The compost bins are coming alive!

I got word from a colleague* that their compost bin was accumulating spiders again — they had a swarm of them last spring, that disappeared over winter — so I had to check it out. I opened the bin and was disappointed at first, because while I saw lots of cobwebs all over the decaying vegetable matter, there was nowhere near the number of spiders I’d seen in the spring.

I finally spotted one in a corner. Steatoda borealis, the same species that had thoroughly colonized the bin before.

Steatoda borealis is an interesting theridiidid. They seem to be the native species to this area, with the more common house spiders being immigrants from either Eurasia or South America, depending on the species. These beasts are bigger than the others, and I haven’t seen them in houses or garages much, mainly outdoors or in special environments like this compost bin. I’ve got some in the lab, and they seem less active than Parasteatoda or Steatoda triangulosa, but that may be because I’ve only observed them in the day.

I spent several moments poking around in the bin, taking a bunch of photos, making a note to myself to come back in a week or two. Then I started to lower the lid. The lid I’d been holding up all this time with my left hand. Only then did I notice that it was covered in webbing, and there were all the spiders, lots of them, gettin’ busy busy beneath my oblivious fingertips. Squeee! Jackpot!

So I had to take a bunch more photos. These spiders were paired off all over the place, mating furiously! I took photos of these wonderful piles of tangled legs, 16 at a time with agitated bodies having a grand time.

You’ve probably heard about female spiders killing their mates and eating them, but that doesn’t happen so much in environments rich in food. Steatoda and Parasteatoda can happily coexist in sprawling web communities where lots of insect life is rising up from a festering mass, and they don’t do the cannibalism thing in those circumstances.

I did notice one lonely male off to the side of a mating pair, staring intensely. I hope you find your true love soon, little guy!

Definitely going back here later. It’s a wild little hotspot for spider orgies.

This post also appears on my Patreon account, complete with spider photos. The photos are also posted on Instagram and iNaturalist.

*A colleague in math. Curious fact: two of the professors in our math discipline have the most interesting spider populations in their yards. Is it something about mathematicians that attracts spiders?

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.

There be spiders under there!

Beneath that huge pile of drifted and shoveled snow beside my garage lies buried my compost bin, legendary home to many generations of spiders (especially Steatoda borealis) and maggots. I couldn’t seen any spiders before the last big storm, but now I can’t even get to it. It’s completely covered in an avalanche of snow.

This is probably just fine for the occupants. Lots of spiders overwinter by snuggling down under the layers of snow, and others just tuck away an egg sac and let the embryos rest quietly until the spring. I’ll be checking in as soon as it melts and it warms up a bit more.

Classes resume in two weeks! <brain screaming>

I think I’ve got it under control, probably, although the internal sensations of doom and helpless descent into a spiral of chaos will continue until December. I’m meeting my co-instructor for cell biology this morning to synchronize our watches and re-attune our wavelengths, and my syllabi are nearly done, except that the other day the administration sent out another wave of boilerplate we have to attach to them. I don’t get the point of most of it; these are pages and pages of cover-your-ass copy that every single class will give to every student every semester for the next four years, and I’m pretty sure they all read the syllabus to get the list of readings and the dates of the exams and then skip the rest. I don’t blame them. That’s what I’d do.

On top of that, my spiders are erupting in babies right now, with another egg sac due to hatch out in the next day or so. My plan is to pull out a sample that I can set aside for observation, and the rest will be set free in my garage to hopefully prepare for overwintering. I’m curious to see how Steatoda triangulosa will do in a home environment, anyway. Maybe some will populate the compost bin, too?

I’ve got about 150 spiders in the incubators right now, which somewhat stresses me out with the burden of feeding every other day. And now I have to also feed students’ brains on top of that? I may have to set some priorities here.

The most horrible video I’ve ever made

This will be popular, sure.

My compost bin is extraordinarily productive in producing maggots, which makes the spiders living in there very happy. The resolution here isn’t great — I used my el cheapo camera, since I was plunging it down in close to the writhing mass of larvae. If anyone insists, I suppose I could redo this with a reasonably good macro lens.

Everything is real time — no time-lapse. That’s how fast they move! Also, listen carefully and you can hear them eating. It sounds a bit like soggy rice krispies.

It’s only a minute long, so don’t worry, it ends quickly. If anyone also insists, I could record a much longer video.

No one will insist.

