into your socks. It looks cool. I promise.
Control Methods for Black Widows
Avoid black widows through exclusion. Do whatever you can to keep black widows from getting into your home in the first place. Walk around the outside of your house with a caulking gun and a tube of sealant. Fill any little holes that you might see around wires, cables, faucets, outlets, etc. Fill cracks in the foundation. Look at your window screens and patch any holes. Apply weather stripping to all windows and doors. If you don't have them already, install door sweeps. These spiders are pretty small and can get through openings that you might think aren't worth messing with.
Make the outside of your house and your yard inhospitable to black widow spiders. The first thing you will want to do is to clear away any and all vegetation that might be up close and personal with your house, especially ivy (read: how to get rid of ivy). That stuff is a haven for spiders. Cut back shrubs, plants, and decorative grasses. Get rid of rock piles, and move any wood piles as far away from your house as possible. Don't use any outdoor lighting. Outdoor lighting attracts bugs galore. Black widows eat bugs. Do the math. If you must use outdoor lights, go with yellow to minimize the number of insects you lure in.
Indoor black widow control measures. Don't leave things lying around. Pick up clothes, blankets, magazines, newspapers, and anything else that a black widow might be able to use for a hiding place. Move your bed a few inches away from the wall and don't allow any bedding to hang on the floor. Rearrange furniture on a regular basis so you can find any widows that might have set up shop. Don't store firewood indoors. Black widows like moisture, so set up a few dehumidifiers. If you find other spiders (with the exception of brown recluse spiders [read: how to get rid of brown recluse]), leave them alone. Not only will some spiders eat black widows, they also add competition for other bugs so the widows don't eat quite as well.
Go on a search and destroy mission. One of the best ways to kill a black widow is simply to squish it. At night (they're nocturnal), go around with a flashlight and a stick and let the fun begin. Inside or out, search everywhere. If you see one, put your stick to use. Just make sure you squish it good and proper. If you miss and the widow hits the floor or ground, stomp it good and leave no doubt. Keep in mind that black widows, females especially, are never far from a hiding place. If you screw up, they will go directly into hiding and you might not get another chance.
Put your vacuum cleaner to use. If your vacuum cleaner has a hose attachment, you have a pretty good spider wranglin' tool. Check your house over from top to bottom. Look in closets and cupboards, behind furniture, and search anywhere else you think a black widow could be hiding. If you've got the guts, spend some time in the attic, the basement, and the garage. These are great places for black widows. The vacuum is nice because it can sometimes pull the black widows from hidey-holes that might have protected them from you. Vacuum up any egg sacs you see too. When you're done, remove the vacuum bag, put it in a tight-closing plastic sack, and put it outside in the trash immediately.
Kill Black Widows
Due to their extreme overabundance (even one is too many), there are a number of pesticides on the market today that work well for killing black widow spiders. There are several different application methods too. There are treatments for outside the home, sprays for direct contact, dusts, and liquid spot treatments. For best results, I recommend using several, if not all, of these.
For outside the home. Before filling foundation cracks and holes, apply something like Delta Dust Insecticide (active ingredient: deltamethrin) or Drione Dust (active ingredients: pyrethrins, piperonyl butoxide, and amorphous silica gel) to help avoid future invasions. For spraying trees, plants, and lawn, Spectracide Triazicide Insect Killer. Demand CS (active ingredient: lambda-cyhalothrin) is a good spray for outdoor foundations.
Sprays for direct contact. If you've got one of the little nasties in your sights, hit 'em with a non-residual aerosol spray like 565 Plus XLO (active ingredient: pyrethrins) or CB-80 Extra Aerosol (also pyrethrins). They're both safe to use and have a quick knockdown and kill time.
Dusts. These work quite well for out-of-the-way places like basements, attics, wall voids, and crawl spaces. Look for products like Drione Dust and Delta Dust Insecticide (both mentioned above). EcoExempt D from the EcoSmart Company is a plant-based (hexa-hydroxyl) insecticidal dust.
Liquid spot treatments. These are generally available in powder form and are mixed with water to be used as a residual spray. Demon WP Insecticide, Cynoff EC, and Cynoff WP (active ingredient: cypermethrin) all come highly recommended. Demand CS (see above) can also be used indoors as a spot treatment.