Brad Gregory of Belding, MI (about 30 miles NE of Grand Rapids, MI) was bitten by a southern black widow spider (Latrodectus mactans Fabricius) on September 7, 2008. The spider was found inside a Maytag dishwasher that his grandparents had purchased at Home Depot two weeks earlier. He was treated at Spectrum Health System's Blodgett Hospital in East Grand Rapids, which had the antivenin on hand.
The best news article on this is from the Greenville, MI Daily News, which also includes a picture of Brad holding the spider in question. A quote from this article:
Doug Reeves, assistant chief of the Michigan Department of Natural Resources' Wildlife Division, said he's seen about seven northern black widows, "usually when I'm digging around woodpiles."
"They're not particularly rare but they're not something that's found, unless you look in the right habitat," Reeves said.
Doctors told Gregory that his was one of only one or two southern black widow bites ever recorded in Michigan.
"They told him he would have a much better chance of winning the lottery," Margaret Gregory said.
Reeves said he'd never before heard of a southern black widow bite in the state. However, Reeves said he's heard of other cases where non-native spiders and snakes have come into the state through international shipments, as was the case with Brad Gregory and his southern black widow.
The southern black widow spider is not a common Michigan spider.
Some more reading:
Latrodectus mactans on the Animal Diversity Web, a good survey, on its habitat:
A terrestrial environment is the habitat of the. It is ubiquitous and builds strong-walled retreats quite close to the ground and in dark sheltered spots. However, it also spreads its snares over plants. Webs of the black widow spider can be found in recesses under stones or logs in a woodpile, in crevices or holes in dirt embankments, in barns and outbuildings. They can also be found around lids of dust bins, around seats of outdoor privies, spaces under chips of wood, around stacked materials of any kind, in deserted animal burrows or rodent holes, and entwined in grape arbors. This spider may find its way into clothing or shoes and occasionally seeks a spot in a house to build a web, but it is usually not found indoors. When it does seek shelter in a building, it is due to cold weather and a need for a dry shelter. In addition, in the eastern United States, is associated with littered areas, with dumps of large cities, with garages, and storage sheds. In arid parts of Arizona, this spider inhabits almost every crevice in the soil and its nests are found in cholla cacti and agave plants. (Ferrand, 1988; Kaston, 1953; Preston-Mafham, 1984; Comstock, 1948; Gertsch, 1979; Shuttlesworth, 1959; Snow, 1970; Smith, 1980; Emerton, 1961; “Black Widow Spider, www.nscu.edu)