Black Widow Spider
Black widow spider is a common name for several venomous spiders in the genus Latrodectus, best known for the female’s shiny black body and red hourglass marking.
Black widow spider refers to several venomous spiders in the genus Latrodectus, best known for the female's shiny black body and red hourglass marking. Their bites can cause significant pain, but fatalities are rare in healthy adults.
What it is
The name covers several species of widow spiders found in temperate regions worldwide. The term "widow" comes from the female's occasional post-mating cannibalism, though this behaviour is less common in nature than the name suggests. Females are glossy black, often with a red hourglass-shaped mark on the underside of the abdomen; males are smaller and lighter in colour.
Why it matters
Black widow venom is neurotoxic and can cause pain, muscle cramping, sweating, and nausea. While bites are rarely fatal, they are medically significant. In North America, multiple species occur, including regions near southern Canada, making them a relevant concern for prompt medical attention if symptoms appear.
Key details
Females reach about 1.5 inches (3.8 cm) long. Bites are serious but not deadly for most healthy adults. The red hourglass is a key identifying mark on the female's underside. They are recognized in temperate habitats, including parts of Canada.
In short
- Black widows are venomous spiders with a red hourglass marking.
- Fatalities are rare, but bites can cause severe pain and cramping.
- Found in temperate regions worldwide, including parts of Canada.
- Females are more medically significant than males.
Black widow spiders are relevant to Canadian readers because some Latrodectus species occur in North America, including regions near or within southern Canada, and bites are a recognized medical concern in parts of the continent.
Quick questions
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Sources
- Encyclopaedia Britannica — https://www.britannica.com/animal/black-widow-spiderSupports: Genus Latrodectus, number of species, hourglass marking, and name origin
- National Geographic Kids — https://kids.nationalgeographic.com/animals/invertebrates/facts/black-widowSupports: Scientific name, size, lifespan, venom effects, and North American species reference
- Smithsonian Magazine — https://www.smithsonianmag.com/science-nature/eight-fun-facts-about-black-widows-180978098/Supports: North American species names, female size, appearance, and venom effects
- National Geographic — https://www.nationalgeographic.com/animals/invertebrates/facts/black-widow-spidersSupports: Worldwide temperate distribution, venom effects, bite severity, and defensive biting behaviour
- Connecticut Agricultural Experiment Station — https://portal.ct.gov/-/media/CAES/DOCUMENTS/Publications/Fact_Sheets/Entomology/Northern_Black_Widow_Latrodectus.pdfSupports: Northern black widow as medically significant in the Northeast