Black widow spiders (Latrodectus mactans) is a highly venomous species of spider that is a native species to the United States. Canada and Mexico. The Northern Black Widow spider can be found in British Columbia, Alberta, Saskatchewan, Manitoba and Ontario. They are rare to find, but they generally like to hang out around trash piles, sheds, under rocks, wood piles, etc. Anyplace that is dark and a little damp is a great place for them to hide.
Female black widow spiders are known for their distinctive black and red colouring and their sometimes habit of eating the males after they mate. The mature female black widow spider is usually around 1.5 inches long and about .25 inches in diameter. They are shiny black with a red mark in the shape of an hourglass on the ventral (under)side of their abdomen, which is very round. The sizing of the female black widows can vary especially in egg-carrying or gravid females. The abdomen diameter in a gravid female can be more than 0.5 inches.
Mature male black widow spiders are very different in appearance to the females. Males are much smaller than females with their bodies at less than 1/4 inch. Their colouring is usually black but often they take have a similar appearance to that of juvenile black widow spiders. Juveniles have a distinctly different appearance then the females (and some males) in that their abdomens are greyish to black in colour with white stripes running across them spotted with orange or yellow.
Black Widows will typically prey on a variety of insects, but they will also sometimes feed on woodlice, diplopods, chilopods and even other aracnids. When their prey gets entangled in their web, the black widow will wrap the prey securely with web and then bite and envenom the prey. The venom takes up to 10 minutes to work and then digestive enzymes will be injected into the wound of the prey. After that the black widow will carry their prey back to their retreat where they will feed.
Despite being known as highly venomous spider, there is not much to worry about. In an article here Antonia Guidotti, an entomology technician at the Royal Ontario Museum, says while black widow sightings make headlines, Ontario is not exactly undergoing a scourge of the famed eight-legged arachnids.”The black widow is very rarely encountered. Most of us, even entomologists, haven’t seen a black widow in the wild in Ontario. Most of you are never going to see one. And the risk if you come across one is very small,” she assures.Guidotti says even if one should have the misfortune of encountering a black widow, the spiders present a much smaller danger that we’ve been led to believe.