SPIDERS
     

Black Widow | Brown Recluse | Hobo | Giant House Spider

Treatments

Black Widow SpiderBlack Widow Adult females are approximately ½" in length. They are jet black in color with a distinctive red "hourglass" shape on the underside of the abdomen.  The males and immatures are smaller than the females and generally have yellow, white, and red bands and spots over the back.

The Black Widow Spider is not of particular concern around the Puget Sound region, as the number of recorded sightings has been very few. Occasional sightings, in our area, have been attributed to "stow aways" transported via shipped goods.

Bite: Though usually a non-aggressive spider, the Black Widow will strike when provoked.Most common bites are inflicted on persons whom unknowingly trap the spiders in clothing, shoes, etc. Outdoor laborers are also at risk through gardening practices, moving lumber piles, rubbish, etc.

The venom of the female Black Widow is a nerve toxin. The first sensation is a pinprick sharp insertion of the fangs, usually followed by a burning sensation for a few minutes. Pain usually progresses from the bitten member up and down the arm or leg, finally localizing in the abdomen and back. The abdominal muscles become rigid and board like, accompanied by severe abdominal cramps. Other symptoms may be nausea, depression, insomnia, tremors, speech defect, and a slight rise in body temperature. The bite is seldom fatal; however a medical physician should always be consulted immediately.

Brown Recluse SpiderBrown Recluse The Brown Recluse Spider is light tan to chocolate brown.A dark "fiddle-shaped" marking extends from just behind the eyes to the head and thorax.

Bite:  Both males and females have been shown to possess the capability of inflicting poisonous bites. Typical signs of a Brown Recluse Spider bite is necrosis or death of the tissue around the site of the bite. This bite is also typical of the Hobo Spider bite, which is why it is often mis-diagnosed. 

The venom of the Brown Recluse is said to be a hemolytic poison.Other symptoms may include dizziness, nausea, cramping and joint soreness. A medical physician should always be consulted immediately. This species has not yet become established in the Pacific Northwest .

Hobo SpiderHobo Spider Mature females are approximately 7/16 to 10/16 inches long in body length.  Males are slightly smaller. Females have 2 long spinnerets protruding at the end of the abdomen which has a “herringbone” stripe pattern of brown, gray, and tan. The legs are long and hairy. This spider is prevalent in the Pacific Northwest.

Bite: Necrosis (death of skin tissue) is a common result of a Hobo Spider bite. The necrotic areas, around the bite, are extremely slow to heal. The bite of the Hobo Spider is very similar to that of the Brown Recluse and is often mistakenly identified as such. The initial bite is not painful. Within 30 minutes, or less, a small hard area appears on the skin at the bite location.  This area is surrounded by an expanding reddened area anywhere from 2 to 6 inches in diameter. This is followed by blistering within about 24 hours. The blisters usually break and the wound oozes serum, forming an ulcerated crater that scabs over. Immediate medical attention is advised if you think you have been bitten by a Hobo Spider. Keeping this area clean and sterile is extremely important to guard against infection. Systemic illness my or may not accompany the bite. Headache, nausea, weakness, tiredness, and vision impairment are all documented results of Hobo Spider bites. It is not uncommon for the wound to take up to several months to heal and leave a permanent scar.

Giant House Spider This spider is often mistaken for the Hobo Spider because of its similar appearance. It often takes a trained eye, with the aid of a lens, to determine the difference. It is a related species of the Hobo Spider.

SPIDER TREATMENTS

Because they feed on many types of insects, spiders are generally thought of as beneficial. There are times and places; however when they are not welcome, and can be of danger.

For instance, the harmless garden spider or orb-weaver variety, which spin their webs in shrubs, threes, etc., are beneficial by catching gnats, flies, mosquitoes, etc. in their intricately woven webs. They are not a threat to bite humans or animals and are rarely found indoors. Treatment of such spiders is not recommended and is usually frowned upon by most respected pest control companies.

Conversely, large spiders found indoors and/or in close proximity to structures are not only a menace, but can be a threat to your family’s health.  Arachnophobia (fear of spiders) is an extremely common condition.

Most people have an inherent fear of spiders. Many people experience some level of Arachnophobia ranging from mild dislike and fear to intense fear which can cause a variety of psychological issues.

While treatment processes are effective, unfortunately it is not always as immediate and/or permanent as most people hope for. Spiders are habitually "shy" in nature and tend to "lay in waiting". Although treatment procedures likely will target these areas, not all areas are readily accessible or safe for pesticide application. Often there is a period of time where spiders will “flush out” following a treatment. This may last as long as a month. Another factor of treatment is having the patience for the spider to travel through pesticide residuals that have been applied in accessible areas.

As other insects (potential spider prey and food) are eliminated, due to treatment process, the spiders' food supply becomes non-existent. Females are forced to leave their web in search of food elsewhere. When this occurs, they are highly likely to trail through, and pick, up pesticide residuals on their leg and abdomen hairs which results in their death. Treatment also decreases/eliminates the male spiders, hence cutting off reproduction and the spread of spiderlings. Males tend to wander in search of females to mate with. Thus they are far more likely to pick up and succumb to pesticide residuals.

Professional treatment for spiders is usually very effective. Once the initial service has been completed, and has had time to take effect, a preventive maintenance program is recommended to keep spiders under control and away from and out of your home. Things to consider when formulating a successful maintenance program for your particular needs are: environment, home location (woods, heavy vegetation, etc.), your particular needs and wants, budget, among other things. LIND PEST CONTROL AND INSPECTION SERVICES, INC., is happy to take the time to research and discuss these factors with you in order to maintain a successful "bug free" zone to protect your home and family.

Sources:
  • Study manual for Pest Management Professionals, #MISC0096
  • Handbook of Pest Control/Mallis 9th Edition