S & W Pest Management Inc : Pest of the Month

Pest of the Month:

Many people are afraid of spiders. This fear is partly due to myths and to the notoriety of harmful species such as the brown recluse spider and the black widow spider . Several species of sac spiders are suspected of being responsible for most spider bites, especially ones occurring indoors. However, the vast majority of spiders are harmless to humans.

What spiders are common in and around homes?

What spiders commonly bite humans?

How do I prevent an infestation?

Who do I call if I suspect an infestation?

What spiders are common in and around homes?

Black Widow Spiders

The black widow spider is widely feared because of its bite. The black widow spider has a potent neurotoxic venom and is considered the most venomous spider in North America.The bites cause severe pain that may take several days to subside. However, the female injects such a small dose of venom that it rarely causes death. Reports indicate human mortality at well less than 1% from black widow spider bites. Bites most frequently occur when people are picking up an item under which the spider is hiding or putting on a shoe the spider has crawled into.

Adult males are harmless and are about half the female’s size, with smaller bodies and longer legs. Newly hatched spiderlings are predominately white or yellowish-white, gradually acquiring more black and varying amounts of red and white with each molt. Juveniles of both sexes resemble the male and are harmless. The characteristic red markings on the underside of the female's abdomen often connect to form an hourglass shape, but this does not always occur. Some specimens may have red-to-orange and ever yellow apearring on the top of the abdomen.

Black widow spiders spin their webs near ground level. They often build their webs in protected areas, such as in boxes and in firewood and often gain entry into a structure when firewood is carried into a building. They are also found under eaves, in boxes, and other areas where they are undisturbed.

Brown Recluse Spiders

The brown recluse spider is often called the "violin" spider or "fiddleback" spider because of the distinctive fiddle-shaped marking on top of its back. Brown recluse spiders are nocturnal and eat other bugs like cockroaches and crickets. Male brown recluse spiders wander farther than females and will crawl into shoes or other clothing.

Brown recluse spiders often live outdoors in debris and wood piles. They can be found indoors in storage areas and dark recesses.

Like the black widow spider, the brown recluse spider bites in defense and does not seek out to bite people. The brown recluse spider bite is painful and can produce an open, ulcerating sore.

Parson Spiders

The parson spider is a nuisance in homes and is generally nontoxic; although some people may experience allergic reactions to the bites. The front segment of the body tends to be a chestnut color, while the abdomen is grayish with a distinctive white or pink pattern along its middle. The body is covered with fine hairs, giving a velvety appearance. The parson spider is usually found outdoors under rocks or in piles of brush or firewood. This spider does not spin a web, but wanders on the ground in search of prey.

Indoors, this spider wanders about at night and conceals itself beneath objects or in clothing during the day. Most bites from this spider occur at night or when it is trapped in clothing. While the parson spider is not considered poisonous, bite symptoms are variable in severity. Some people may experience localized allergic swelling and itching in addition to initial pain. A few persons may experience excessive swelling, nervousness, nausea, sweating and elevated temperatures from the bites.

Wolf Spiders

Wolf spiders are the largest spiders found in Nebraska. Their bodies are covered with short hairs in shades of brown, black, gray, white, yellow, or green. They do not make webs or web snares, but instead hunt for prey. Some of these spiders shelter under leaves or debris while others construct retreats in shallow tunnels or dig deep burrows.

Wolf spiders often alarm homeowners because they are large and move very quickly. We see most of these spiders in the fall when concerned homeowners find them in their garages or in and around the house. Wolf spiders are not "house spiders" and will likely die in the home. They are considered accidental invaders. These beneficial spiders can be removed and placed back outdoors where they belong.

As with any spider, do not pick them up with your bare hands. Place a cup over the spider, then gently slide a piece of paper or cardboard under the cup. You can then carry the cup with the spider outdoors and release it away from the home.

Woodlouse Hunter

This medium-sized spider has three pair of legs directed forward and one pair back. It has 6 eyes, closely grouped together. People are often concerned about this spider because it has two enormous, sinister-looking fangs. Its long jaws are used to hunt woodlice, including pillbugs and sowbugs.

