Transcript S. mesaensis - Our Research

Arizona/Nevada, April 16-22, 2008
REVSYS volunteer Zach Valois
(undergraduate, Salt Lake
Community College) and friend
Kelsey Neeley traveled over 2,200
miles in an attempt to collect five
major target species of scorpions for
the REVSYS project. We collected 8+
species, representing five genera. A
total of 70+ specimens were collected
and deposited in the AMNH collection.
We worked in several different biotic
communities and desert ecosystems.
From Western Colorado Plateau
highlands, to lower Sonoran
desertscrub. Partially funded by the
REVSYS NSF grant, this trip was
successful and yielded some great
finds; including Paruroctonus
ammonastes, new localities of
members of Vaejovis from the Vorhesi
group, and topotypes of Smeringurus
mesaensis.
Participants:
Zachary J. Valois
Kelsey Neeley
SLCC
Upper Sonoran desert of Maricopa County ascending into chaparral,
elevation around 4500 ft. Habitat of Vaejovis spinigerus, Centruroides
sculpturatus, and Aphonopelma cf. chalcodes.
Forest road leading into the high pine and manzanita forests. Notice the difference in
vegetation of the north facing (right) and south facing slopes (left). It would be interesting to
take a detailed look at the differences in invertebrate species composition and density within
two slopes. Presumably, overall invertebrate fauna would be more successful on the north facing
slopes. Where as you can see, vegetation is thicker and more speciose than the drier south facing
slope.
Adult Aphonopelma cf. chalcodes female.
Almost three hours of off-road
driving took us to the ridge of the
Mazatzal Mountains. Beautiful
pine forest around 7000 ft. The photo
on the bottom left is the trail that we
were forced to drive up in order to
leave the location during the previous
trip while collecting in this region.
We were very lucky to get out with
minimal damage.
A female (left) and male
(right) Vaejovis sp., in the
vorhiesi group, individuals
were found within a couple
yards of the opening of a
mine.
Gila County
We came across some interesting bats in this mine, picture here is Lasiurus zanthinus. Bottom left: Female Vaejovis sp. found about 80 ft. from
the mine entrance. Bottom right: A new dwarf theraphosid species from this region seems to aggregate in these open rocky patches surrounded by
Yucca and Manzanita. This burrow placement makes excavation incredibly difficult and may be an adaptation to avoid predation and competition
from other fossorial Aranae. The choice of microhabitat may also be an adaptation to avoid spring snow melt runoff, as the rocks and plant roots
between the rocks may add structure and stability to the soil.
Maricopa County
Typical Sonoran Desert, descending from the pine forests. These lower areas provide alluvial fans and washes
that provide great habitat for Hadrurus arizonensis. Vaejovis confusus, Vaejovis spinigerus, and Centruroides
sculpturatus also inhabit this zone.
Horned lizard (Phrynosoma sp.)
Maricopa County
The upper chaparral riparian habitat pictured above yielded extremely high numbers of Centruroides sculpturatus-in addition to a lot of hungry
mosquitos. The old highway that runs along Sycamore Creek has been shut down and blocked off, so that meant lots of extra hiking to find a spot
in which we could climb down the rock walls into the creek. We ended up hiking about five miles up and down the creek. Below pictured is a
Centruroides sculpturatus female.
Vaejovis sp. vorhiesi group.
Vaejovis spinigerus.
The overlook into the creek, about 80 feet down.
A Centruroides sculpturatus female that
has captured a moth.
Adult female Vaejovis spinigeris.
On the north end of Mesa, we picked up topotype specimens of Smeringurus mesaensis. Unique lower Sonoran desert and
grassland. Sandy ridgelines deposited by the flow of the Salt River provided ideal habitat for S. mesaensis, in addition to
Hadrurus arizonensis, Vaejovis spinigerus and Vaejovis confusus. Although with exception to S. mesaensis, these species
were found more abundant in harder packed, rockier areas. This could simply be a result of exploitation competition among
the scorpion guild. S. mesaensis seems to simply dominate these soft, sandy areas.
In areas with creosote, S. mesaensis almost always
occupied a burrow at the base of a bush.
Adult female Smeringurus mesaensis.
Adult female H. arizonensis.
An adult S. mesaensis eating, these were commonly seen
being preyed upon.
Sub-adult female S. mesaensis feeding on a weevil
S. mesaensis. The burrow of this individual is located directly at the
base of the bush.
S. mesaensis burrows.
Mohave County
Heading north-west we begin to enter the Mojave-Sonoran desertscrub transition. Occasional patches of isolated dunes were of particular interest,
concerning our target for this region. Only one area along the east bank of the Colorado River did we find the elusive scorpion, Paruroctonus
ammonastes. S. mesaensis was extremely abundant in every area that had even remotely soft substratum. The combined activity of ATV and OHV
use and urban sprawl seem to only provide better conditions for S. mesaensis. S. mesaensis being an already highly predacious, successful
medium sized scorpion thrives in disturbed areas. V. confusus and H. arizonensis are found in the sandy habitat, but are of higher density in
rockier areas, such as this wash pictured in the bottom right photo. There is likely some Serradigitus species in these rocky foothills.
Zach sorting and preserving specimens.
Adult male Vaejovis confusus.
Adult female Paruroctonus ammonastes.
Keying specimens in the field.
Adult female S. mesaensis.
Adult female P. ammonastes.
Female Vaejovis confusus.
A third instar male Smeringurus mesaensis.
Male Serradigitus wupatkiensis.
With a slight rise in elevation and latitude, the
vegetation of these arid footslopes begin to
change. Compare the dominating sage and yucca
basin in this photo with the that on the open scrub
in top left photo.
Male Hadrurus arizonensis.
We give special thanks to Lorenzo Prendini, Jeremy Huff, David Sissom, Warren Savary,
Christian Elowsky, Joe Bigelow, Darrin Vernier, the Salt River Pima-Maricopa Indian
Community and their Police Department, Kelsey Neeley, and foremost Kari McWest .