Spiders are likely to be found wherever their food – insects and small arthropods – is available. Many species are household pests, however the most common in the states of Washington and Oregon are the Orb Weavers, Giant House, Hobo, and Western Black Widow.
All spiders have 8 legs, 2 body parts, and fang-like mouthparts. These characteristics can make it fairly simple to distinguish many spiders from insects, however it can be very difficult to distinguish one spider from another. This is because many species can look similar, while spiders within the same species can vary considerably depending on the life stages they are in. For this reason, spider identification needs to be conducted by an expert, often through a microscopic examination of its anatomy.
Orb Weavers
Color: may be a wide range of shapes and colors. One common orb weaver of the northwest has a white cross on its back.
Body Size: up to 1/2-inch in length
Found in: Orb weavers build very organized, circular-grid webs anywhere with abundant prey and structures to support the web – around light fixtures used at night, tree branches, tall grasses, and bushes. Many orb weavers build a new web each day, thus their webs are generally free of dirt and dust.
Threats: Although orb weavers can give a painful bite, they non-aggressive, fleeing at the first sign of a threat, and are considered to be beneficial.
Giant House Spider
Color: brown to grayish brown
Body Size: 1/2- to 1-inch in length, with leg span up to 4 inches
Found in: Very common in the Pacific Northwest, the giant house spider prefers indoor dark areas. They are often found in garages or basements, as well as outdoors in firewood or in gaps between bricks or stones.
Characteristics: This spider is non-aggressive, generally fleeing when threatened. Its bite is not generally known to be a threat
Hobo Spider
Color: grayish brown with herringbone or chevron patterns on the abdomen; on the underside, a light tan center with dark bands around. Legs are brownish yellow with no stripes
Body Size: 1/2- to 1-inch in length with long legs
Found in: Hobo spiders construct a funnel-shaped web, preferring outdoor areas, such as window wells, holes in concrete or soil, and under large rocks, boards and debris. Indoors, they are usually found in basements or ground floor levels.
Threat: The bite is usually painless, but within 15 minutes a burning sensation and reddening may occur; then the bite area enlarges, and within 3 days blisters may form. The spider’s venom is strong enough to cause considerable local pain and a severe allergic reaction in some people.
Western Black Widow
Color: female is black with distinctive red hourglass shape on its back. Males have tan body and legs
Body Size: about 1/2-long rounded body
Found in: Black widow spiders are generally found outdoors where insects are plentiful. They often spin their webs near doors and vents or in protected areas, such as in boxes and wood piles.
Threat: The black widow bite is generally painless, but within an hour symptoms start to appear. In addition to a little red mark or red streaking away from the bite, these may be simply flu-like or may include rigid stomach muscles, sweating, pain, urine retention, numbness, agitation, fever, and patchy paralysis. If bitten, medical attention should be sought immediately.
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Spiders: The Problems
- Spider bites are the most common problem with this pest. To avoid bites:
- Wear heavy gloves when moving stored items.
- Check shoes and shake them out before putting on.
- Use caution before putting hands or feet in any area where spider webs are seen
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Pioneer Spider Management
More than 3,000 spider species found in North America, and each has its own unique characteristics. In addition, many species differ enough that the control techniques used against one may not be effective against another. Thus, it is essential to accurately identify and treat for the specific species that is present.
Spider management is a part of Pioneer Pest Management’s Home Defense and Commercial Protection ongoing maintenance programs.
To protect your family, home, or business:
- We inspect the property to identify and locate the spiders and determine necessary and proper management activities.
- We will implement Integrated Pest Management (IPM) strategies where viable and will recommend areas of exclusion, sanitation, or other actions you can take to help reduce spider attraction, means of entry, and future invasion.
- As a part of the Pioneer Home Defense and Commercial Protection programs, we will maintain a constant vigilance against new populations and respond to any such service request you may have.