Range: There are 250 species of glowworm beetles that inhabit the Western Hemisphere. Of these, 23 species occur in the U.S.
In this particular genus there are ten species– of which seven occur in the southwestern (Arizona), central, and eastern United States, and three others occur in Mexico. Two live in Texas.
Conservation Status: No conservation status has been assigned to this poorly studied group of beetles.
Population Threats: There are no specific threats identified for glowworms although, as insects, they are incidentally vulnerable to pesticide use targeted toward other species perceived as pests.
Diet: Larvae, and the larvae-shaped females, are predators found in wet soils. They apparently have a strong preference for millipedes as prey. The short-lived males probably do not feed, but instead metamorphose into adults solely for the purpose of reproducing.
Did You Know?
- Glowworms are relatively uncommon New World beetles occurring from southern Canada to Chile.
- Glowworm females are wingless and resemble their caterpillar-like larvae. Both the females and larvae of most glowworm species glow in the dark, and the eggs and pupae of some species are also reportedly luminescent.
- Male glowworms (pictured) are odd-looking winged beetles much smaller that their mates, and are generally short-lived. They have elaborate, feathery antennae that are used for locating females.
- Luminescent flashes are used to attract mates in fireflies, but the purpose of luminescence in glowworm beetles is unknown. It is hypothesized that it functions in defense, warning potential nocturnal predators that they taste bad—in much the same way that warning coloration advertises the fact that some day-active insects are unpalatable.
Green June Beetle
Range: Eastern U.S. (from New York to Nebraska in the north and from Florida to Texas in the south) and eastern Mexico.
Conservation Status: Not assessed, but likely secure at this time.
Population Threats: This is a species often subjected to heavy pesticide pressure. Furthermore, its close association with the leaf-cutter ant also makes it vulnerable to control measures aimed at leaf-cutters, another perceived plant pest.
Diet: Adult June beetles consume pollen, fruit and the leaves of many trees and shrubs. They are especially attracted to overripe fruits, many of which are of commercial value. Peaches are a particular favorite.
The larvae feed on decaying organic matter in the soil, in well-rotted manure, or in compost piles. These grubs are considered pests because they will also feed on the roots of many plants, some of which are valuable crop varieties.
Did You Know?
- Over a thousand species of true beetles are known to inhabit Travis County. The green June beetle is one of the scarab beetles and is active during daylight hours.
- This species is larger and more robust than its close relative, the common brown May/June beetles. The adult green June beetle usually measures 3/4 to 1 inch in length and about 1/2 inch wide and has dull, metallic green wings. Its sides are gold and the head, legs and underside are very bright shiny green.
- The green June beetle is sometimes mistaken for the Japanese beetle, which is smaller (1/2 inch long) and has copper-colored wings with green margins.
- This species is widely considered to be a plant pest, with adults considered threats to fruit crops and larvae damaging the root systems of both agricultural crops and ornamental plants.
The larvae of the green June beetle are often very abundant in the waste material found in the lower levels of Texas leaf-cutter ant nests. Judging by the number of the larvae found in the ant nests examined, it is possible that these ant nests constitute an important breeding site for the green June bug.
- The grub of this beetle is largely held in control by natural enemies. For example, the female digger wasp will burrow into the larva stage of the beetle and lay her eggs on the grub. The larval wasps will feed on the beetle grub once they hatch, eventually killing the beetle larva. June bug larvae are also fed upon underground by moles, and above-ground (after heavy rains) by many mammal and bird species.
Eastern Fox Squirrel
Range: Found in the eastern two-thirds of Texas and the eastern half of the United States. It also occurs in very limited areas of adjoining Canada and Mexico. Range expansion has occurred in the mid-west and the species has been introduced into many portions of the west: introduced populations exist in California, Oregon, Washington, Idaho, and Montana.
Conservation Status: There is little conservation concern attributed to the eastern fox squirrel because of its wide distribution, large population, and its occurrence in a number of protected areas. In Mexico, it may be considered fragile, but is not officially threatened.
Population threats: Although not considered a major threat at this time, the range of eastern fox squirrels in the eastern United States has been greatly reduced in the past 100 years. Much of its historic habitat is undergoing rapid deforestation and the species is experiencing increasingly restricted distribution due to accelerated residential and agricultural development, and commercial forestry practices.