I know this will make some people queasy, so I’m hiding it below the fold.

[Read more…]

Morning surprise

We’ve had an animal raiding our compost bin late at night. They’ve been burrowing underneath to get at the rotting vegetables in there, and then scattering them over the yard. This isn’t good. The bin is there to keep the decaying organic material confined rather than just flung about all over the place.

We’ve had this problem before — a couple of times now, we’ve had groundhogs living under our deck. We have a humane trap that we use to catch them and then we transport them a few miles away to somewhere near the Pomme de Terre river, where we release them. This is practically routine now.

So we set up the trap last night, went to bed, and bright and early this morning I go out to check on things. I blithely stroll out to the other side of the garage, and…oh shit.

I backed away quickly. I know that skunks can easily spray 10 or 20 feet, and are shockingly accurate (they aim for the eyes). They can also be mean little guys. This is about the worst thing we could have caught.

My current plan is to wait until 9 to call the local animal control office and make sure they don’t have a policy for dealing with wild animals in city limits. Then if I must I’ll approach the cage with garbage bags as a shield and open it up and let Pepe LePew go.

Lesson learned. Don’t set traps unless you’re prepared to deal with what you catch!

Happiness is a pocket full of maggots and spider eggs

Our compost bin is thriving! We found some new egg sacs inside it, like this one:

It’s strange. It’s orange. We suspect it might be Mimetus, the pirate spider, but time will tell. I took it into the lab and will have to wait for it to hatch out.
The other compost development is that it is full of squirmy busy maggots. I’m talking dense sheets of a multitude of swarming maggots. I scooped up some and brought them in to see if the spiders would eat them. They liked it! (The spiders, not the larvae.) This will be an alternate food source, at least over the summer. I think it’ll slow down a lot once the temperature drops below freezing.
In other news, I’ve been doing weekly measurements of the growth of my Steatoda triangulosa babies. They’re all (except one, sort of) growing well. Here’s a table of the mean dimensions of the young spiders.

I know, not exactly exciting, and I have to plod through more weeks of measurements. Note the big surge in length this week! That’s because they all molted on Day 22, and shedding that exoskeleton gave them more room to stretch.
I mentioned one spider was an exception. Spider #5 is looking a bit odd. Still growing, but suddenly their limbs and palps have gone pale…I’m hoping they’re not sick.

The Great Spider Heist

One of my colleague has a lovely compost bin in their back yard. Or should I say, “had”. They’re leaving our fair campus for a new job in the big city of Madison, which caused me some worry — not just for losing a good contributor in the science & math division, but because, as I’ve reported before, their compost bin has a magnificent colony of Steatoda borealis thriving inside it. Nobody ever asks, “what about the spiders?” when they leave.
So Mary and I…ummm…”appropriated” the compost bin. Don’t worry, I asked permission first, and it has now been relocated to our yard. Just outside our door, where I can check on them regularly.
Is it not beautiful?

It was a disruptive process for many of the spiders. The bottom is open, so hoisting it up meant losing much of the compost inside, but we shoveled up much of it and restocked the bin. No doubt we lost some spiders in the move, but they mainly live in the tangle of webbing inside the lid, not in the compost itself. Lots of egg sacs were still there.

And of course, many agitated spiders scurrying about on the lid.

They live on the small insects that emerge from the decaying compost, and survive the winter on the warmth of the fermenting organic matter, so I threw in some old potatoes I’d been saving for this occasion. We’ll also be much more careful to toss food waste in there, to keep the spiders happy.
We’ll also rename the bin the Atkinson Home for Hungry Spiders, in honor of my colleague.
Although, I don’t understand why he didn’t want to pack up such a gorgeous box full of joy to bring to his new home.

This story has also been posted to Patreon, and I’ll post occasional updates on the status of the happy spider family there.

Hey, how about some local good news for a change?

Incremental progress exists, and I should acknowledge that now and then.

  • Morris is implementing organics pick-up! The county is collecting food waste from local grocery stores and restaurants for composting. It’s a drop in the bucket, but a good step.
  • This is impressive: Alexandria (a city about 45 minutes north of me) is partnering the police with mental health professionals to put the right people in charge of handling citizens having mental health crises. Imagine: someone having a breakdown and the city response is not to send an unqualified thug with a gun charging in to do battle.

We’re taking baby steps in the right direction, let’s keep it up.