Tips For Identifying Herps, Arachnids, & Myriapods in Arizona

Background Info
Later this month, I’m going to be visiting the hot state of Arizona. As the title suggests, I’d like to know any tips or advice for finding and identifying herps, arachnids, and myriapods on the spot, preferably without the use of online identifiers. My main goal is to be able to identify the most commonly encountered species and their look-alikes.

What I Need Help With
I’m good at identifying their snakes, but I don’t think I could identify most of their lizards (all of their spiny lizards, whiptails, and horned lizards look almost identical to me). I haven’t yet figured out their frogs either. In terms of arachnids, I’m trying to find scorpions, solpugids, and spiders (specifically tarantulas). I can ID the top three most common scorpions, but I’m stuck when it comes to any tarantula or solpugid. I can only identify a handful of myriapods.

I apologize if this topic is too vague, as this is my first post on this forum. If there’s anyone that can share their tips, it would be greatly appreciated!


Welcome to the forum!

The best resource for identifying Arizona’s herps is probably the 2022 2nd edition of “A Field Guide to Amphibians and Reptiles in Arizona” by Holycross, Brennan, and Babb.

Hopefully someone else can help with arachnids and myriapods.


To identify to species and even genus, many arachnids require the use of detailed keys published in obscure journals and microscopic observation (or at least knowledge of morphological jargon in addition to the keys). I’m not aware of any field guides to arachnid groups like we have for vertebrate groups that include every species. There’s just too much diversity and too little interest. Field guides that include arachnids just include the commonly encountered species–here’s your options. Out of curiosity, why do you need to identify them on the spot?

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Yeah highly recommend the new herp book. It’s about $25 as I recall. Worth the price

Thank you for the replies! Are there printable guides online that I can use?

I don’t need to identify them on the spot, but I’d definitely prefer it so I’d have background knowledge on the species.

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For scorpions, solpugids, and tarantulas, their ecology and behaviors are all fairly similar within each group–so identifying them to species in the field wouldn’t really help you get to know them in any greater detail than at group level. My recommendation is to just enjoy searching for them (portable black light and headlamp), looking for any interesting behaviors, and photographing them (in as much detail as possible to get IDs after you post the observations). Learn by observing is my mantra.


Thank you for the recommendation! I’ll be sure to do that.

For many arthropods, iNaturalist itself might be the best online reference to help ID what you observe, by reviewing mapped Research Grade records from the area you are visiting.

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Hi rinaturalist, much of what I contribute to iNaturalist are scorpions of the United States and I am based in southern Arizona. I have close to 40 species of scorpions from Arizona on iNaturalist (azgulo). Unfortunately there does not yet exist any physical field guide to this group, but there are at least a few in the works that I am aware of. Hopefully my contributions to iNaturalist can serve as something of a guide. There are many lookalikes (e.g. Vaejovis, Pseudouroctonus, etc) that are best identified by their restricted sky island ranges, as they differ very little morphologically. I try and get to the IDs regularly, but you can tag me to get my attention too. Hope this helps a little.


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