Iowa is home to many different types of spiders of all different sizes, shapes and colors. Some spiders can be very poisonous and could require medical attention after a bite! Unlike insects, spiders have eight legs and are in the arachnid family, along with mites and ticks. Spiders can live in almost any habitat. Below are some of the most common spiders in our area.
Female black widows are easily identified by the black body and reddish hourglass shape of the abdomen. Males are lighter in color, with a median row of red spots with white lines radiating out to the sides. Immature black widows are usually orange and white, turning black as they mature, with 1 or 2 reddish markings on the abdomen. Outdoors, black widows are commonly found in protected areas such as under firewood, decks, in hollow stumps, rodent burrows, etc. Black Widows are also frequently found inside barns, sheds, henhouses, meter boxes, barrels, etc. When indoors, they can be found in seldom used areas of basements, crawlspaces and garages. The black widow is a very poisonous spider. If bitten, medical attention should be sought immediately. The venom is a neurotoxin and an antitoxin is available.
BROWN RECLUSE SPIDER
The brown recluse varies from light tan to dark brown in color, with a violin/fiddle-shaped dark brown mark starting at the front of the spider with the neck of the violin pointing towards the rear. The recluse name comes from their reclusive habits. They prefer to live in undisturbed, seldom-used areas such as boxes, underneath tables and chairs, along baseboards, in closets, attics, crawlspaces and basements. When outside, they live around rocks, logs, woodpiles, in utility boxes, exterior rodent bait stations and debris. If disturbed, the spider usually tries to run for cover instead of biting. Bites commonly occur when putting on seldom-used clothing and shoes, cleaning out closets or storage areas or rolling over on one while in bed. Their bite is not usually felt immediately, but pain is usually felt within 6–8 hours of being bitten. An ulcer usually forms where the bite occurred and can result in severe scarring. No antitoxin is available for brown recluse bite victims.
The Cellar Spider is a very common spider, typically found in basements, cellars, crawl spaces, and other dark, damp places. Usually pale yellow to light brown or gray in color, cellar spiders have very long, thin legs. They hang upside down from their webs, which they built in the corners of garages, sheds, barns, on eaves, window frames, ceilings, closets, etc. The cellar spider is harmless.
DARING JUMPING SPIDER
These furry little spiders average in length of 1/8” and can be as large as ¾”. Their colors vary from yellow, blue, green, red to almost every color in the spectrum. They are great hunters, and with short stocky legs, they have the ability to jump very quickly and to impressive lengths.
FUNNEL WEB SPIDER
The funnel web spider is brown in color with dark longitudinal stripes running down the back. Their legs may also have banded markings. This spider’s web is often seen on mornings after a heavy dew. They build their webs in bushes, on grass, and occasionally in siding or under eaves. The web is a horizontal sheet-like structure with a small, funnel-like tube in the center or off to the side. Funnel web spiders primarily feed on insects and are harmless to humans.
Black and yellow garden spiders are found throughout the United States and Canada. Female garden spiders are much brighter in color and up to four times larger than the males. They can produce a complex web with a distinctive zig-zag pattern in the center. The garden spider diet consists of insects like flies, bees and other flying prey. Garden spiders produce venom but are not harmful to humans.
Jumping spiders can be black, brown or gray in color with white, gray, yellow, red, blue or green markings. Their furry, compact body has relatively short legs. Despite the short legs, they have the ability to jump up to 20 times their body length. Unlike most spiders, the jumping spider is active during the day. They can be found indoors underneath furniture, in drapery, on bookshelves, around door or window molding, etc. Outdoors, jumping spiders can be found under loose bark, between leaves, under stones, on decks, etc.
ORB WEAVER SPIDER
Orb Weaver spiders come in a variety of shapes, colors and sizes. They generally have a rounded abdomen and orange, brown or black coloring. Body size ranges from 6mm for males and 10–20mm for females. They’re commonly found on corners of homes, eves, under decks and protective porches. Orb spiders often spin a new web every night and can help lower a mosquito population.
Wolf Spiders are very common in Iowa. These spiders have long legs and range in color from gray, brown, black and tan with dark brown or black stripes. Wolf spiders don’t spin webs, instead they hunt down their prey. Females are larger than males and will vary in size from 1/4th” to 1,” not counting their legs. A Wolf Spider’s diet consists of all ground dwelling insects, including other spiders. If provoked, wolf spiders will bite but are harmless to humans. Female Wolf spiders carry her egg sack at the bottom of her abdomen and later carry the babies on her back.