The end of a stressalicious semester

Today is officially the last day of instruction, but there won’t be much instruction going on — it’s all administrative stuff for me, acquainting students with the record of their past performance, pointing at the specter of the imminent final exam like a ghost of Christmases yet to be, polishing up that final exam and posting it for them to procrastinate and worry over, the usual bad time at the end of a difficult school year.

Next year will be better, right?

It could be worse. Look at these spider photoreceptors!

It turns out that if spiders aren’t properly fed, their photoreceptors start to die off.

Researchers looked at the bold jumping spider (Phidippus audax), a common species that relies very much on light-sensitive photoreceptors in its large eyes to spot prey. When the spiders don’t get enough nutrients, these photoreceptors can be lost.

“Photoreceptors are energetically costly,” says biologist Elke Buschbeck from the University of Cincinnati. “It’s hard to keep up with their energy needs.”

“If you deprive them of nutrition, the system fails. It’s the functional equivalent of the macula in our eyes.”

See, if I don’t have enough research time to take care of my spider colony, they might go blind. I’ll run that by the administration and see if I can get a reduction in teaching load.*

*Note: it will not work.

Araneus gemmoides left us a present last year

For the last few years, we’ve been graced with regular summertime visits by cat-faced spiders, Araneus gemmoides. They’re great big orbweavers, usually no trouble at all, although last year one of them took over our deck, stringing webs over the doors. We let her. When you’re that beautiful, you can get away with anything.

One of the reasons they’re no trouble is that they just lurk, and then when winter arrives, they die. Last year’s visitor crept up above our back door and left an egg sac in a dark corner. Here it is!

We got a step ladder to get closer, and I poked a lens right in there. The sac was partially torn open on one side (predation?), so I got a good view of the eggs inside.

Those are definitely spider eggs, but they aren’t very far along in development. It’s been chilly and snowy for the last few weeks, so it’s not surprising that they haven’t matured much. Maybe Minnesota will be kind and bring us a real spring soon?

I’ll keep you informed about this developing subject!

Mighty Morphin’ Spiders

Last month, I thought I’d found a color morph in S. triangulosa: some recently caught wild spiders from Wisconsin that were almost solid black, with just a hint of the standard pattern. I figured I’d be able to do some crosses this summer and see if it was heritable.

Now I don’t need to! Look at the difference a month in the lab environment makes.

[I try not to splash spiders in your face here. You’ll have to look it up on Instagram or Patreon.]

That’s the same spider, almost a month apart. Now it looks all the other spiders I’ve got. I suspect it’s got to be something about the change in diet, from whatever they were finding in a garage to a steady diet of fruit flies and mealworms.

They were caught in Wisconsin, where they’d been living on cheese curds, brats, and La Croix, probably.

Also note that this spider has made a couple of egg sacs. The one in the top right is a half-assed mess, only a few eggs only partially wrapped in a thin skein of silk.

Tower of Spiders

We’re currently isolating all freshly laid egg sacs and tagging them with the date so that we know exactly how old the embryos are. This week I started scanning all the adult containers and setting aside those who had produced an egg sac.

It started out well: one on Sunday, one on Tuesday, one on Thursday, and I’m thinking this is perfect — a fresh batch of 30+ embryos every other day is what we can handle easily. Then then this morning, Friday, I come in and…5 new egg sacs for 21 April.

Then I realize…Thursday is quarter taps night at the Met Lounge downtown. Have they been sneaking out for a wild party night, and then coming back to the lab all primed for reproduction? That’s the only rational explanation.

I could be concerned that I’m going to be in another situation where the lab is drowning in more spiders than we know what to do with, but we’re about to switch paradigms a little bit. Next week we start plunking lots of embryos into fixative, then the week after we start doing embryo dissections and staining with propidium iodide. None of these spiders are going to live to adulthood. Sorry.

What beast emerges from the dark depths?

This is exciting. I’ve written about my compost bin before, which has been a rich source of spider lore — a partially closed habitat, the domain of some large dark spiders that build their cobwebs in a place rife with buzzing insects.
The bin has been inaccessible for months, buried under snow. Today the snow had retreated enough that we could hobble over slick, crunchy ice to get to it and throw back the lid. What did I see?
First, fresh silk, new cobwebs laid across the corners. Somebody had been working hard. Then, suddenly, at one side, a massive spider loomed out of the darkness — a fully grown, adult male Steatoda borealis. His presence tells me something: he’s much too large to be a recent hatchling, so he must have overwintered down in the dark, sheltered from the storms, huddled in the fermenting warmth of the compost.
We closed the lid and let him be. I’m sure there are more down there who will creep out in the next few weeks to rebuild a thriving colony.

If you want to see this massive unit of a tough Minnesota spider, you can go to Patreon or Instagram. He’s big and dark in shades of red and black with thick strong limbs and glowing eyes.

Signpost of Spring!

For me, the first sign of spring is when I’m walking around and start seeing thin filaments everywhere — the little threads of silk left behind by traveling spiders. This year the first delicate threads spotted were on campus, draped over the metal signposts around the parking lots. They’re all webbed with criss-crossing strands!

I didn’t see the spiders there, not yet, just these traces. From past experience, those signs are often populated by Theridion, so I’ll keep my open for the first appearance of the little guys.

Teaching outside my comfort zone

Today is a busy, frightful day. I volunteered to stop by the Morris Area High School to give away some spiders and talk in general about the importance of spiders, and I don’t exactly know what I’m doing. College students are one thing, but middle school and high school kids are completely different beasts. I’ve done this before, and mainly what I come away with is the feeling that we don’t pay teachers enough.

I’m meeting with 7th and 10th grade biology classes this morning and afternoon. I’m bringing in a lot of baby spiderlings which are tiny and hard to see, not impressive at all, and a couple of larger adults. I’ve also got several egg sacs, one of which is very, very close to eclosion — maybe we’ll get a sudden eruption of spiderlings, which would be exciting. I’m going to propose leaving a half dozen spiderlings in the classrooms, along with a supply of wingless fruit flies, and recommend that they take care of them for a few weeks, and then on some bright spring day, to release them in a grassy area near the school.

I’ve been researching lesson plans lately, and unfortunately, almost all of them have been geared for younger kids — K-6. I’m not going to talk down to this group, so I figure I’ll just explain a few scientific details and open the floor to questions.

They’re going to eat me alive, aren’t they?

The Renfield protocol

They don’t tell you about the dirty jobs involved in spider care. Last week, I fed all the adults nice big juicy mealworms, which they promptly killed and then spent several days sucking on their vital fluids. Even when they’re very thorough in their consumption, though, they still leave behind a sack of chitin with organic leftovers inside.

Then it rots.

It rots thoroughly, turning black and soft and turning hairy with fungus. It has a sulfurous reek to it, as well. Then the spiders turn to me and peremptorily demand, “Renfield! Oh, Renfield! Do clean up the rotting corpses, will you? That’s a good Renfield.”

Renfield is me, if you haven’t figured that out. This morning I got to go through all the cages and pluck out decaying mealworms with a pair of forceps. This is my job. That, and regularly bringing them fresh bodies to turn into rotting corpses.

Oh well. I also got to play with my shiny new camera and take photos of my masters.

You’ll have to go to Instagram or Patreon if you want to see photos. (Hmm, I didn’t do a very good job of promoting those links with all this talk of decaying corpses, did I…)