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.

The spiders were all fed this morning, and I continued my efforts to get breeding to happen. Maybe it did; I’d left the female New Arya (it’s a cursed name, we’ve gone through three Aryas so far, although this one seems to be lasting) with a male over the weekend, and initially I wasn’t certain what was going on. New Arya is slightly peculiar, having built a nest of debris in one corner of her cage, rarely leaving it. When last I left our two lovebirds, the male was hovering about the nest, plucking forlornly at the web, and New Arya was just waving a tootsie at him.

This morning, though, New Arya was outside (she’s on the left) near the male (on the right), and the two were just resting…in post-coital bliss, perhaps? I hope? I didn’t have the heart to break up the peaceful pair today, so I left them alone, for now. That male has more copulatory duties with other females, though, so I’m going to have to break them up this week.

See? Female spiders aren’t necessarily cannibalistic widow-makers.

Speaking of nesting, I found Mary Jane huddled in a corner with a dome built over her head. It looks cozy.

She seems quite content to have a home of her own. I suppose I’m going to have to introduce a male at some point, though, and wreck her maleless paradise.

Latrodectus umbukwane is a breath-takingly gorgeous spider from South Africa. Look at those colors!

As you might guess from the genus, it’s related to black widows, which means of course everyone gets worked up about its potential venomous nature. It hasn’t bitten anyone that we know of! Get over it! It seems to be, if anything, unusually shy.

Also, you want to see some sexual dimorphism? Take a look at this.

Well, this is a stupid sensationalist headline: New Species of Spider Found in Mexico Able to Rot Human Flesh. Yeah, so? This is a common property of many venoms, such as those in some wasps and snakes, and it makes sense that a spider, which relies on injecting toxins and enzymes that break down cells and tissues, would do so. How else would they slurp out the digested guts of their prey? These spiders have no interest in eating people, or “rotting human flesh”, so it’s an obnoxious way to distort the story.

I can just imagine spider tabloids running stories title “New Species of Primate Found With Large Fleshy Butts Capable of Crushing Innocent Spiders”. It completely misses the story.

Here’s a pic of the lovely beast in question.

It’s called Loxosceles tenochtitlan, and it’s distinguishing characteristic is not that it has a remarkable venom, but that males and females have unique genitals in a lock-and-key arrangement, which is also common in invertebrates.

In a statement released by the university, Valdez-Mondragon explained the difference: “As L.tenochtitlan is morphologically similar to L.misteca, it was initially thought that it had been introduced to this region by the shipping of ornamental plants. But when doing molecular biology studies of both species, we realized that they are different.” Valdez-Mondragon described the species and noted the difference between L.tenochtitlan and L.misteca lies in the male spider’s palp or the organ that enables touch in arachnids. It is also noted that the female L.tenochtitlan has a distinct looking sexual organ compared to L.misteca. Valdez-Mondragon explains that at first glance, the two species of spiders can look identical, but L.tenochtitlan can be identified because of its dark brown color which is dull compared to the other species and on its back is a very visible violin pattern.

The story goes on to claim that “humans are naturally repulsed at the sight of “creepy crawlies” like spiders.”

The Science Times is not one of my approved popular science sites. Too much trash written by people who have only the most passing acquaintance with science.