Sorry, Seattle, you’re not special

Every year, there’s a little freak-out from Seattle communities about spider season.

Seattle’s annual spider season has arrived, driven primarily by mature male giant house spiders actively searching for mates indoors during August and September.

We never noticed anything in particular about spiders in the fall when we lived there. I suspect it’s nothing but a media-fed frenzy that has little connection to reality.

It’s also not a Seattle thing. We get a surge in spider visibility in the fall, too, and it’s simply because some common spider species that live near humans are in frantic mating mode as the warm weather starts to go away. Relax.

I will say, though, that one spider-fact that’s special about Seattle is the swarms of cross spiders, these spectacular orb-weavers, that are everywhere. I remember them from when I was a kid. Or rather, maybe what’s special is that where I live now is totally lacking in Araneus diadematus. We’re in a weird hole in its range.

Too many spiders?

A colleague found this lovely grass spider scampering about the hallways, and she brought it to me (this is a routine event every Fall). I happily took it and brought it home, in my left hand.

Then as I was leaving the science building, I spotted a lovely bold jumper on the glass door. Of course I caught it in my right hand.

I’m hurrying home with spiders in each hand, and when I got home, there was a zebra jumper waiting on the door. I thought about pulling a Darwin and popping one of them into my mouth so I could catch the third, but I didn’t want to traumatize any of the spiders, so the zebra jumper was let off, and is having a lovely time in the garden, where all of them eventually ended up.

The wolf spiders are raiding

My wife keeps coming home from work with spiders she rescues.

They’ve been invading her work place. This is a common event as the weather cools — the males are desperately looking for last-minute mates, and are checking out even the unlikely places.

Now I face a problem. They are escaping the cold wet weather, is it really a kindness to release them outside? We haven’t had a freeze yet, so it’s probably OK to let them go in the dating pool of my yard. A little later, I might start turning them loose in the basement party room.

The North of England has been blessed with a new invader

She’s beautiful.

Argiope bruennichi

The colloquial name is the wasp spider, and they’re not normally spotted in Cheshire, but one was found in a recent survey. There is some concern when a non-native species shows up — is this a sign of climate change? Also, English northerners are not accustomed to these big honkers.

“You know your big, chunky house spiders – the ones you think are massive and frighten the life out of you in your living room? A female wasp spider is probably a bit bigger than those,” said Scott Wilson, head of field programmes at the zoo.

I’d be thrilled and surprised if I saw a wasp spider — they’re native to Europe and North Africa, and I haven’t seen any here. We instead have two equivalent native species, Argiope aurantia and Argiope trifasciata (we have a lovely A. aurantia living in our backyard right now). Maybe they are a sign of a warming trend in the UK, but they are quite nice animals, inoffensive and helpful in clearing out your grasshoppers and crickets. They just look a little intimidating. Don’t be frightened.

A Cambrian chelicerate!

I’ll have to show my spiders this reconstruction of their great-great-many-times-great grandmama. She’s adorable.

Megachelicerax cousteaui

It’s all in the chelicerae.

In a study published in Nature, Research Scientist Rudy Lerosey-Aubril and Associate Professor Javier Ortega-Hernández, Curator of Invertebrate Paleontology in the Museum of Comparative Zoology, describe Megachelicerax cousteaui, a 500-million-year-old sea predator discovered in Utah’s West Desert. It is the oldest known chelicerate, the arthropod group that includes spiders, scorpions, horseshoe crabs, and sea spiders. The discovery pushes the evolutionary history of chelicerates back by 20 million years.

Hey, I’ve visited the West Desert of Utah — but all I found were fossilized trilobites. Lots of trilobites. Megachelicerax food. But I never found a predator like this one.

The key feature identifying it as a chelicerate are those big clawed appendages on the front of its face, which is also a prominent feature of modern spiders, much modified. The appendage is now a crushing/chewing anvil, and the thumb of the claw has evolved into a wicked needle.

Its most extraordinary feature, however, is its unmistakable chelicera — the pincer-like feeding appendages that define the subphylum Chelicerata and distinguish spiders from insects. While insects possess sensory antenna as their foremost appendages, chelicerates have grasping, often venomous tools. Despite a rich Cambrian fossil record, no unambiguous chelicera-bearing arthropod from that time had ever been found – until now.

The thing about modern spiders is that they’re mostly defenseless — no sting, no pointy legs, no claws — except for that one extraordinarily useful weapon, the chelicerae. Well, they also have silk, making them a kind of retiarius of the arthropod world. You’re probably not afraid of their webs, but you worry about their big chompers and the venom they carry.

I don’t think the retiarii would have poisoned their tridents, though.

Grisly & horrible

Sometimes my spiders make me queasy. This is the reality of nature, though.

I fed my Parasteatoda a mealworm this morning, and sadly, the spider was not particularly effective in killing its prey. It’s been gnawing on the worm for over 4 hours, while it writhes and twitches. It was frantically writhing away most of the day as the spider clung to it, nibbling.

Spiders are predators, you know.

The image quality is bad because I recorded it through the plexiglas of its container. At least it blunts the horror.

Definitely not for kids.