The woodlouse hunter has distinctive coloration: head and thorax of the woodlouse hunter is brown, legs are reddish-orange, and abdomen is pinkish-tan. The spiders rest during the day under stones, bark or other objects in a silken cell in which the female spider lays her eggs. It is an active hunting spider, feeding at night. It is often found around buildings. It is considered an accidental invader in the home.

Yellow Garden Spiders

These spiders, sometimes called banana spiders, are the largest web-spinning spiders in Nebraska. Full-grown females of the common Nebraska species exceed one inch in body length; males are usually much smaller. These spiders make beautiful, large "orb" webs in gardens and between tall grasses and weeds.

One common type of this spider, the black and yellow garden spider, has silver hairs on the back of its forward body section. The large abdomen is marked in black and bright yellow.

Another common species, the banded garden spider, is like the black and yellow garden spider. It has lives in the same locations, builds the same type of web, and is a large spider. But the pattern on its abdomen is different. The abdomen is marked with alternating thin, broken, horizontal silver and yellow lines on a black background.

Garden spiders attract a lot of attention because of their size, bright colors and large webs. They also build their webs in open areas near humans. Some people are uncomfortable working around such large spiders, but many gardeners welcome these attractive insect-eaters.

Yellow Sac Spiders

Some members of this group of spiders are quite common in homes. These spiders are light or dark-colored and have a darker coloration on the cephalic (head) region. The body is covered with short hairs which give it a silky appearance.

The nighttime feeding behavior of sac spiders is similar to that of the parson spider. These spiders do not capture prey in webs, but actively hunt their prey at night. During the day, they hide in tubular silken capsules that they construct which gives them their common name. You may be able to find silken capsules on walls, ceiling, draperies and other locations. Bites from these spiders may result in localized allergic reactions in some individuals.

The venom of sac spiders contains a cytotoxin—which means it kills cells—like the venom of a brown recluse. Unlike brown recluse bites which can take 2-3 months to heal, most sac spider bites heal much more quickly, although the reaction will vary greatly from individual to individual.

Typical symptoms of a sac spider bite include a stinging sensation followed by redness and mild swelling. In a few cases, the bite may blister and break, leaving a sore that can take several weeks to heal. Sometimes the person will feel mildly ill.

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What spiders commonly bite humans?

There are about 2,000 kinds of spiders in the United States. Of these, only a few species are considered to have bites that are of medical importance. Spiders are very shy creatures. Most people get bitten because they are cleaning an area that has not been cleaned for a long time and they disturb a spider's web or nest. Spiders are often blamed for many more bites than they actually commit. In general, most spider bites will not harm most people except for slight discomfort for a limited time after being bitten. A few individuals may be hypersensitive to the bites of a particular species, but this allergic reaction won't be known until after the person gets bitten.

Although only a few spiders are toxic or cause allergic reactions, if one has been bitten, it can be important to save the spider for identification purposes.

Unlike the majority of spiders, black widow and brown recluse spiders are of concern because their venom contains toxins, that can cause medical problems. Other spiders to be aware of are the Parson and Yellow Sac Spiders.

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How do I prevent an infestation?

A consistent presence of spiders in structures may be a sign of an insect infestation because spiders cannot survive long without food. Reducing insect infestations will also decrease spiders.

Habitat modification is the most important tactic for good spider control. Whether indoors or outdoors, most spiders have a preference for undisturbed areas.

Install tight-fitting screens on doors and windows to prevent entry.
Seal or caulk cracks and crevices where spiders can enter the house.
Install yellow or sodium vapor light bulbs outdoors since these attract fewer insects for spiders to feed upon.
Be sure to dust and vacuum frequently around windows, corners of rooms, shelves, under furniture, and behind mirrors and pictures.
If you see spider egg sacs, remove them.

If you are concerned about spiders inside your home, place sticky glue boards in the rooms where you are seeing spiders, especially on outside walls and in closets, secluded areas. If you have an infestation of brown recluse spiders, you may want to work with a licensed pest control company.

For accidentally invading spiders (these are most frequent spider situations), we recommend that efforts be made to seal cracks and crevices as the most permanent solution.

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Who do I call if I suspect an infestation?
Just call S & W Pest Management at 1-877-989-BUGS to set up an appointment or fill out the online appointment form. We'll be happy to come inspect your home for termites and other pest and give you advice about the best way to fix the problem. We hope this guide is helpful to you, our valued customer.

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