The black widow spider is one of the most poisonous spiders often seen in North America. These spiders thrive at moderate temperatures and are mostly found in the south and western US regions.
They are often found in places surrounded by bushes, open areas such as outdoor bathrooms and toilets, open sheds, plants, and even in grape vineyards. The spider always finds a sheltered area where debris gets collected and finds a perfect place to build a web for its prey. The name "black widow" refers to a female spider with a shiny black-colored body. It is famous for killing and eating male spiders after mating.
One can easily distinguish black widow spiders from other spiders because they have red and white-colored marks on their upper body. Some may even have a red hourglass-shaped mark on the upper portion of their body.
Moreover, the severity of the reaction still depends on the individual’s age and overall health condition. Black widow spider bites tend to be more serious in young children and the elderly.
Do black widow spiders bite humans?
Black widow spiders are usually not aggressive. However, when they are disturbed or provoked, they do get aggressive and bite humans. Most experts have observed that black widow spiders are shy and always try to move away from humans. The spiders neither attack nor bite human beings unless threatened. Most spiders prefer to stay away from humans.
Humans pose a greater threat to spiders than spiders do to humans. The black widow spider is not dangerous unless people come in contact with it either by sitting over it or pinching the spider which makes it react. There are a few cases when people accidentally come in contact with the spider, which bites them either on the hand or other parts of the body.
Spider bite risks
The bite of a black widow spider could be dangerous since it could lead to death for older people and young children. People with medical issues and pregnant women should be careful of spider bites. Use objects such as a stick or long cleaning brush to lead the spider outside the house.
What does a black widow spider bite look like?
Black widow spiders have long hollow fangs, which they use while dealing with their prey. The spider passes the venom through its fangs by injecting it into its prey. Most spiders have fangs that are not strong enough to pierce the human skin. However, the fangs of the black widow spider are different from the usual ones.
A black widow spider bite shows up clearly with two red punctured marks on the skin. The mark can also be seen in a form of a red ring surrounding the red marks. The bite mark also resembles a target-like appearance. It may take 30-45 minutes before the person starts to experience pain, swelling, and skin redness.
Black widow spider bite symptoms
According to the American Association of Poison Control Centers, most black widow spider bites are not poisonous. It depends on most venomous spiders. The spider spreads its venom depending on the situation when it senses danger.
The symptoms of non-venomous bites are almost negligible. However, the symptoms of a venomous bite usually develop after 45 minutes to 2 hours.
Mild to severe pain may develop along with swelling at the site of the bite. The following symptoms may be experienced within 24-48 hours after the spider bite:
- Itchy skin with rashes
- Mild to severe stomach pain
- Stomach, shoulder, or upper backside cramps
- Chest pain or tightness
- Swollen face
- Watery and painful eyes
- High blood pressure
What to do after a spider bite
When a person gets bitten by the black widow spider, immediately call for medical help either by calling a doctor or taking the patient to the hospital.
1) Note down some useful information for doctors
- Patient’s age and weight
- Patient's symptoms and underlying health problems
- Time of the spider bite
- The affected part of the body
- The type of spider bite
2) Offer first aid while waiting for medical help
You can take care of the patient if medical help is delayed.
- Wash the bitten area using clean water and soap.
- Apply ice cubes over the bitten area.
- Make use of an antibiotic cream or lotion over the bitten skin.
- Keep the patient under close observation and watch out for other symptoms.
Diagnosis and treatment
Doctors will admit the patient and will be kept under observation if serious symptoms are recognized. Doctors can request for medical tests such as urinalysis, blood tests, X-ray, and an electrocardiogram (ECG or EKG) when necessary.
If the spider bite causes severe pain, and the patient suffers from serious symptoms, then doctors may use an antivenin along with antibiotics to help limit the poison.
How dangerous is the black widow spider?
There are more than 35,000 species of spiders around the world. Nearly 3,400 species of spiders in 64 families are mainly seen in North America.
Death from a black widow spider bite is rare. According to reports, the human mortality rate is almost below 1 percent. However, one should get immediate medical aid after getting bitten by a black widow spider.
Female black widow spiders
Female black widow spiders are nearly 0.5-1.5 inches long in size when they spread their body.
Female spiders usually have a red hourglass pattern on the underside of their abdomen. Some spider species have a series of red spots and crosswise bars on their underbelly. Most male black widows have yellow and red bands. The spots on their backs are only seen during their immature stages.
Newly hatched spiderlings are mainly white or yellowish-white in color that slowly turns into black. The juveniles of both sexes are harmless to humans.
Black widow spiders are well-known as large cobweb weavers. There are about six species of black widow spiders out of the 2,000 in the large Theridiidae family.
Types of spiders
Most species of the widow spider are found in the US. Latrodectus hesperus is one of the common species found in the western US and also in North American deserts. Latrodectus mactans is a black widow spider mainly found in the eastern and central US. The brown widow spider, Latrodectus geometricus, is also found in the US. The other species found in the US are:
- L. mactans - found in warm areas of the world
- L. geometricus - found in African countries and the US
- L. curacaviensis - found mainly in the US
- L. hystrix, L. dahli, and L. pallidus are commonly found in Southwestern Asia, Southern Europe, and Northern Africa.
The western and eastern black widow spiders spin webs that are not in any particular shape or form. Their webs appear to be erratic in nature and are made up of a stronger material, which makes the web rough and sticky. The black widow spider is shy and has a nocturnal habit. Black widow spiders try to stay hidden in their web. They mostly hung with their belly upward. Although the black widow spider is not aggressive, she might attach herself and bite if her cobweb is disturbed.
Most black widow spiders are found on the underside of ledges, plants, and debris. They can be found over rocks and open areas supported by shades. Spiders tend to enter houses or buildings during heavy rains, winds, and cold weather.
Food and hunting
Black widow spiders hunt by trapping their prey in their webs. They trap a variety of insects such as cockroaches, beetles, flies, and mud dauber wasps. Once the prey gets trapped in the web, the spiders make a hole and suck all liquid from their prey. It kills its prey slowly.
Most male black widow spiders are smaller than female ones. Male spiders move around in search of female spiders. In most cases, female spiders kill male spiders after mating.
After mating, the female spider lays several batches of eggs. Every batch will have about 750 eggs. The egg batch is about 0.5 inch in diameter and is suspended in the web. The eggs have a paper-like texture and are white to tan in color. The eggs get hatched within 1-4 weeks. Baby spiders will appear as orange and white in color. Only about 1-15 young spiders survive due to the attack and cannibalism by their fellow spiderlings. The life of most female black spiders is about one year or more. The life span of a male spider is about 3–5 months.
How to recognize a black widow spider
The female spider is recognized due to its red hourglass mark over its abdomen. The body of the black widow spider is smooth and shiny. It is up to 3-10 mm in size. The important characteristic of the black widow spider is its strong comb foot with curved bristles used while capturing its prey.
What does a black widow spider eat?
The black widow spider prefers a variety of insects such as ants, caterpillars, grasshoppers, beetles, cockroaches, scorpions, and other seasonal insects that it catches in its web.
Why is it called the "black widow spider"?
The spider was given the name "black widow spider" because of its mating behavior. Courtship begins when males go out in search of female spiders. Initially, the female spider gets interested in pairing but then kills the male spider after mating.