Spiders found in Connecticut include 26 unique species from confirmed sightings by contributing members of Spider ID. It is important to remember that spiders seen in Connecticut are not bound by the territorial lines decided on by humans, therefore their distribution is subject to change. House spiders are common throughout the United States, including Connecticut, where the cold winters force many spiders indoors to simply survive. House spiders in Connecticut include the wolf spider, the American house spider, and the yellow sac spider; only the latter has a dangerous bite. Even though almost all of the spiders in Connecticut are venomous to some degree, the only two that most people need worry about are the black widow spider (Latrodectus spp.) and the brown recluse spider (Loxosceles reclusa). While any spider bite can cause a painful reaction if you are allergic, most bites can be treated by washing.
American House Spider
This species is among the more common spiders in Connecticut, in neighboring RI, MA and NY. Responsible for many of the cobwebs you see. Its venom is not considered dangerous, however there is a chance of allergic reactions in some people. The spider has a large round abdomen and thin legs.
Is very large and often takes an expert to distinguish individual species. Although these spiders prefer the outdoors, they are not uncommon inside the home especially during colder months when they seek the warmth and shelter of a house. These spiders intimidate some, with their formidable appearance and quick speed. Wolf spiders do not build webs, they are active hunters. An interesting characteristic is that their eyes are reflective, allowing them to hunt at night and be seen by the light of a flashlight or other light source.
Yellow Sac Spiders
They do not build webs, but instead small sacs in corners typically high above the ground. Sac spiders are generally pale yellow, yellowish-green or beige in color. Nocturnal, these spiders often run quickly along walls and ceilings. If they are disturbed, they will quickly release and fall to the floor. Sac spiders are medically significant, their bites can leave necrotic wounds, similar to (but not typically as dangerous as) the bite of the brown recluse or hobo spider.
Brown Recluse in CT
Connecticut is outside the natural habitat of the brown recluse spider or the hobo spider. The brown recluse, as mentioned, is known for a bite that can cause necrosis, or tissue death, despite the bite being painless in most cases. If you think you may have been bitten by a spider and an ulcer on the skin appears within a day and seems to be worsening, it could be the result of a recluse spider bite and you should seek medical attention.