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Endemic Insects of the Great Sand Dunes
Endemic species are those that exist at only one location or area on
Earth. They tend to be more numerous in habitats that are distinctly different
from the surrounding areas. The Great Sand Dunes harbor at least seven
endemic species of insects. Many of the insects here are `sand obligates',
meaning that they are adapted uniquely for sandy habitats. Currently,
just over 1,000 different kinds of arthropods (insects and spiders) are
known to live at the Great Sand Dunes. However, this may represent only
about 25% of the total number of arthropods that may exist here.
 The
Great Sand Dunes Tiger Beetle
Cicindela theatina
The Tiger Beetle is a predatory beetle which is encountered in sparsely
vegetated sandy habitats which are beginning to stabilize as successional
species like blowout grass (Redfieldia flexuosa) and scurf pea
(Psoralea lanceolatum) become established. Both the adults and
larvae are predatory; the adults are active foragers on the sand, while
the larvae are sedentary ambush predators. Both larvae and adults will
prey on a variety of arthropods including ants, other small beetles, and
mites crawling on the sand surface. They will even scavenge on dead insects,
as long as they are not dried out.
Tiger Beetles are about 1/2" (13mm) long and are named for their
distinctive coloring.
 Darkling
or Circus Beetle
Eleodes hirtipennis
Circus beetles are 1/2"- 3/4" (1-2 cm) long. They are scavengers
in sandy habitats with sparse vegetation. Look carefully, however; another
species of Eleodes lives here which looks similar and is more widespread.
The endemic Circus beetle's specific name, hirtipennis, means
"hairy wings". If you find a beetle that appears to be the endemic
one, look carefully at its back. If there is `fuzz' on its back, you're
observing one of endemic circus beetles.
Circus beetles are named for the posture they adopt when feeling threatened.
If attacked, a circus beetle lifts its abdomen so that it appears to be
standing on its head, and releases a smelly chemical in the intruder's
face. Some people call them `stink beetles'.
Werner's Ant-like Flower Beetle
Amblyderus werneri
This very tiny, light yellowish-brown beetle is truly minute--it's not
much larger than the period at the end of this sentence. It is a scavenger,
and prefers the same type of sandy, lightly vegetated habitat that the
tiger beetle and the circus beetle do. Although this very small creature
is not well understood, its method of foraging is curious. Ant-like flower
beetles apparently feed on dead insect parts which have been blown into
small depressions in the sand. The beetle allows itself to be blown into
the depressions and actively forages on the debris.
Triplehorn's Ant-like Flower Beetle, Amblyderus triplehorni, is
also a very tiny beetle which looks similar to the Werner's ant-like flower
beetle, but is slightly larger. It prefers only the most barren dunes.
It is also a scavenger, and its method of foraging is similar to that
of Werner's. It is easily observed on the bare dune ridges as one approaches
the high dunes.
Hister Beetle
Hypocaccus
(undescribed species)
Tiny, shining black, and globe-shaped, hister beetles are found in the
grassy margins of the sand dunes. The adults are scavengers, while the
larvae (caterpillars) are predatory, probably preying on weevils (Curculionidae),
scarab beetles (Scarab-aeidae), and fly larvae that they find feeding
on decaying grasses and other non-woody plants.
Noctuid Moth, Copablepharon
(undescribed species)
Not much is known about this particular moth. Although it is a noctuid
moth, it lacks the rather drab grey-brown appearance of its cousins, the
"Miller Moths" or "Cutworm Moths". Rather, this species
of noctuid moth is a soft, very pale yellow color. Its wingspan measures
about 1.5" (3.5 cm). Adults can be found in the sparsely vegetated
and grassy margins of the dunes during the daytime, and will come to lights
at night.
Robber Fly, Proctacanthus
(undescribed species)
This insect has been found in the Great Sand Dunes and surrounding habitat.
It is one of the largest insects documented from the area, measuring nearly
1" (2.5 cm) in length. Robber Flies do not seem to have a preference
for a particular type of sandy habitat; they have been encountered in
sand/grass, sand/shrub, and even bare sand environments. Robber flies
are often observed foraging on other flying insects (wasps, bees, and
flies) during the heat of the day, after all crawling insects have taken
cover from the extreme heat of the sand.
 Giant
Sand Treader Camel Cricket
Daihinibaenetes giganteus
Perhaps Great Sand Dunes' best known insect, the Giant Sand Treader Camel
Cricket is not endemic to the dunes, although it was originally
thought to be. The sand treader camel cricket was originally described
from the Great Sand Dunes National Monument in 1962, but recently was
found to inhabit other sandy ecosystems in eastern Colorado, New Mexico,
and Utah. It is about 1.5" (4 cm) long.
 Sand
treader camel crickets are omnivorous. They begin foraging at dusk and
have been observed to feed on dead and live plant material, insects, and
mammal fecal material. They are fossorial (burrow-digging) insects. Their
large hind legs sport horny growths called `sand baskets' that help them
to push sand out of burrows. Males may build a burrow in the evening,
and are known to have `harems' of females. The male's burrow will be visited
by several females over the course of the night, and the male, too, will
visit other burrows during the course of an evening.
Insects and Arthropods
Insects are part of a larger group of animals called arthropods. Spiders,
centipedes, and crustaceans are among other types of arthropods . Common
characteristics include an exoskeleton, segmented bodies, and many jointed
legs.
Although mostly unnoticed, insects and arthropods can be found in every
habitat type on Earth, including the arctic and antarctic areas--even
associated with floating mats of algae in the sea! Entomologists (scientists
who study insects and arthropods) estimate there are 3 to 30 million different
species of insects on the planet, although only about 1 million have been
described. In Colorado, about three formerly unknown species are discovered
each year.
Insects and arthropods play a critical role in maintaining our planet
as good habitat for all plants and animals, including humans.
What do they give us, beside the occasional bite or sting? Here's a sampling:
many fruit, vegetable, and flower crops are pollinated by insects, including
alfalfa, which is very important in the production of beef, pork, mutton,
and wool. Silk, honey, and beeswax are direct products of insects, and
our most fertile soils are constantly tilled and fertilized by arthropods
of many types. Waste products ranging from banana peels to wood scraps
are gradually broken down and returned to the earth--by insects. They
are critical food sources for many fish, birds, reptiles, amphibians,
and mammals, including humans in some places. Insects have aided scientists
in researching problems of heredity, evolution, sociology, and stream
pollution. Engineers have used insect behavior, structure, and bioproducts
like pheromones, webbing, venoms, toxins, and hives in engineering agricultural
services. They even have aesthetic value for artists, collectors, and
designers.
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