Photo Essay
Invertebrates of the Shallow Soil habitat
Despite many miles of identical habitat there is an amazing diversity of invertebrates in the Shallow Soil habitat. Members of the 2008 class of the Llano Estacado chapter of the Texas Master Naturalist ventured out on a private ranch during November and spent a day photographing what could be found. The Sibley Nature Center's executive director later met seven classes of elementary students in Fort Stockton and spent another day investigating the habitat. The two places examined were 60 miles apart, and a few differences were noted (and are indicated in the text below).
Related photo essay: Plants and Animals of the Shallow Soil Habitat
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One of the most common insects (other than grasshoppers) were saltmarsh moth caterpillars.
The saltmarsh caterpillars have a variety of color forms. They often feed on species of amaranth and chenopod (goosefoot or lambsquarters), but investigate everything in their path. Individual tumbleweeds will often have several caterpillars.
Finding a large hornworm ( the caterpillar to one of several possible sphinx moths) was a surprise to see plodding along on almost open ground. It might have been infected by a parasite that also uses a bird or an animal for a host, but that is unknown.
A dogface butterfly caterpillar was found not far from its doveweed food source.
This might be a color variant of the dog face butterfly caterpillar, but the Sibley staff was not sure.
A number of orbweaver spiders were found in the creosote bushes and mesquites of the pasture.
A tiny yellow crabspider lurked near a prairie dog hole in a playa surrounded by the creosote bush habitat.
Leaf-footed bugs often plague prickly pear plants, but other plants are investigated, and used for mating behavior.
This small guy may be a "cotton stainer," a long way from any cotton.
A striking longhorned beetle, whose larvae bore into the wood of trees and shrubs was caught by the Fort Stockton children. Despite some investigation of Bugguide, Sibley staff was unable to identify the species (and thereby learn its preferred host plant.)
One of the biggest surprises was this giant striped weevil.
Most weevils (and there are many species) are very small. Most weevils feed on seeds.
The darkling beetles are common in the habitat. They feed on detritus on the desert floor.
Soldier beetles are often found on the blooms of plants. For some reason, this one was walking instead of flying.
Dung beetles are important, and are a sign that the rancher does not use pesticides on his rangeland.
This warty-shelled beetle remained unidentified.
Boatback beetles hunt small snails.
Ladybird beetles (ladybugs) are an unusual sight in the fall. This one rested on a Johnson grass blade in a low spot along a road.
This unknown beetle appeared to be laying eggs in the soil.
Robberflies are common predators of all habitats, but no guides have been published to determine what species live in west Texas habitats.
The tail of this robberfly was different - was it a different species, or just the opposite sex?
Paper wasps will build nests on the underneath side of broomweeds, such as these are feeding on.
The Fort Stockton children caught an ichneumon wasp - who parasitizes caterpillars with its eggs.
A small Pepsis wasp paralyzed and drug a wolf spider, and ten feet away, another Pepsis wasp was dragging another wolf spider. To see two successful hunts so close was very unusual.
Millipedes normally emerge from Aphanogaster ant nests after a rain to feed on rotting vegetation, but they also will feed on ephedra (popotillo, or Mormon tea) to harvest the silica in the plant's stem, which is needed for the strength of the their exoskeletons.
Bristletails (firebrats) may be common, but the staff at Sibley had never seen any before the two field trips. Attendees of both field trips caught bristletails in the morning, but not in the afternoon.
Unlike their close kin the silverfish, bristletails can jump. They also feed on rotting vegetation.
A tiny midge (fly) causes the creosote gall to form.
One of the class members of the 2009 class later identified these strange white protuberances on a mesquite to be a variety of mealybug. We think she is correct.
Cow killers (velvet ants) are the wingless females of a species of wasp. The male has wings. The female lays her eggs in grasshopper egg clutches. Several species are common in the habitat.
A red jumping spider might be a mimic of the cowkiller - its red color and the shape of the color might make a predator think twice about grabbing it for a meal.
If you look very close among the gravel you will spot over 35 tiny dots, all of which are tiny false chinch bugs. Over 50,000 covered an area of 1000 square feet, but not another one was found in over 15 hours of observation in the habitat. Why was the swarm in one place and not any other?
Aphanogaster ants swarmed coyote dung, tearing it apart to carry underground.
The Sibley staff could not agree on which species of sulfur butterfly sat on a perezia.
A sleepy orange butterfly warmed itself on the ground.
Again, the Sibley staff could not agree on the species of this butterfly.
Here it is again, with wings closed.
Was this a checkered white, or?
A cloudless sulfur stayed close to the ground. Were all the butterflies low to the ground because of the temperature, or was it part of their evasion tactics in response to the presence of the people?
One of several possible species of katydid clambered around in the grass among the creosote.
Sibley staff believe this to be Clematodes larrea, the creosote bush grasshopper, one of several species of insects that have adapted to living on creosote bush, despite its complicated chemistry that prevents most insects from indulging in a meal of creosote bush leaves. It was found at Fort Stockton, but not at the ranch 60 miles to the northeast.
Between the two groups of people observing the habitat, at least twelve possible species of grasshopper was found. This one is believed by the Sibley staff to be a Russian Thistle grasshopper
Despite there being a group of grasshoppers called toad lubbers for their resemblance to toads, the Sibley staff could not find any species with a grouping of blue dots on its back.
This grasshopper had banded wings, and bright blue legs.
Some grasshoppers have a slant face and have stripes. These feed on grasses where they are well camouflaged, and they rarely land on the ground.
Several species of bandwinged grasshoppers were seen, but sexes can have different appearances. After trying to figure out what was what, the Sibley staff gave up after an hour of puzzling. The bandwings usually land on the ground, where there speckled appearance makes them disappear.
Was this another species of bandwing?
Tarbrush Grasshoppers (Lignrotettix planum) were plentiful. Scientists have studied their "aggressive signalling," where males will have " acoustic duet duels" that settle an argument over a mate without physical force 80 percent of the time.
The snakeweed grasshopper prefers to eat broomweed.
Was this a mating pair of snakeweed grasshoppers?
We also found Hesperotettix speciousus, a neon green grasshopper, feeding on the tarbrush interspersed with among the creosote bush.
This large grasshopper with red legs and markings on its abdomen, might have been an immature lubber grasshopper, but we could not find any grasshopper on our internet resources with so much red on its body.
Oh my! Another bandwing? So confusing!
After we collect hundreds of photographs of grasshoppers in the region, we hope to be able to convince a grasshopper specialist to help us accurately identify the species found in the region. After surveying a number of texts and websites, we believe around 100 species of grasshoppers may be found in the region.
Yet another bandwing? Or, not?
What ate this bandwing grasshopper? A grasshopper mouse? A bird? A lizard? A box turtle? Whatever it was, it only wanted the juicy abdomen!
The redwinged cracker, Arphia pseudonietiana, was only found at Fort Stockton, but the species has been seen in every habitat of the region. When it flies, the wings are bright red. When it flies, it crepitates, making a clicking whir as it goes.