Another major cause of eastern fox squirrel population decline is mange mite. Severe winter weather can also cause significant short-term population declines.
Diet: Eastern fox squirrel foods include acorns, tree buds, insects, tubers, bulbs, roots, bird eggs, seeds of pines and spring-fruiting trees, and fungi. Agricultural crops such as corn, soybeans, oats, wheat, and fruit are also eaten– which often brings the species into conflict with farming interests.
Did You Know?
- This is the most common squirrel species in Texas.
- Over its large range, the coloration of the fox squirrel varies greatly. The species’ common name comes from its gray and red fur, a pattern that it shares with gray foxes native to Texas.
- Females of this species become sexually mature at ten to eleven months of age. Following a pregnancy of 44 to 45 days, they usually produce their first litter when they are one year old. The average litter size is three, but litter size can vary according to season and food conditions. While most births occur between mid-March and July, some litters may appear as early as late January.
- The eastern gray squirrel is also native to our area, and the two species are very similar in many ways. However, fox squirrels prefer more open habitat whereas gray squirrels prefer good tree cover. Fox squirrels spend more time foraging and running about on the ground than do the grays and may be encountered in fields quite far from any trees, where gray squirrels would not stray.
- Squirrels feed on acorns, which are rich in tannins. Tannins are poisonous to many animals, including some intestinal parasites. Thus, a diet of acorns helps to keep squirrels free of roundworms and tapeworms.
Range: The geographic distribution of the broad-banded copperhead includes western and central Texas, central Oklahoma, and eastern Kansas.
Conservation Status: The broad-banded copperhead is in no danger of extinction or of being endangered. Its population numbers are apparently secure.
Population Threats: The cryptic coloration and stealthy behavior of copperheads has led them to be occasionally found in close association with humans. This usually does not end well for the snake. Despite its shy and secretive demeanor, many people react to these snakes with unwarranted aggression.
Diet: The most common prey of the broad-banded copperhead are small rodents, ground birds, lizards, large insects, cicadas, frogs, toads, and other small snakes. Juveniles feed mostly on large insects and occasionally on small vertebrates.
Did You Know?
- Though only rarely encountered, the broad-banded copperhead is one of three venomous snake species that inhabit the grounds of the Austin Zoo. It has a large head and hinged fangs that spring out when striking at prey or in defense.
- Copperhead bites are uncommon and usually result from the snake being handled or accidentally stepped on. Human mortality rates from the bite of this species are extremely low (0.01%).
- The Broad-Banded Copperhead has elliptical pupils that look like cat’s eyes and, like all pit vipers, has a heat-sensing pit between the nostril and eye on each side of its head.
- This is one of the smaller copperhead species. It grows to only 20-36 inches in length.
- This species bears live young from eggs that hatch within the mother after a 105 to 150 day incubation. Litter size is three to ten young. The newborn snakes are left to fend for themselves and have fully developed senses and venom.
- Young copperheads possess brightly colored yellowish tail tips. The tail tips are held close within striking range and wriggled like a bright caterpillar or worm. This behavior is termed “caudal luring” and is known to attract frogs, lizards, or other prey that the young broad-banded copperhead ambushes to eat.
- The venom of a young copperhead is the same strength as that of the adult.
Greater Anglewing Katydid
Range: Found in southwestern and eastern US, except for most of New England.
Conservation Status: Widely distributed and relatively common, there is no particular conservation status assigned to this species.
Population Threats: Widespread pesticide use can be both a detriment and benefit to this species. Because its population is generally controlled by wasp parasites, the application of pesticides might skew the balance of the relationship between the two species and cause the wasp population to decline more than its prey.
Diet: This species eats the leaves of a variety of trees. It has been found to be common in the citrus groves of Florida, where it only rarely causes major damage.
Did You Know?
- Katydids spend most of their time at the tops of trees where the majority of the leaves are. They can fly short distances when threatened, but prefer to walk and climb. Their flight is primarily a downward flutter. If a katydid lands on the ground, it will typically walk to the nearest tree and climb.
- Throughout much of its range, this species overlaps with the smaller, but very similar, lesser anglewing katydid. Also called the broadwinged katydid, this species is 2 to 2.5 inches long; the lesser anglewing is 1.75 to 2 inches long.
