S & W Pest Management Inc : Insect Guide

Pest Guide » Spiders » Black Widow Spiders:

Black Widow Spiders
Lactrodectus mactans
Color: Black, with characteristic red "hourglass" on back
Legs: Eight
Shape: Round
Size: 3/4" long; 3/8" around
Antennae: No
Flight: No

The black widow spider is widely feared because its bite. The black widow spider has a potent neurotoxic venom and is considered the most venomous spider in North America.The bites cause severe pain that may take several days to subside. However, the female injects such a small dose of venom that it rarely causes death. Reports indicate human mortality at well less than 1% from black widow spider bites. Bites most frequently occur when people are picking up an item under which the spider is hiding or putting on a shoe the spider has crawled into.

Adult males are harmless and are about half the female’s size, with smaller bodies and longer legs. Newly hatched spiderlings are predominately white or yellowish-white, gradually acquiring more black and varying amounts of red and white with each molt. Juveniles of both sexes resemble the male and are harmless. The characteristic red markings on the underside of the female's abdomen often connect to form an hourglass shape, but this does not always occur. Some specimens may have red-to-orange and ever yellow apearring on the top of the abdomen.

Black widow spiders spin their webs near ground level. They often build their webs in protected areas, such as in boxes and in firewood and often gain entry into a structure when firewood is carried into a building. They are also found under eaves, in boxes, and other areas where they are undisturbed.

Prevention:
Avoid black widow spider bites by wearing heavy gloves when moving stored cardboard boxes, firewood, lumber, and rocks .
Spiders often hide in shoes, so check shoes and shake them out before wearing.
When spider webs are visible, use caution before putting your hands or feet in that area.
Install tight-fitting screens on doors and windows to prevent entry of black widow spiders.
Seal or caulk cracks and crevices where spiders can enter the house.
Install yellow or sodium vapor light bulbs outdoors since these attract fewer insects for spiders to feed upon.

If you would like to make an appointment with S & W Pest Management, please fill out the online appointment form or call 1-877-989-BUGS.