"White dune landscape, White Sands National Monument, 2016." by U.S. National Park Service , public domain
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Brochure about Common Arachnids of White Sands National Park (NP) in New Mexico. Published by the National Park Service (NPS).
covered parks
White Sands
National Park Service
Department of the Interior
White Sands National Monument
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Common Arachnids of White Sands
T
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here are over 500 different species of invertebrates that live at White Sands.
Though rarely seen during the day, sometimes their tracks and burrows are
evidence of their activity in the sand. While most arachnids do bite or sting, most
of those at White Sands have weak venom and are not life threatening to humans.
Remember though, White Sands is their home and you are just a guest.
Wind scorpion
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Eremobates spp.
Sand scorpion
Paruroctonus utahensis
Tarantula
Aphonopelma spp.
This arthropod goes by many different
names including the wind scorpion,
camel spider, sun spider, and solpugid.
They are not dangerous to humans and
have no venom. Not especially large
creatures, the biggest ones have a leg
span of only a couple inches. They are
very fast and active nocturnal predators,
running rapidly over the ground at night
in search of prey. The first pair of
leg-like appendages are not actually
legs but pedipalps with five segments
each. These appendages function
partly as sense organs, like insects’
antennae. They also assist in feeding
and fighting. They have large pinching
mouthparts called chelicerae they use
to overpower and chew prey.
Scorpions, like their spider relatives, have
eight legs. However, they additionally
have greatly enlarged pedipalps attached
to the head, in the form of appendages,
with large pinchers used for grasping
prey. They also have a characteristic long
tail or telson, with a single large stinger
at the end. Scorpions use their pinchers
to grasp other invertebrates, and then
use the stinger at the end of the tail to
inject venom into their prey. They chew
their prey with mouthparts, or chelicerae,
equivalent to the fangs of spiders.
Some scorpions have powerful
venom that is dangerous to humans.
However, like all the scorpions that
live at White Sands, the sand scorpion
has mild venom and is not dangerous.
The sting is painful, similar to a bee
sting. Sand scorpions live in burrows
they dig in the sand, and they come to
the surface at night to search for prey.
The sand scorpion lives on sandy soils
throughout the Southwest.
These large, hairy spiders can be six inches
across with their legs fully extended. Their
bite is not dangerous to humans but can be
painful and may cause an allergic reaction
in some people. Tarantulas make their
homes in burrows and crevices. They will
lay in wait and ambush instead of using a
web to ensnare their prey. Anything that
the tarantula can subdue is a potential
meal, including insects, small rodents, and
reptiles. The tarantula’s mouth acts
like a tube that sucks up liquids. They
coat their food in digestive fluids to
predigest it outside of the body before
they eat. Tarantulas have terrible
eyesight and rely mostly on their sense
of touch to perceive the world around
them. Male tarantulas can be seen in
the evenings after summer rains going
in search of female tarantulas.
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Western black widow spider
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Latrodectus hesperus
Funnel-web spider
Agelenopsis longistylus
Apache jumping spider
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Geolycosa rafaelana
Burrowing wolf spider
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Latrodectus mactans
Sand wolf spider
Arctosa littoralis
The female black widow is all black with a
distinct hourglass mark on the bottom of
her abdomen. Females are about as big as
a quarter, and males are less than half that
size. The male widow is a brown-yellow
color with a yellow hour glass mark and
white strips along his abdomen. Adolescent
females have the same markings and color
as adult males. These spiders live in dark,
damp places like the thatch at the bases of
yucca plants and old rodent burrows.
They only bite when disturbed and are
generally not lethal to healthy adults.
When mating the male spider wraps
the female in a thin layer of silk. If he
cannot get away fast enough after he is
finished, the female may eat him. In the
summer, females can lay four to nine egg
sacs, each filled with hundreds of eggs.
Funnel-web spiders build flat-spreading
webs close to the ground that have a
descending cylinder (funnel) near the
center or on one side, which leads down
into a dark retreat. The webs have two
layers, a thicker, base layer that supports
the entire web, and a thinner, upper layer
which transmits the vibrations of insects
that fall onto the web to the spider, who
resides inside the funnel entrance. When
the spider detects the vibration of an
insect or other small arthropod, it
will run out on the web to the insect,
tackle it, bite it, and drag it into the
funnel to feed on. These spiders have
mild venom, are not dangerous to
humans, and should not be confused
with the unrelated and dangerous
“funnel-web” spiders of Australia.
As their name implies, jumping spiders
are avid jumpers. They hunt and
behave much like cats, watching for
invertebrates equal or smaller in size.
They then pounce on, subdue, and eat
them. Jumping spiders are ambush or
sit-and-wait predators. Unlike other
spiders, they roam around on vegetation
and do not build webs to capture prey.
Jumping spiders have excellent vision,
and they can jump several inches to
capture prey. They also have elaborate
courtship displays, where males court
females by dancing and displaying
iridescent blue-green markings
on the fronts of their fangs. The
Apache jumping spider is widespread
throughout the Southwest and much
of the southern United States and into
Mexico.
Burrowing wolf spiders are medium- to
large-sized spiders that construct and
live in silk-lined burrows. These spiders
tend to spend the daytime at the bottom
of the burrows and come up to the top
at night, similar to tarantulas. They have
very sensitive touch senses and feel the
vibrations of passing insects and other
spiders from their burrows. Once they
feel the vibrations they will ambush and
attack their prey, pull them down into
their burrows, and feed on them. The
openings of the silk lined burrows,
with a similar circumference to your
finger, can be seen during the day
and are common at White Sands.
Other species of free roaming wolf
spiders look similar to the sand wolf
spider, but they tend to be lighter and
camoflauge on the sand surface.
The sand wolf spider, also called the
beach wolf spider, lives in open sandy
habitats such as at White Sands. These
spiders do not build webs and are
free ranging predators that run over
the ground surface in search of small
invertebrate prey. Their coloration is
variable so that they are camouflaged to
the particular type of sandy backgrounds
that they live on. Those at White Sands
tend to be much lighter in color than
elsewhere. These spiders use their
camouflage to sit and wait on the open
sand for smaller passing invertebrates
that they then chase down and
consume. Sand wolf spiders have mild
venom and are harmless to humans.
These spiders inhabit sand dunes and
sandy beaches throughout the United
States and Mexico.
To learn more about White Sands, visit http://www.nps.gov/whsa
Updated 01/07/2016