- The greater anglewing produces two calls, one of which is a very distinctive 3 to 5 second series of soft ticks (produced by both sexes) that resembles the sound of two pebbles being rapidly tapped together.
- The eggs of the greater anglewing katydid look like flattened gray oval buttons aligned in two rows along a tree twig or leaf edge. When the eggs hatch, they open like an oyster, separating at the seam along the edge.
- Following breeding season, large numbers of growing katydid nymphs can do severe damage to the foliage of young trees.
- Tiny parasitic wasps play an important role in the natural control of this species’ population. When parasitized, the eggs of the greater anglewing will have a tell-tale flat appearance and round hole from which the wasps emerged. Generally, all the katydid eggs on a single leaf (typically many dozens) will have been parasitized by the wasps.
Range: In eastern North America the wheel bug can be found from Ontario and New York south to Florida, and as far west as Nebraska, Kansas, and Arizona. The range extends into the neotropics (eastern Mexico and Guatemala).
Conservation Status: Widely distributed and relatively common, there is no particular conservation status assigned to this species.
Population threats: Wheel bugs are considered a sign of a healthy, pesticide-free ecosystem because their presence indicates that all the other levels in the food web are intact. The use of pesticides upsets the ecological balance of the landscape, and the wheel bugs disappear.
Diet: Wheel bugs feed primarily upon soft-bodied insects such as caterpillars, Japanese beetles, etc. Because most of their prey items are pests, wheel bugs of all life stages are considered beneficial insects.
Did You Know?
- The wheel bug’s name comes from the prominent semicircular crest on its back that resembles a cogwheel or chicken’s comb. This is the only insect species in the United States with such a toothed crest.
- Wheel Bugs are one of the largest true bugs in existence reaching a length of up to 1 to 1 ½ inches. This species is the largest assassin bug in the US.
- These insects are vicious predators that pierce their food with their beak in order to inject salivary enzymes that dissolve soft tissue. Wheel bug saliva includes a toxic, paralytic substance that immobilizes and kills the prey insect within 15 to 30 seconds of injection. They are one of the few predators that attack the brown marmorated stink bug, a serious introduced pest of both households and many crop plants. They even prey upon other beneficial insects like lady beetles, honey bees and others of their own species.
- Wheel Bugs are not inherently aggressive to non-prey items and will avoid human contact at all costs. However, if pierced by its mouthparts, the resulting wound can be more severe than a bee sting and can have effects that last two weeks or more. Both nymphs and adults should be avoided or handled with caution.
- The wheel bug possesses two scent glands (red-orange in color) that, when disturbed, can be used to emit a repulsive odor. The scent produced by the wheel bug is not as strong as that of the stink bug, but is still strong enough to be detected by humans.
Ruby Crowned Kinglet
Range: The ruby-crowned kinglet occurs throughout North America and can be found in the US, Canada, Mexico and Guatemala.
Conservation Status: This species has a very large range and a population that is believed to be slightly increasing. They are therefore considered a species of little conservation concern.
Population threats: As a species dependent upon insects for its food, large-scale spraying of pesticides would put these birds at risk of exposure.
Diet: Kinglets are insectivores and prefer feeding on small soft-bodied insects such as aphids and springtails. Their prey is generally gleaned from the branches and leaves of trees, although in some circumstances prey may be taken from the leaf litter on the ground or as the kinglet hovers in mid-air.
Did You Know?
- The ruby-crowned kinglet is one of the smallest songbirds on the continent and has a weight just a little more than half that of a chickadee. This species is nonetheless the largest of the kinglet genus (Regulus), which has sometimes been considered a member of the old world warbler family.
- The ruby crown for which the species is named usually stays hidden. This brilliant patch of feathers is only evident on males and is best seen in spring or summer when excited males are singing or defending their territories.
- Some of the tiniest birds in the world have impressively loud voices. The song of the ruby-crowned kinglet would be deafening if these birds were just a little bigger. In early spring, the kinglet’s loud song echoes from the forest edge in the lowlands. By late May, he is singing and nesting at high altitudes in the evergreen forests of the western US and Canada.
- The species constructs its nests up to 100 feet high in the trees. The nests are constructed using an assortment of materials including mosses, grasses, feathers and spiderwebs. Between five to twelve eggs are laid with an incubation period lasting 12-14 days.
