Identified a poisonous widow spider with white marks or spots on a large abdomen. Pictured below is a venomous spider that belongs to the Latrodectus genus, in the Theridiidae family.
Latrodectus is a genus of spider which contains 32 species. The more common name is WIDOW SPIDERS.
Widow spiders belong to the cobweb spider family. They spin irregular, sticky webs to catch insects. Widow spiders possess a row of bristles on their hind legs that form a comb, which is easily seen in the photos. The comb is used for flinging silk over its prey.
The black widow poisonous spider is perhaps the most common of the genus. Widow spider bites are dangerous because of the neurotoxin which causes the condition latrodectism, (pain, seizures in muscle groups) — this is where the name for the spider genus came about,Latrodectus.
The female Latrodectus spiders have unusually large venom glands and its bite is particularly harmful to humans; however, Latrodectus bites rarely kill humans if proper medical treatment is provided.
Symptoms of a poisonous widow spider bite:
Once the spider’s poison reaches the blood, the venom is moved by circulation, causing its toxins to be deposited in the ends of the nerves that are inserted into the muscle.
The spider’s venom acts at nerve endings to prevent relaxation of muscles, causing seizures —constant, and painful muscle contractions. Cramping in the stomach is frequently the most severe but leg and back muscles may be affected also.
What to do after being bit by a widow spider? SEEK medical attention after a poisonous spider bite.
Most people will recognize widow spiders by the hourglass markings on the underside of their abdomens. The hourglass mark is NOT present in ALL Latrodectus species.
In arid parts of Arizona, Latrodectus spiders inhabit almost every crevice in the soil and nests can be found in cholla cacti and agave plants.
The female’s spider venom is at least three times more potent than that of the males.