Hello,

That is a Northern Widow Spider, Latrodectus variolus (Araneae: Theridiidae).

Northern Widow Spider is found throughout the eastern US, from southern Canada south to Florida, and west to eastern Texas, Oklahoma and Kansas. In Michigan, they appear to be more common in the western Lower Peninsula. Outdoors, they are found in old stumps, hollow logs, under fallen fence posts, in abandoned animal burrows or piles of brush, and in the corners of sheds and crawlspaces. In the northern black widow, the distinctive "hour glass" marking on the underside of the abdomen is incomplete or split in the middle. Northern widows also have a series of red spots along the dorsal midline of the abdomen, and the immature forms have a series of lateral white stripes on the abdomen. The web of the black widow is an irregular mesh of strands in which the spider hangs in an inverted position.

Surprisingly, as common as this spider is, black widow bites are rather infrequent. Even though widow spider venom is highly toxic widow bites are usually not serious due to the small amount of the venom injected into the bite. There is less than 1% mortality (mostly children) of persons bitten by black widows. The toxin affects the central nervous system and the severity of the bite depends on many factors including the age, size and sensitivity of the victim, location and depth of the bite, and when the spider last used her venom. Pain is felt almost immediately after the bite and increases for 1 to 3 hours but may last for 24 hours. In severe cases, large muscles become rigid with spasms, there is a rise in body temp, blood pressure, profuse perspiration, and a tendency to be nauseous.

This from Bugguide.net at http://bugguide.net/node/view/26421

Remarks

Caution: This spider is venomous and can harm people. 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. (Net Ref (1))

While Latrodectus variolus is not aggressive and does not have the instinct to bite, her venom is neurotoxic, which means that it blocks the transmission of nervous impulses. If the spider bites, most likely it has been pressed against human bare skin, and this causes a natural reaction, a bite in self-defense. For the most part, the black widow's bite may be felt only as a pin prick, during which the spider's fangs inject a minute amount of highly toxic venom under the skin. The severity of the victim's reaction depends on his or her age and health, and on the area of the body that is bitten. Local swelling and redness at the site may be followed in one to three hours by intense spasmodic pain, which can travel throughout the affected limbs and body, settling in the abdomen and back (intense abdominal cramping, described as similar to appendicitis), and can last 48 hours or longer. Elderly patients or young children run a higher risk of severe reactions, but it is rare for bites to result in death; only sixty-three having been reported in the United States between 1950 and 1959 (Miller, 1992). Other symptoms can include nausea and profuse perspiration. If left untreated, tremors, convulsions and unconsciousness may result. When death does occur, it is due to suffocation.

For more general information about the Widow spider, please refer to http://bugguide.net/node/view/1999

If you are bitten by a widow spp. spider:

Contact your physician, hospital or poison center immediately and follow their instructions. Poison Centers across the country now have a new national emergency phone number - <personal data hidden>.

Collect the spider if possible for identification. Your physician may administer an antivenom treatment and calcium gluconate to alleviate pain, and will probably treat the site with antiseptic to prevent infection.

If you have a heart condition or are otherwise vulnerable, you may require a hospital stay until symptoms subside. Usually bite victims recover fully within two to five days.

Precautions:

Be very careful when working around areas where widow spiders may be established. Take proper precautions-wear gloves and pay attention to where you are working. The reaction to a widow bite can be painful, and the victim should go to the doctor immediately for treatment.

Best regards,

Howard

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