Last Wednesday, I was so optimistic. I’d paired up Vera with a first-generation son of Gwyneth (GI-♂), they’d gone at it hot and heavy, and had produced an egg sac — an egg sac with a peculiarity I’ll get to in a moment. My plan was to go in today and open up the sac and see what embryos I’d find.

The peculiarity was that although I’d classified all my spiders as Parasteatoda tepidariorum, there was still a little uncertainty. The patterns of pigment on their cuticles were a bit ambiguous. Here’s part of the description of P. tepidariorum from Common Spiders of North America.

This is a medium-sized to large cobweb weaver. The abdomen appears teardrop shaped as the spider hangs updide down in its web, spinnerets uppermost. The cephalothorax is tan or brown. The abdomen color is extremely variable, usually shades of light brown with a mottled tan or brown. Some individuals are nearly black, others unmarked and pale. The legs are darker at the joints.
…
The egg cases of this spider are tan and tardrop-shaped, point uppermost.

This describes my spiders perfectly, given that there is variability in the patterning of the abdomen. They look different, which had me worried that I may have gathered a couple of different species, but then the description of the egg case settled it for me: Gwyneth had produced lovely tan, teardrop-shaped egg cases. Case closed, right? Gwyneth and her progeny were P. tepidariorum.

Then Vera produced an egg sac. Vera herself also fits that description of P. tepidariorum to a T.

But the egg sac she produced was a cottony, pure white ball. What? I flipped through my books looking for some indication of what this might mean, and found a description of Steatoda triangulosa, which is also common in this part of the country.

This is a medium-sized cobweb weaver. The cephalothorax is reddish brown. The legs are light brown with dark brown bands. The apdomen is light brown with two rows of angular spots or bands of dark reddish brown separated by white areas with a mottled appearance. In some individuals this pattern looks checkered.
…
The egg case is a fluffy white sphere.

Uh-oh. Are Vera and Gwyneth from two different genera? There’s nothing in Vera’s abdominal pattern that fits S. triangulosa, but maybe that’s highly variable in this species, too, and the egg case definitely fits this description. But she’d bred with P. tepidariorum! Were the new eggs hybrids? Was I just a terrible ignorant klutz playing the taxonomy game poorly? I went into the lab to take a few steps towards finding out.

And…disappointment. The “fluffy white sphere” was gone — it had been torn apart. The eggs within were dried up lumps. Uncertainty reigns.

I put the two lousy parents into a petri dish and made a video. You look and tell me: Parasteatoda tepidariorum or Steatoda triangulosa? Looking at just the adult morphology, I’m saying P. tepidariorum, but what do I know. Video below the fold, with an agitated pair of spiders scurrying about.

[Read more…]

It’s all good news. All the spiders are thriving right now, chowing down on flies. Vera produced a very pretty egg sac — I’m thinking the 14/10 light/dark cycle may have something to do with it — and has shrunk to about half her previous size. I’m planning to open up the sac on Sunday as part of my devotional, just to check on the health of her embryos. Although I’m low on adults, the next generation is coming along, and with any luck I’ll have a swarm of spiderlings this time next week.

Disaster struck this weekend. I gave my fully-grown, big ol’ adult spiders crickets to eat. Now Vera is a monster: she just ropes ’em up, immobilizes them fully, and then bites them. So I was overconfident and gave crickets of the same size to Amanda and Xena.

The next day, Vera is a huge bloated sack of bug juice and her cricket is in fragments. Amanda and Xena are gone, and their crickets are sitting there smug and happy. Turns out crickets defend themselves by kicking predators, and poor Amanda and Xena were beaten to death and then eaten by the evil Gryllidae. This does not make me happy. I’ve got to find a safer food source. For now, I’m just giving the juveniles and the sole survivor lots of fruit flies. Death to all crickets!

In other spider news, I’ve been frustrated by the fact that none of them are producing eggs right now, and all the wild specimens have vanished from their usual haunts as winter descends upon us. Then, last night, I woke up in the wee hours with a sudden obvious thought.

Remember that movie, Silent Running?

