Black widow spiders have been found in every state. They are a lot less numerous in New England than further south — their abundance is inversely related to the latitude — however, the northern black widow, Latrodectus mactans, (pictured) is here. According to Dr. William Spear, a noted arachnologist and provider of the information in this post, a black widow in northern New England would need a very sheltered site, such as the south-facing walls of buildings, south-facing sides of ditches, or perhaps even in barns and sheds, in order to survive.
The web of the northern black widow is a rather small (for the size of the spider) messy tangle, usually constructed close to the ground. The spider is generally not found on the web, but in a silk-lined pocket to one side and above the web. The silk of widow spider webs is unusually tough, and with experience one can learn to differentiate it from other spiders’ silk just by testing the web with a stick or pencil.
If knowing that black widows cohabit your state causes some discomfort, rest assured. Their bites are very rare and almost never fatal. The few fatalities that have been recorded are generally from children or persons weighing less than 100 pounds, or with precarious health. (Photo taken by Evan Kay in North Pomfret, Vermont in September, 2014; submitted by Caroline Robbins)
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Several recent studies demonstrate that wild birds are actively transporting ticks and their associated diseases during migration. In addition, a number of bird species are able to contract Borrelia burgdorferi (the bacterial causal agent of Lyme Disease infection) and transmit it to uninfected ticks that parasitize the birds for a blood meal. Since ground-feeding species such as Northern Cardinals, Gray Catbirds, Song Sparrows (pictured) and American Robins spend a significant amount of time foraging for food at the optimal height for ticks, they are excellent hosts and have all demonstrated the ability to infect larval ticks with Borrelia burgdorferi upon their first blood meal. (Look carefully at the Song Sparrow’s neck and you will find a tick.)