I was reading about Greta Binford, the spider-woman, and there’s a lot of good stuff here. I was a tiny bit put off by this bit, though:

Binford came late to the study of spiders, and without morbid predilections. She grew up on a small corn- and-soybean farm in west-central Indiana—“dull spider country,” she calls it.

I’m afraid Minnesota might be even duller spider country, and I’m a bit concerned about the lethality of our winters — it might be a very seasonal spider country. But that doesn’t make them less interesting. I’ve already got some ideas for experiments to test mechanisms our local populations have for coping. Also, even in winter I’m finding lots of spiders indoors, just not the species I was focusing on.

Binford is forgiven, though. She’s most interested in spider venoms, and that’s not a particular strength of upper midwestern spiders. I’m more into development and behavior, so there’s plenty to keep me occupied here.

But this bit rings true, for sure.

The key to good hunting, Binford said, was to have a “search image” in mind. Wolf spiders, for instance, can be found by their eye shine. When you train a flashlight beam over your back yard at night and see a faint glimmering in the grass, those might be spiders gazing back at you. Loxosceles tend to splay their legs like asterisks, and to gather in pockets of dampness—anything from the bottoms of rotting logs to the spaces behind steam pipes. “It reminds me of hunting for morels as a kid,” Binford said. “There’s a kind of Zen moment where everything falls away and there’s just you and the spider.”

The stairs led down to a long, open space, with pipes and wires hung low from the ceiling. Bits of graffiti flared into view, as our headlamps swung past, and strands of webbing caught at our faces. Most of it belonged to pholcids, or daddy longlegs, Binford assured me. Their venom is strong enough to kill a mouse, and they prey on other spiders, but their fangs are too small to hurt us. She played her beam along the bottom of a wall and held it on a Steatoda, a bulbous relative of the black widow, famous among arachnologists for turning radioactive and biting Peter Parker in the recent Spider-Man film. Then she stopped and scanned the room from end to end. “It’s like an Easter-egg hunt,” she said. The spiders were hiding in plain view.

I’ve experienced the same phenomenon! I’ve been walking these halls for years, totally oblivious to spiders, and now that I’ve started seeking them out, they’re everywhere! I find myself looking in corners, and window frames, and crevices, spotting cobwebs or fragments of chitin, and tracking down these little guys who share our homes and office buildings. If you’re an arachnophobe, I recommend not ever looking for them, or you’ll start spotting your nightmares all around you. Don’t develop that search image in the first place.

But don’t worry.

Spiders have a bad reputation, largely undeserved. The great majority aren’t venomous enough to harm us, or their fangs are too small, or their jaw muscles are too puny, or they simply see no profit in attacking large, indigestible creatures that can crush them with their toes. Unlike snake venom, which is designed to kill vertebrates, spider venom is almost always meant for insects. Its toxins can stop a hornet in mid-flight, but they lack proper targets in the human nervous system. “If we were wired for spider venoms the way insects are, we would be screwed,” Binford says.

She is studying Loxosceles laeta, a more potently venomous relative of the infamous brown recluse, which is infesting a Goodwill building in Los Angeles. I don’t know if you’ll find this part of the story reassuring.

When Binford milks laeta in her lab, their fangs yield about ten times as much venom as other Loxosceles’, and medical records suggest that their bites leave larger lesions. Yet, even if the Goodwill’s population spread across Los Angeles, it isn’t clear how much of a threat these spiders would pose. Laeta are easily as reclusive as their North American cousins. They keep to dark, quiet areas and shrink from human contact. When they do bite, the venom doesn’t always have an effect: some people’s immune systems aren’t sensitive to Loxosceles toxins. Five years ago in Lenexa, Kansas, a family of four trapped and killed more than two thousand recluses in their nineteenth-century farmhouse. Yet no one in the family suffered from a bite.

I would love to find a building with thousands of recluses lurking in it, but it’s not likely. They don’t seem to have taken to living this far north. But this might be one of the advantages of climate change, you never know.

This is funny, but I have never seen a bolas spider. Have you?

They’re on the checklist of Minnesota spiders, though, so they exist this far north. I’m going to have to make finding one an objective of my summer research plans. They’re nocturnal, though — I might turn into that weird guy poking around in the neighborhood bushes and trees late at night. I swear, officer, I’m not a peeping tom, I’m just looking for arachnids.

Hmm, the cemetery might be a safe place for nocturnal spider watching.

I was just reading about these recently identified genera of Central and South American mygalomorph spiders, Paratropis and Stormtropis, and got a little thrill from the photos, so I had to share. Their eyes are mounted in a little turret-like structure bulging up above the cephalothorax, and when you flip them over, oooh, those fangs. All black and pointy.

I know some of you don’t get that excited about spiders, especially ones that hairy and weird-textured and equipped with especially prominent bitey gear, so I’ll hide them below the fold.

[Read more…]

I’ve been playing with a few other species, and now I really want a cat-sized salticid for a pet.

I should let you know about this article, The ultimate lovely legs competition: the world’s nine most beautiful spiders, although I’m not too thrilled with the premise. It’s not a competition, all spiders have lovely legs…and chelicerae and eyes and abdomens and cephalothoraxes.

(I didn’t include any photos in this post because I’ve learned that some of you get so overwhelmed by the beauty that you close your eyes or close the browser window and go have a nice lie-down, and I didn’t want to disturb your work flow.)

It’s Thursday, which means it’s my spider clean up day — feeding and removing withered dead corpses from their vials, and also bottle-washing and general tidying up.

I’ve also been working on compiling some resources for students, since in a few months I have to sit down with a few of them and teach them how to identify spiders (challenging, since I’m a novice myself). For everyone’s general edification, here’s a short list of websites with taxonomic information:

• The University Extension Service on spiders (very basic overview.)
• Minnesota Spiders (spotty, incomplete; photos of a few spiders.)
• iNaturalist Spiders of Minnesota (iNaturalist is going to be a very handy tool.)
• Spiders of Minnesota: A checklist (good, detailed list; not particularly helpful for ID since it assumes you know what you’re doing.)
• A Preliminary Checklist to the Spiders (Arachnida: Araneae) of Minnesota (Part of the above checklist.)
• Bug Guide: Order Araneae – Spiders (thorough overview, links to details.)
• A Key to Spider Families (Keys, with diagrams of anatomical features.)

Of course I also have a couple of printed field guides. I’m eager for the spring thaw and an opportunity to go chase spiders.

See? This is why we don’t invite mygalomorphs and scolopendrids to any of our parties. They tend to eviscerate and decapitate and consume innocent visitors and splatter fluids all over everything. The Araneomorphae are much tidier, wrapping up their victims in silk and then neatly puncturing them and sucking out their guts. It’s the difference between an axe murderer and the gangster who lays down plastic before executing his enemy. Who would you rather have at a social event?

No one is surprised, instead all the arachnologists are thinking “Cool!” Scientists in the Amazon captured a video of a mygalomorph spider chowing down on a young mammal. Mygalomorphs (tarantulas, funnel web spiders, trap door spiders) are big arthropods that will kill and eat anything about their size that they can ambush, so they’ll eat other arthropods, small birds, reptiles, and yes, mammals.