Black Widow Spiders

One of the venomous spiders in the United States, you do not want to have black widow spiders in or around your home. Learn more about these arachnids, including how to control them.

Biology of Black Widow Spiders
The female and male black widow spiders have different appearances. Females are very distinctive, with a red marking in the shape of an hourglass on their shiny black bodies’ round abdomen. This hourglass marking can also be orange-yellow. The female spiders are usually around 1.5 inches in length. Male black widows are typically around half as long as females and lighter in color. Their backs feature pink or red spots. While males usually live just one or two months, female black widows can live for three years. Black widow spiders live in temperature regions worldwide. Within the United States, you are most likely to find them in the West and the South. They enjoy dark, dry shelters, like rodent holes, dense vegetation, outdoor toilets, garages, and barns. Black widows tend to be solitary, except during mating season which is in late spring. Following mating, females engage in sexual cannibalism, meaning they frequently kill then eat the male.

This serves as a protein source to help the young grow. The female spiders will lay egg sacs with 200 to 900 eggs, which hatch in about 30 days. These baby black widows are also cannibalistic so just a few reach adulthood, which takes about three months. These spiders eat insects and other arachnids which are captured in their web. The female will create the web then hang upside from it. When the prey gets trapped in the web, the spider will wrap its prey in silk using its comb feet. It then injects digestive enzymes into the prey, which will liquefy the corpse. The black widow can then suck up the formed fluid.

Why Black Widow Spiders Are Considered Pests
The biggest concern regarding black widow spiders is their bites as this is the most venomous spider within the continent. Compared to a rattlesnake, the bite of a black widow is 15 times the strength. Black widows are also very venomous. The good news is that it is actually rare for a black widow to bite a human. They typically only do so when they are disturbed. Furthermore, despite the myths, it is actually very rare for a bite from a black widow on a human to result in death. Those at a higher risk of death or serious issues include those who are very young or very old as well as those who are sick. Most people who are bitten by a black widow will just notice a pinprick. The pain will then start in a few minutes before quickly spreading throughout the body. There are several species of black widows and the symptoms of the bite will vary based on species. They can include muscle aches, severe pain in the back and abdomen, profuse sweating, nausea, hypertension, and even paralysis of the diaphragm, the last of which can lead to trouble breathing. The pain can last 8 to 12 hours while other symptoms can last days. There is black widow antivenom.

Methods for Controlling Black Widow Spiders
The absolute safest method of getting rid of black widow spiders in your home is to hire a professional to take care of them. This will almost fully eliminate your risk of being bitten during the process. It will also almost guarantee that all of the black widows are found or prevented via control methods like insecticides. There are multiple concentrated insecticides that can be applied in the form of sprays. Liquid residual concentrates get mixed with water and applied by the perimeter of your foundation. You should spray these insecticides around one or two feet up your exterior wall as well as three to ten feet out to create a liquid barrier. Spray by door frames, window frames, vent openings, cable entry points, patio areas, basements, and garages. The best way to ensure you spray all the necessary areas is to hire a professional to do so for you. Insecticide dusts are also very useful, particularly in the case of vent areas, switch plate covers, electric outlets, and other voids. You can apply these with a hand duster. Or you can find aerosol insecticides, most of which are designed to kill black widow spiders on contact. Some will also have residual effects to continue controlling the spiders.

DIY Tips for How to Get Rid of Black Widow Spiders
One of the best ways to get rid of and reduce the risk of having black widow spiders on your property is to reduce the clutter in your home. Black widows and other insects that they feed on like to hide in the clutter in your garage or basement. Outside the home, try to store your firewood on top of a raised structure and at least 20 feet from your home. If you have heavy vegetation by the foundation of your home, you should remove this. Also, take the time to regularly tri any tall grasses. Swap out the bulbs in your outdoor lights for those that do not attract flying insects as this will reduce the food sources for black widows.

While trying to control black widows, always ensure you wear appropriate gear. This includes long pants and long sleeves plus gloves. Use caution when searching for and dealing with black widows. Use similar caution if you take out anything that has been in storage for a long time, as there may be black widows in or on it. You should also try to make sure there are no gaps that allow entry into your home. Repair broken screen and ensure door sweeps are placed correctly. Caulk around windows and doors if necessary. You should also take the time to regularly inspect your home and seal up any cracks or crevices you spot. If you spot spiders in your home, wear gloves when approaching. You can vacuum up the egg sacs, spiders, and webs, then empty the vacuum and throw out the bag, sealing it in a plastic bag.

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