I’m sorry to disappoint, but looking at my Steatoda borealis population, I think what I’ve got are dimorphic males: some with huge spiky palps, some with slender pencil-shaped palps. I have no idea if these are distinct subtypes, or just developmental differences.
I have the full story on Patreon, and posted some photos on Instagram.
Lesbian spiders would have been cool, though, unlikely as that was.
Yesterday, I set up a cage for Steatoda borealis. I haven’t successfully raised them in the lab, probably because I haven’t fine-tuned their environment, but I thought I’d give it another try. I caught these individuals living in a communal environment (my compost bin), so I made a substrate of moss, for burrowing in, and added 5 females, all in the same confined space.
I came in today, and what do I find? They’ve built a communal web and they’re all perched on it, spaced about 2cm apart. This is already interesting.
Something to know about S. borealis: the adult males are distinctive, they have palps that look like massive medieval instruments of war, while the females have slender palps. I was pretty confident I’d segregated them by sex accurately, on the basis of casual inspection.
So I added a male this morning. All the spiders seemed somewhat agitated, there was much scurrying and tapping and exploratory sensory behavior, as I would expect. The male was courting the biggest, plumpest female in the cage.
Then, to my immense surprise, two of the females (I think) paired off, and one of them was aggressively thrusting its skinny little palps at the others genitals. Whoa, what? Did I misgender them, or was this some kind of social behavior?
Then I get dragged away to attend some fucking meeting, and couldn’t inspect them more carefully. This was extremely annoying, as you might guess.
Now I’m intensely curious. I’ve searched the literature, there is no mention of male dimorphism in this species, but it’s an interesting possibility that warrants further investigation. The other possibility is female:female sexual behavior — these spiders are somewhat social compared to others I’m working with, so it could be some kind of bonding behavior? Another possibility is that I’m fooled by juvenile males that exhibit typical sexual behavior but just haven’t completed their final molt to acquire their gloriously developed sexual organs.
I’ll be putting them under the microscope tomorrow to find out.
Classes start in one week (there are also way too many meetings this week), and I’ve been housebound far too long, so this weekend is my last chance to escape for a bit before the crunch hits. And then I discover there’s an Exotic Pet Fair in Eau Claire this weekend. Perfect! It’s a twofer — I get to visit my granddaughter, and take her with us to go spider shopping. I’m in the market for a nice show tarantula for the lab, and maybe a black widow or two.
It’s not all spiders. They also have birds, reptiles, bunnies, guinea pigs, etc., so even a kid who isn’t that much into spiders should be entertained. I’ll also be glad to just get out for a day.
(Don’t worry — I’ll consult with experts, and won’t be getting any endangered species. If we get Latrodectus,I think I can keep them reliably confined. I don’t want to go do down in history as the guy who populated the basement with black widows, like the former professor who let cockroaches loose in the building.)
An 8-year old boy in Bolivia picked up a black widow spider and urged it to bite him (this isn’t as easy as you think, black widows are shy and reluctant to bite) because he wanted to become Spider-Man. This is a worthy goal, but his methods weren’t particularly effective. A doctor explained:
“These black spiders with red backs are black widows. They do not cause anyone to become Spider-Man—on the contrary, they are putting lives at risk,” Vásquez said.
The kid is fine, but this has happened before!
In 2020, a similar case occurred in the rural Bolivian town of Chayanta, in the Andean region of Potosí, involving three children aged 8, 10 and 12 respectively. The trio provoked a black widow spider to bite them with the same objective. Doctors also managed to successfully treat the children in that incident as well.
Clearly, further public education is necessary. The children of South America must have it explained to them that the procedure requires a radioactive spider.
Hey, any millionaires/billionaires out there want to shovel money at me to feed spiders radioactive food and allow them to bite me?
Our new development in spider development is pretty basic stuff. We’re dechorionating embryos! That is, stripping off a thin membrane surrounding the embryo, so we can do staining and fixation and various other things. It’s a standard invertebrate technique — it turns out you can remove it by just washing them in bleach. Look, it works! This is a Parasteatoda embryo.
We’re still tinkering with the timing of the treatment. Five minutes is way too long, which basically dissolved the whole embryo. All it takes is a brief wash to break the chorion down. We’re also working out methods for manipulating them — they’re tiny! Just pipetting them into a solution is a great way to lose them. We’re now using a cut off microfuge tube to make a cylinder that we cap with a sheet of fine nylon mesh, to lower them into the solution. Of course, then we have to separate the embryos from the mesh. Fortunately, we opened up one egg sac and 140 embryos rolled out, so we have lots of material to experiment on.
The next question is whether they survive our abuse. We’ve got some of them sitting under a microscope, time-lapsing their response. We’ll see if they grow…or die and fall apart.
We get a livestream in about an hour on candy-striped spiders and how to take good macro photos with your phone. Tune in!
My wife and I tend to wake up far too early — just this morning she was complaining that she woke up at 3am and couldn’t get back to sleep. Me, I’m a lazy bones who snoozed until 4:30am.
But here’s a possibility: there are spiders that go hunting for sleeping prey at night, the Enoplognatha, or candy-striped spiders. All we need to do is get our boots on, gulp down some coffee, and drive out to a few places we know of that are frequented by hapless pollinators. Actually, maybe we should be checking out our backyard garden in late evening/early morning.
You know, you could help out, too. They’re pretty little spiders.
As mentioned, my task for this morning was murdering spiders. Mission accomplished, and now I feel terrible.
It was a simple procedure. I put the vials of happy gamboling spiders into the refrigerator to calm them down and numb them — I gave them about 15 minutes of chill. Then I went into each vial with a paintbrush and teased them out, and they descended into a tube of icy, pre-cooled alcohol, where they died within minutes. Now their bodies are packed into a freezer, awaiting delivery to the person who will chop them up.
The worst part was going through the assortment of spiders in the colony and having to choose which ones would die.
You have to understand that this was the very first time I’ve had to kill an adult spider. I’ve been wiping out embryos right and left, and I’ve had adults die of natural causes — but actually terminating their existence by my hand? Unpleasant. I like my spiders lively and interesting. I’m a biologist, not a necrologist.
One of our goals this summer is to map out the developmental stages of our embryonic spiders, and to that end we made our first crude, short timelapse recording this afternoon. Aren’t twitching baby animals so cute?
Here you go, an excellent introduction to the spiders I work on, the false widows.
I should probably require all my students to watch it, because it strikes a good balance on something I struggle with: venom. I tell my students it’s medically significant, a bite can hurt, and the venom can make you sick, but at the same time I tell them I’ve never been bitten, I handle them all the time, and as long as you’re gentle, there’s no real danger.
Also interesting is the geographical difference. I’ve never seen Steatoda grossa or S. nobilis around here — it’s all Parasteatoda (I know, different genus), with some S. triangulosa and rare S. borealis in specific habitats. McEnery makes the interesting hypothesis that it may be the venom, that Steatoda generally makes a venom that’s significantly more potent against invertebrates than the venoms of native species, allowing them to thrive and take over.
