Arthropods other than insects

A page started October 2020, for non-insect arthropods, and so far growing very slowly. It's organized alphabetically by selected taxonomic levels.


Please don't take my IDs as authoritative. These pages of nature photos represent one person's voyage of discovery, not the studies of a trained expert. If you see something I've misidentified, please contact me via my "Contact" page, which is tabbed at the top.


Arachnida: Spiders and their Allies


Achariformes, Eriophyidae: Poison Ivy Gall Mite (Aculops Rhois)

These mites colonize Toxicodendron species including poison ivy, but also species of Rhus (the picture shows them on R. trilobata). Both those genera are in the sumac family.


Achariformes, Eriophyidae: Purple Erineum Maple Mite (Eriophyes calcercis)

Achariformes, Eriophyidae: Phyllocoptes populi



The aspen leaf galls caused by this mite are yellowish and convex when seen from the upper side of the leaf. Seen from the bottom of the leaf, the galls are convex and have something indistinct in them (see the thumbnail to the left). That something includes microscopic mites. If the bulge on top of the leaf is less pronounced, the mite responsible may instead be Aceria varia.


Araneae, Araneidae: Black and Yellow Argiope (Argiope aurantia)

The Araneidae, or Orb Weavers, are known for creating large, careful spiral webs. One of my photos shows a stabilimentum, or ladder-like addition to the web. The function or functions of stabilimenta are still being debated. Black and yellow argiopes are a common spider on most of the North American continent and are known by a variety of other names.


Araneae, Salticidae: Jumping Spider (Phidippus)

As you might guess from the name, jumping spiders don't rely on webs to capture prey. Instead they're ambush predators. In this photo, a jumping spider (exact species unknown) is grasping its victim, probably a honeybee.


Araneae, Salticidae: Red-Backed Jumping Spider (Phidippus johnsoni)

In September 2021 I found a female jumping spider trapped in my rain gauge. Two of my photos of her include my fingers, providing a sense of how small these spiders are.


Araneae, Tetragnathidae (Long-Jawed Orb Weavers): Tetragnatha


Araneae, Theraphosidae (Tarantulas): Aphonopelma

In a half-century living in the Southwest, I've only seen tarantulas in the wild three times. The third time, I  had a camera handy. This tarantula has lost one of its lets.


Araneae, Theridiidae: Western Black Widow (Latrodectus hesperus)

August 2021: as I pulled an empty propane tank out from under my gas grill, I saw a spider about three inches from my hand. I took a few pictures, went online, and realized I'd had a close encounter with a black widow. I'd known about the all-black ones, with red hourglasses on their bellies, all my life. I hadn't known that immature black widows look very different from the adult females. I'm now more careful when reaching under the grill.


September 2021: I saw a spider on the wall of my house and grabbed my camera. The picture is grainy because of the low light. This time it was a male (they're much smaller than the females).  The black knobs at the front of the male are called pedipalps.


September 2022: I found an apparently dead adult female just inside my front door, where my wife had just sprayed some insecticide (I'm glad to say that she doesn't use that stuff outside).  I thought about posing the spider in the palm of my hand (no danger if it was dead, right?), but my brain took over from my Y chromosome and I collected it in a plastic jar. As I was taking photos, the "dead" black widow came back to life and started crawling around. Yikes!


The Theridiidae are also known as the tangle-web spiders. That name doesn't adequately describe their range of spiderwebs but if you do find one that looks disorganized, be on the alert for black widows.


Araneae, Thomisidae(?): Crab Spiders

Some spiders in families other than Thomisidae are referred to crab spiders, hence the question mark above. So far, both of my photos of crab spiders were inadvertent: I took a picture of something else and the spider happened to be there. Look in the lower right corner of my June 2020 picture for a a green, brown, and off-white crab spider (Mecaphesa). In my August 2021 picture of a marine blue butterfly, a white crab spider is enjoying its meal (a tiny bee or wasp) as the butterfly looks on. That spider might be Misumena vatia.



Decapoda: Crayfish

My only two photos of crayfish tell similar stories. In July 2021, after a bird found a crayfish, dead or alive, it took it to a concrete footbridge over an irrigation canal and ate the innards. It also pooped before flying off. My December 2022 photo is a grainy distant shot—sorry for that. As I watched, a pied-billed grebe came up to the surface of a nature pond with a crayfish, and swallowed it headfirst.


In North America alone there are more than 300 species of crayfish. New Mexico's crayfish include invasive species. I grew up calling them crawfish; you may have grown up calling them crawdads or by some other name. 


Isopoda, Armadillidiidae: pill bugs

Pill bugs, roly polies, woodlice, doodlebugs, potato bugs—and other names, for roughly 270 different species. They're famous for their ability to roll up into a defensive ball, or volvation.


Take a second look at that family name; do you recognize another name in it? The roots of the word "Armadillidiidae" include "Armadillo," "idium" for "diminutive," and "idae" to indicate a biological family (originally referring to offspring).  In other words, a grouping of tiny animals with an armadillo-like special talent.