Medical information (UC IPM Online)
The black widow bite itself is painless or may feel like a little pinprick. Almost all medically important black widow bites are from the adult female, which is much larger than the male; the female also has stronger biting muscles and a larger venom reserve. At the site of the bite, you might see a little red mark or red streaking away from the bite. Within an hour, symptoms start to appear.
Bite victims might suffer from some but not all of the following symptoms: rigid stomach muscles, which some medical professionals have misdiagnosed as appendicitis; sweating, sometimes of just the bitten body part, such as a bite to the hand that results in only the arm sweating profusely; pain that can be local, radiating, or regional; urine retention; and—less commonly—numbness, agitation, fever, and patchy paralysis. Another symptom is bite victims will move or rock back and forth incessantly to try to lessen the pain from the venom injection process. However, these symptoms are the most severe manifestation; many black widow bite symptoms merely resemble the flu. Black widow bites don’t cause conspicuous swelling, necrosis, or deterioration of tissue around the bite.
As a neurotoxin, the venom of a black widow affects the nerve-muscle junction in the body. Normally the body’s neurons work like a light switch; they make the muscle, or “light,” turn on and then off again, so that the muscle can relax and be ready to contract again if needed. The venom causes the muscle to repeatedly contract. It would be like flipping on a light switch and not being able to turn it off again.
If bitten, seek medical attention immediately. You can place a cold pack on the bite to relieve the pain. An antivenom for black widow bites is available that works for all species that have been tested, worldwide. Response is fast, and bite victims can go from intense pain back to normal in 30 minutes. The antivenom is based on horse serum, so physicians need to monitor for anaphylactic shock. American physicians are somewhat reluctant to use antivenom for this reason and might prefer to have the bite victim simply endure the symptoms, which can be similar to a bad flu episode and that usually dissipate in a few days.
It is good to know what can happen when bitten, however, widow spiders tend to be very shy, are nocturnal and would prefer to run instead of stand and fight. They will most likely be encountered outside the home in clutter, dark areas where they can hide during the day. Ideal places are in children's toys, under lawn mowers, in sprinkler boxes, wood piles, and I tend to find them under the siding of my house.
The best method of control is to clean up the clutter in the yard and garage. Make sure your doors and windows are sealed, this is good not only to exclude spiders but other potential pest invaders. Non-chemical control is best done at night since widows are nocturnal, go out with a flashlight and a good shoe. Chemical control for spiders is difficult because usually within a couple hours the spider is able to walk over the spray without harm. Usually one must spray the spider or its web directly for effective control.
So the moral of the story is, be aware of spiders and their hiding spots. Chemical control can work but is difficult and not very affective, the best method of control is manual extermination. Keep yards and garages clutter free and make sure your doors and windows are sealed. And remember, the world is beautiful, Black Widows are beautiful, we just need to be aware of our environment and enjoy every minute of it.
Thanks to UC IPM Online and for more information please see their site: http://www.ipm.ucdavis.edu/PMG/PESTNOTES/pn74149.html.
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