I'm fairly new to the area, and actually to the US. I'm interested in finding local species in fairly decent numbers which will allow me doing some research. I live in the Las Vegas area, and wondered whether I could get some information regarding the following:
1. What are the most prevelant species around here?
2. I assume C. exilicauda do not burrow, and therefore what would be the best way capturing them? I did go to the field twice, both day (turning rocks) and night (UV) with bery limited success.
3. As for burrowing species- how deep are the burrows, and how can one tell between scorpion burrows and those of other organisms?
4. Do they tend to stay in their shelters in windy days/nights? Is it still too cool for some of them to come out this time of the year.

Thanks for any information

Welcome to the site! Southern Nevada is home to one of my favorite scorpions: Hadrurus spadix. C. exilicauda do not burrow, theyre arboreal (meaning theyre climbers and spend most of their time above the ground). I have found all but a select few in bushes (name unknown). Your best bet is to blacklight for these as theyre a small species and are tan colored, making them hard to find in the daytime. I have also found a few under rocks as well. Most burrowing scorpions do not dig burrows that are horribly deep. Hadrurus spadix is a burrower and I have had mine in captivity dig burrows no deeper than 8-10". They usually stop at that point for some reason. Determining scorpions burrows is a little tricky... they are somewhat easy to distinguish from Theraphosid burrows as there will be no silk lining the entrance for prey detection. I have never observed if scorpions are out on windy days or not. I dont think it would make a difference to be honest. They have been observed to be alot less active when a full moon is out to decrease the risk of predation by owls, bats, etc... If youre in southern Nevada, I would guess the temps to be about 95 in the day by now? Is that correct? If so, you shouldnt have any problem finding scorpions at this time of year. I vacation in southern Arizona each year in early October when the temps are still in the mid to high 90s and scorpions are very active.

Thanks a lot for the info. I was told that C. exilicauda climb vegetation were they sit and wait for their prey, and therefore I thought that wind could interfere with prey detection on the bushes. Anyway, the temperatures have probably been more of a problem, as we've had a somewhat cool weekend, with temps dropping to the low 60's at night. Temps will be in the mid-high 90's this week during the days, but the nights are ~70.

Do H. spadix burrow in rocky or more sandy areas? will they burrow near vegetation, or are they scattered randomly? The depth of the burrows you mention isn't too bad- I used to dig Scorpio maurus burrows up to three times as deep. I guess I'll give digging a shot if my night excursions with the UV flashlight aren't a success.

I wouldn't suggest digging, and i would assume that Hadrurus burrows would be deeper than eight inches. I have heard of other Hadrurus species digging several feet deep. I wouldn't call C. exilicauda arboreal, i believe negageotrophic is the term. Basically meaning they do not specilize in any particular retreat. Sometimes scaling flora for maybe thermoregulation, or prey foraging in particular, or perhaps this may help avoid predation. Or all of the above.
Obviously they cannot retreat in a plant during the day, in the arid summer sun they would simply lose too much moisture. Maybe around the base if their is plenty of cover such as the peeling bark of a juniper, sage, or joshua tree. Other than that rocks that are not partly covered by sedimentary buildup are good places for this species. There are some others around here that have more experiance with physiological/behavioral adaptations in C. exilicauda than i. I work with Chactids and Vaejovidae.

Many times it simply takes time to learn how recognize habitat preferences and signs of inhabitance. I strongly suggest you search for peer reviewed journals and like material. These are the absolute best for scientific topics, and field study as you are speaking of. Are you looking to collect or just observe in the field? Are you working with/for any educational function? (ie thesis, projects, college experiments, surveys, etc)

http://www.science.marshall.edu/fet/euscorpius/
http://www.americanarachnology.org/

Zach

Zach, thats why I mentioned I have found C. exilicauda under rocks too. Most of my observations done in both the day and night I found them up in brush. I only found 3 tiny 2nd instar on the ground under a rock. All the rest were in brush or on walls. In captivity, youd be very hard pressed to find them on the ground. Thats why I consider them arboreal. Of course youll find them on the ground while looking for another hiding place, etc... but once they find it, they spend most of their time above ground. I kept mine with a small horizontal hide at first and he never went under it for more than an hour. I then provided a vertical climbing structure and he has yet to come off of it for more than 5 minutes. In fact, he will wait at the base of the vertical bark and catch crickets as they come by. Its almost like he doesnt ever want to leave that vertical structure.
And the spadix burrow comment was only based on my captive care observations. My spadix will dig several burrows and then stop about 8-10" in. It still has about 2' more to go, but it just wont dig further than that. Perhaps the humidity levels in captivity are more sufficient than in the horribly arid southwest where they may be required to dig several feet down to be comfortable. Just my thoughts.....

I am not familiar with any recent study on habitat preference, and other than "The Biology of Scorpions" there is little helpful information published.
I am currently a postdoc at UNLV, and have done scorpions ecophysiology research in the past (PhD research). In fact, very little has been done in this field since Neil Hadley took another route, much to my advantage...

To be honest, at this stage I'm not interested in one species more than any other. My main interests are water relations and energetics of scorpions, and the important criteria for me at this stage are:

1. How abundant the scorpions are around here, and how easy they are to capture. I need a sample size of a 30-40 at the very least for my experiemntal purposes. This usually didn't take me more than 6 hours (together with a friend/my wife) when capturing Leiurus quinquestriatus, Buthotus judaicus or Scorpio maurus in the past (in Israel).
Any chance the local populations are as dense?

