Poisonous Spiders In Illinois

The majority of spiders living in Illinois are not poisonous. There are, however, two kinds of poisonous spiders found in the area: the brown recluse (Loxosceles reclusa) and the black widow (Latrodectus spp). Their venomous bite is dangerous, and you can come across them virtually anywhere, so it’s crucial to learn how to identify them.

Black Widow

Black Widow Characteristics

The abdomen of a mature female black widow is usually black and shiny with a distinct red hourglass marking on the underside Sometimes there may be a line of red spots down the center of the abdomen. A mature male is smaller than a female and it has several white and red markings on the top and possibly a red or orange hourglass marking on the underside. This poisonous spider usually takes up residence in tree stumps, under rocks, in garages, and in various kinds of structures. This spider is also nocturnal and mostly active at night.

Black Widow Bite Symptoms

A black widow spider is not aggressive by nature, but a female will bite if its web is attacked, usually in defense of her eggs. A black widow spider bite causes immediate and intense pain. Swelling and redness are the first signs around the bite area. Other symptoms are abdominal pain and cramping, but they can also include dizziness, sweating, pain in the chest, or a headache. The bite of a black widow can lead to weakness, paralysis of the legs, and tremors. This venom affects the nervous system, so a bite requires urgent medical attention.

Black Widow Control

The black widow lives in close proximity to man-made objects. Objects such as gardening equipment, lawn furniture, or trash cans that have been outside for a long time should be carefully handled. Eliminate clutter or boxes in your garage or similar areas. It’s also a good idea to seal any cracks and crevices in and around your home to prevent them from coming in.

Brown Recluse

Brown Recluse Characteristics

The length of adult brown recluse spiders ranges from 7–12 mm. Females average 9 mm while males average 8 mm. Their body colors are brown, orange, and tan, and a total of six eyes, arranged in a triad of three pairs, is their main feature. Their legs are long, light brown, and without any markings. These spiders are very “leggy,” and their legs are usually a lot longer in proportion to their body. Sometimes, the brown recluse has a violin-shaped marking on its back, which can be helpful in identifying it, but it should not be used as the sole identifier. The brown recluse is a nocturnal spider that prefers dry, dark, and undisturbed places, such as low-traffic basements and attics.

Brown Recluse Bite Symptoms

The brown recluse is not an aggressive species, but it will bite if it feels trapped. When this spider bites, itchy redness, swelling, pain, and burning pain will occur a few hours after the bite. The bitten area and skin around it will behave purple or dark blue circles. Other symptoms include fever, rash, nausea, vomiting, body aches, or headache. Bites may heal on their own, but you may need treatment if the wound gets worse.

Brown Recluse Control

These spiders can be controlled by eliminating places around the outside of your home that could be good hiding places, such as wood or rock piles, excess leaves, and other debris. Another preventative measure is to seal any cracks and crevices in and outside of your home as much as possible.

Proudly serving the greater Chicagoland area in Illinois and southeast Wisconsin, the professional exterminators at Aerex Pest Control understand the habits of different spiders and use that knowledge when developing a spider control program that is best suited to your home and your particular problem.

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