Black widow spiders are common in Phoenix, Arizona, and the southwestern United States in general. Nocturnal creatures, they hide in the dark corners of garages, sheds, firewood piles, and are commonly found during camping or hiking. Less than 1 percent of all people bitten by this spider are at risk of dying, and most of them are saved by the use of an effective antivenom. In fact, only four people die on average annually from poisonous spider bites (of all varieties of spiders) in the US.
If you experience severe symptoms after being bitten by an insect, including what you think may be a black widow spider, seek medical attention immediately or call 9-1-1.
Black widow spider details
Females are the only member of the species that actually bites. The body of a black widow is shiny black (or sometimes brown) with the characteristic red “hourglass” shape on the lower abdomen. A female can reach a half inch in length with long, slender legs up to twice her body length. The abdomen is large and bulbous, teardrop shaped when viewed from the side, ending with a pointed “row”. She will usually be found hanging upside down in her net with the red hourglass clearly visible.
The female will rarely leave the web. The female lays her eggs in a cloth sac attached to her cloth. She can be very aggressive in defending her eggs.
Black widows can be found in North America, from Canada to Mexico and in the West Indies. There are many black widows in Arizona and Phoenix. Twenty-two different types of black widow spiders live in every corner of Phoenix and the Sonoran Desert.
To identify a black widow web, look for a web that appears as if it was spun by a very drunk spider. The black widow generally spins a very messy-looking web that bears little resemblance to the stereotypical, neat, and symmetrical web of most spiders. If the spider is not hanging upside down from the web, it is most likely hiding on the outer edge of the web or even in a nearby dark crevice or corner.
How to avoid a bite
Black widow spiders rarely bite humans. If you think you see a black widow spider in its web, then leave the creature alone. Spiders, like almost all other animals, will avoid humans and flee if any escape route is left open. Do not allow children or anyone else to push sticks on the web or disturb the spider. The animal may get angry or scared enough to bite. This is especially true if there is an egg case present.
Probable Encounters
Black widow spiders can be found throughout the year. The population will peak during the warm months, which is when last year’s hatchling will mature and new eggs will be laid and hatched. Due to the mild Arizona winters, some will even survive the cold season outside, but will generally seek more sheltered spots to spin their nets and may even try to move indoors.
If you visit Arizona for camping and hiking, look closely before using an outdoor latrine. Black widows are commonly found in the corners and under the seats in these buildings. An encounter can be very dangerous (not to mention extremely painful and embarrassing).
Be especially vigilant in secluded rustic cabins, storage buildings, attics, and driveways. These are places that humans rarely go and their main insect prey is abundant. Around the house, they will often be found in the garage, in the back of the pantry, or in any corner that is out of the traffic pattern. Be very careful when unpacking seasonal clothing or gear. In the garden, you can find their nets among the interior branches of bushes and trees. Rather than just grabbing pots, nets, or tools that are not in use, you should carefully examine each and every one of the webs, spiders, or other unwanted creatures.
Black widow spider bite symptoms
A black widow bite can feel like a prick, or it might not even be felt at all. Widow spiders inject a toxin that affects the nervous system (neurotoxin). Muscle and chest pain or tension are some of the most common reactions to black widow toxin. Although extremely painful and temporarily debilitating, deaths from untreated widow bites are rare. The very old, the very young, and those with a history of high blood pressure are most at risk. Immediate medical treatment can greatly reduce the danger.
You may notice two faint red spots surrounded by local redness on the bite. At first, there may be only slight local swelling. The pain usually progresses up or down the bitten arm or leg, eventually localizing to the abdomen and back. There may be pain in the muscles and soles of the feet, and the eyelids may become inflamed.
Other symptoms can be nausea, profuse perspiration, tremors, difficulty breathing and speaking, and vomiting.
In more severe cases, a weak pulse, clammy skin, loss of consciousness, or seizures may occur.
Treating a black widow spider bite
If it bites you, stay calm. If possible, collect the spider for positive identification and get immediate medical attention. If you visit Arizona, you can call a 24-hour toll-free number to access the Banner Poison Control Center at 800-222-1222.
Clean the bite well with soap and water. Apply a cold compress to the bite to minimize swelling and keep the affected limb elevated to about the level of the heart. Apply a mild antiseptic such as iodine or hydrogen peroxide to prevent infection. Don’t try to suck the poison. That does not work
In severe cases, doctors may inject calcium gluconate intravenously to counteract most of the effects of the toxin. A black widow antiserum is also available.
