Friday, February 2, 2024

Our mygalomorph residents

Uh, what did you just say, Sheryl? Mygalomorph? What the heck is THAT? Well, you're in luck today because I'm going to tell you. The funny-sounding name refers to one of two groups of spiders. Mygalomorphae are large-bodied, long-living spiders, such as tarantulas, purseweb and trapdoor species. The other spider group is called Araneomorphae, which includes nearly all the other "true" spider groups – jumping spiders, wolf spiders, orbweavers and lynx spiders, to name only a few.

Lucky you again – now I'm going to share the four mygalomorph spider species that I've documented in our yard. I've recently spent several hours, researching them so I can better understand their differences myself. 

By the way, we've never met in person, but Dr. Norman Horner and I have been long-distance friends and spider fans since the 1990s. Back then, he was teaching the only arachnology course that I knew of in Texas at Midwestern State University. My secret aspiration was to attend it someday. Instead, I taught myself the little bit I know about spiders. But I digress. Dr. Horner has since retired and is now a professor emeritus of biology (and the former director of MSU’s Natural Laboratories). I emailed him for his opinion on my mygalomorphs. Here are parts of his reply: "...Congratulations on finding female trap doors in your yard! The females usually stay close to home and you have to dig them out! Congratulations, that does not commonly happen.

"Checking distribution records, yes, it is possible for you to have all of these species in your yard. I would think there would be too much competition for them to all be in such a confined space, but all of them are found in Texas.  Literature shows 69 species of Ummidia!"

Comstock's wafer trapdoor spider (Myrmekiaphila comstocki) Wafer-lid trapdoor spider family (Euctenizidae)

Per Common Spiders of North America by Richard A. Bradley, "burrows have been found in areas of thick leaf-litter in the woods.... The burrow has a wafer-think trapdoor. There may be a branch within the burrow that has a second trapdoor."

I found ours in leaf litter beneath one of our live oaks. And I'm guessing the spiderlings I found in 2018 are this species, too.

Ummidia sp., male
Cork-lid trapdoor spider family (Halonoproctidae)

From Common Spiders of North America, "the female is a dark brown or black spider with a round body and short legs. The male is black with longer legs and sometimes with a lighter-colored abdomen.... The burrows of this spider have a hinged, thick cork-type trapdoor. When closed, the burrow and its doors are well camouflaged and difficult to detect." 

We have found this trapdoor in our gardens twice: here and here.

Ummidia sp., female

Southwestern trapdoor spider (Eucteniza relata), female  
Wafer-lid trapdoor spider family (Euctenizidae)

Per Bugguide.net, "they form burrows usually closed with a trapdoor. Webs are used to line the burrow and form a hinge for the trapdoor."

I found the beautiful girl above in 2008. 

Southwestern trapdoor spider (Eucteniza relata), male

Euagrus chisoseus
Funnelweb spider family (Euagridae)

This spider has long spinnerets that are held in an upward, curved position. Per Spiders of North America, "the web consists of fine but tough sheets with several funnel-shaped openings mostly hidden under a rock, log or other debris. Some of the sheets and funnel webbing may extend well out into the open. The spider usually remains in the retreat but may rest near the mouth of a funnel at night."

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