There’s this scene where the space-going ecologist is concerned about how all the trees are losing their leaves, which are turning brown and falling off, and he hits the books trying to figure out what disease is killing his forests. And then he suddenly realizes, oh, autumn, seasons changing, all that, and I’m sitting in the audience thinking, you dope, of course, so he runs around setting up lights to create a growing season in the space domes. Yeah, I’m also a dope who didn’t think of that, and I should have, because I’ve got timers and lights for my fish rigged to put them on a 14/10 light/dark cycle. This is routine lab animal maintenance. D’oh!

So now I’m going into the lab this morning to put up lights and trick the spider colony into thinking it’s Spring, and time for love, by wiring up the incubator.

Today was cricket-feeding day. I am still learning things, and one of the things I have learned is that I hate crickets, those jumpy, twitchy, annoying little beasts. I have to struggle to confine and catch the things, but I chortle evilly when I finally slide them down into a vial. They’re two or 3 times larger than my spiders, but it’s no contest. They’re doooooomed. Bwahahahaha!

Also, spiders have personalities. Amanda is shy; she gets a cricket, she ignores it, and me, and just hangs out in her corner placidly until I leave the room.The cricket will be dismantled fragments the next day, but a lady does not make a spectacle of her murders.

Xena is timid. She notices the cricket for sure, but she runs away — where it is, she is not, and she scurries about rather frantically to avoid it. She lays down lots of webbing, though, and I think she waits until it snares itself thoroughly before going in for the kill.

Vera is a beast. Put anything in there, she does not delay sinking her fangs into it. I’d just put the cricket in her vial when she charged up, lassoed its hind limbs, and was making quick bites into the leg joints. She reminds me of Gwyneth, a real killer. Especially that bit about first knee-capping her prey before getting into the serious business of liquefying its guts.

Vera also escaped, briefly, and marched up onto my hand and stood there, gently tapping on my knuckle like she was getting impatient. Once the cricket was in her vial, though, she quickly rappelled down and made short work of it.

I’ve got to get them some mates, but I’m worried that the juvenile males are just too small — I may try tomorrow, though, when the females are fat and sated with cricket juice and might be willing to tolerate a conjugal visit. I’ve got a son of Gwyneth I’d like to pair up with Vera — what beautifully voracious slayers their progeny might make!

(I might be getting a little too close with my arachnid brood, I willingly confess.)

The last time I mentioned my spider work, I had sad news: the eggs were dreadfully dessicated, and I hypothesized that the declining humidity was not good for their health. I have no new egg sacs, but I did increase the humidity in the incubator, and have other good signs to report. There has been zero mortality among the juveniles this week, and the adults were extraordinarily lively — so lively that I had to deal with 3 escapes while I was trying to feed them.

I had spiders crawling all over me, which was a delightful feeling, but also made me a little panicky — I had to get them back into their nice safe vials before they got injured. All were rescued, no harm done, and they also immediately chowed down on the juicy flies I’d given them.

I felt all paternal and warm inside, as one does when dealing with affectionate pets.

I had such high hopes this morning — necessary reagent had arrived, I had a nice egg sac, I was going to open it up and spend my afternoon exploring embryos. It was not to be. I teased apart the egg sac, and what do I find? Heartbreak. Disappointment. Failure.

The eggs were all dead. I’m not sure what happened here, but I have a hypothesis: this summer and early fall, I had all these fish tanks in the lab, gurgling away, and the place was pretty humid. Now those are shut down, and it’s winter in Minnesota, when the air dries out. Spiders like some degree of humidity, and I’ve been maintaining that by regularly misting their vials with an atomizer, but maybe that’s not enough for the embryos.

So I’m cranking up the moisture levels in the incubator. Now I’ve got to worry about balancing everything — too much and I’ll have to worry about mold and fungus.

Babies are such fussy little creatures.

There’s a surge in the spider population going on, and people are calling it an Arachnid Apocalypse.

It isn’t just your imagination. Scary sightings of larger-than-usual spiders are on the rise in Metro Vancouver this fall.

Pest control specialist Randy Bilesky has seen a 50 per cent increase in calls to his service this season over last.

“People panic … we get the phone call after someone has walked through a spider web,” said Bilesky. “They are sure it’s still in their hair, especially if it is one of the big hobo spiders.”

I prefer the term “Spider Renaissance”.

What next? Is everyone going to start complaining “Oooh, there are too many squid in the ocean” and “Ick, there are prokaryotes crawling around in my colon”?