2. Body size is an issue, as I would like to be able to take repititive hemolymph samples from the same individual. For that purpose I rarely used individuals of less than 1g in mass, and rarely <1.5g.

Based on the above and my location, what species would be my best bet in your opinion. I thought C. exilicauda would be my best bet as they do not burrow and therefore are supposedly easier to capture. However, I found another Buthidae, Buthus occitanus, using abandoned burrows for shelter when I dug for Scorpio maurus.

Hello, Dr....

There are several species in Nevada, this list is from my website and I will try to remember which are actually in Southern Nevada, which will probably be most of them, with $; T means type is from Nevada, E = endemic to Nevada; for localities look them up directly on my website http://angelfire.com/tx4/scorpiones :


Buthidae
Centruroides
$Centruroides exilicauda (Wood)

Iuridae
Anuroctonus
$Anuroctonus phaiodactylus (Wood)

Hadrurus
$Hadrurus arizonensis arizonensis Ewing
$Hadrurus spadix Stahnke

Superstitioniidae
Superstitionia
$Superstitionia donensis Stahnke

Vaejovidae
Paruroctonus
Paruroctonus arenicola arenicola Haradon (TE)
$Paruroctonus becki (Gertsch & Allred) (T)
$Paruroctonus boreus (Girard)
$Paruroctonus luteolus (Gertsch & Soleglad)
Paruroctonus shulovi nevadae Haradon (T)
Paruroctonus simulatus Haradon (T)
Serradigitus
$Serradigitus wupatkiensis (Stahnke)
Smeringurus
$Smeringurus vachoni vachoni (Stahnke)
Vaejovis
$Vaejovis confusus Stahnke
$Vaejovis hirsuticauda Banks
$Vaejovis waeringi Williams (no record in NV... yet)

What is your definition of "southern" Nevada? ie., how far are you willing to travel?

Anywhere you have dunes you will find plentiful scorpions, usually in the genus Paruroctonus, and near LV you should find P. becki in good numbers in hummocks, soft sandy soil, swales, etc. (I have collected these at Cliff Dweller's Lodge, in the AZ strip, type locality is Nevada Test Site).

I'd write more but my son has to get to Baseball practice!

kari

thanks a lot for the list!

As I said, the main criteria at this stage would be availability and body size. I live in Henderson/Las Vegas, and since scorpions accomodate a large chunk of the pest control section in the local Yellow Pages I beieve that I wouldn't have to travel that far to find them. As I said, for my next experiemnt I will settle for the species which is the easiest to capture in large numbers.

I have other plans for future experiments as well, as the other thread I just opened may suggest, but at the moment I need to get some work done quickly!

OK, right...

So, here is what to look for to find numerous specimens of what the pest control people are finding, Centruroides exilicauda, WHICH, by the way, has returned to its old self, Centruroides sculpturatus (I'll be writing an article on that for the next Forum):

Rocks, rocks, rocks. Road Cuts. Canyon Walls (Black Mountains/Boulder/Laughlin area, Red Rock Canyon, etc.). Cow patties, well, in rangeland, not feedyards! Trees, with peelable bark, including palms (especially in the NEW suburbs or old areas near the desert with old trees or palms UV is best for palms), cottonwood groves, ironwood, greasewood, mesquite... Joshua Trees, more rocks, and, perhaps the best, old abandoned buildings in the desert, old fences, old corrals, etc. Anything lying on the ground, junk yards, stables! You get the picture. It is opportunistic.

Negageotropic means they cling to the undersides of things, so be careful how you lift rocks/lumber/bark, etc., that's how the vast majority of stings from all Centruroides species occur. Steve, it's species, singular or plural

Also in the rocks/walls/road cuts department you might run into Serradigitus spp. Little guys that run very fast and any specimen you find might be new, or S. wupatkiensis....

There are likely several new species in Nevada, Dr. Stan Williams (SFSU) is working on that.

I have been really curious if any scorpions are in the pines in the Clark Mountains and other mtns. in S Nevada/Utah, as they are throughout Arizona and New Mexico, where only 3 such species are named out of more than 10 known but undescribed.

Unfortunately, when it comes to American scorpions, body size can be an issue indeed! Centruroides are roughly 1g, a good female up to about 60-65mm, and they are on the medium-large side! Most of the other species max-out around 40-50 mm. Hadrurus, of course, are 100-110 mm, a big gravid female can weigh as much as 32 grams, but they are getting few and far between, especially with all the stinking paperweight collectors!!! You can find a good colony of these or Anuroctonus (to 70 mm) around LV, but damage to a colony is extREMEly difficult from which to recover. Smeringurus vachoni are quite large, to 90 mm or more, and in the rocky habitats described above, and if you go across the border into California and find Smeringurus mesaensis (80-85 mm) in dune areas you will hit the jackpot numbers wise with virtually no way to wipe out a colony.

Now, here's the important part, since you are a scientist as well: I am involved in a major revision of the scorpion family Vaejovidae (plus all American scorpions in the process) and we are in need of live specimens for DNA sequencing. Not to mention the possibilities of new species, new distribution records, etc. Any help you can give us (the AMNH scorpion crowd) would be much appreciated.

OK, if you have any other wquestions don't hesitate to ask any of us who have thus far replied! Steve and Zach are quite familiar with habitats and collecting, too. I know the fauna and habitats, they know the husbandry and habitats!

take care and good luck!
kj

Thanks a lot for the info. I would be delighted to help in any possible way to your work. I already have three scorpions that I keep as pets in the lab, and you can have them anytime you want. I know very little about identification of New World species, so I'll have to take photos and post them later and then you can decide whether you're interested.