Another day in the lab, waiting for spiders to hatch out. They keep teasing me. While I was looking for egg sacs, though, this guy stood out. That’s a chonky big Steatoda borealis.
Note the light horizontal band across the front of the abdomen, and the hint of a midline stripe, all against a darkly pigmented body. These are true native spiders, found in the northern US in the midwest and east, and also in Canada. Parasteatoda tepidariorum is, apparently, also native to North and South America, but has spread all around the world, unlike these stay-at-homes.
S. borealis is also more stocky than P. tepidariorum. Here’s the latter to remind you what they look like.
Now I’ve got to wonder what has made S. borealis so well-tuned to these places with snowy winters.