- Kinglets are very short-lived birds. As many as 80% of some kinglet species die in their first year of life in the wild, and their maximum lifespan is only six years.
Striped Bark Scorpion
Range: Populations of this scorpion encompass a large geographic range that includes southern Colorado, eastern New Mexico, several of the states in northern Mexico, Texas, western Louisiana, western Arkansas, southern Missouri, Oklahoma, and much of Kansas.
Conservation Status: No special conservation status has been assigned to this species.
Population threats: In Texas, these scorpions have become associated with homes and surrounding areas. Human presence has given them new places to find shelter but these places often place scorpions in conflict with people. While scorpions help to control the local insect population, they are often killed on sight out of fear.
Diet: The striped scorpion is insectivorous, consuming primarily spiders, centipedes, crickets, flies, beetles, and other small insects.
Did You Know?
- The striped bark scorpion can inflict a very sharp, painful sting. Its venom is a mild neurotoxin which is not considered as potent as that of some of its relatives. Some people might have a severe allergic reaction to it, requiring medical attention.
- This is the most common scorpion in the USA. Populations of this species encompass a large geographic range.
- All scorpions are born live in litters that range in size from 13 to 47, averaging about 31. The young climb to the mother’s back after birth and soon molt. After the first molt they disperse to lead independent lives.
- Striped bark scorpions rest under loose bark or in depressions under rocks, logs, and other surface debris during the day, and they emerge after sunset. They frequently climb trees and other plants at night.
- The scorpion stalks its prey mostly at night and depends on its senses of touch and smell. Thess scorpions catch their food by grabbing and crushing them with their powerful pinchers, then bringing their tail over their body and sting the victims. The are paralyzed by the venom and die in the scorpions’ rigid grasp. The scorpions then chew the prey into a semi-liquid state, which they can then suck up with their tiny mouths.
- Striped bark scorpions are active all year in Texas. In Arkansas, this same species are not active on the surface during December, January, February, and March.
Range: Common in the southeastern U.S., this lizard can be found in the eastern third of Texas.
Conservation Status: This green anole occurs in many protected areas (parks, natural areas, etc.). Quite possibly numbering more than a million adult individuals, it is considered to have a stable population with few conservation concerns.
Population threats: In Florida, the species appears to be disappearing where the introduced brown anole has become established. This factor, competition with and predation by other non-native anoles, and human-caused habitat degradation have caused declines in central and southern Florida.
Diet: An anole’s diet consists of small insects such as crickets, grasshoppers, spiders, flies and other arthropods.
Did You Know?
- Because of its ability to change color from green to brown in order to blend with its surroundings, the green anole is sometimes identified in pet stores as the American chameleon. In spite of this ability, this species is not actually a chameleon but is instead rather closely related to iguanas.
- Color changes are not simply a matter of matching background, but also entail body temperature, stress and activity level. Green reflects activity and bright light, whereas brown reflects reduced activity in moist, dark cool conditions.
- An anole’s toes are expanded at the tips to accommodate adhesive toe pads, which aid them in climbing smooth surfaces where claws cannot be used. In contrast, a chameleon’s digits are arranged like mittens, to facilitate their ability to grasp slender branches.
- Both male and female green anoles have pink throat fans (a.k.a. dewlaps), which are used as the means for inter- and intraspecific communication. The much larger dewlap of adult males can often be seen expanding in the direction of females in hopes of attracting them as mates.
- The tail of an adult male anole can comprise 60-70% of its body length.
- Male anoles are strongly territorial. On sighting another male, the anole will compress his body, extend the dewlap, bob his head and attempt to chase the rival away from his territory. If the rival male continues to approach, the two will fight.
Southwestern Trapdoor Spider
Range: Widely distributed throughout the southern half of Texas and northern/central Mexico.
Conservation Status: There are twelve currently recognized trapdoor spider species of this genus, all distributed in Texas and north-central Mexico. Given the anatomical similarities to each other and the challenged posed in studying them, it is likely that more species exist than are currently described. Whenever uniquely-adapted species have very limited distributions, each is inherently vulnerable to environmental changes. Landscape changes, even a local level, can quickly lead to the extinction of these distinctly-evolved forms.
Population threats: Trapdoor spiders favor soils that support lawns. Insecticide and fertilizer treatments of these landscapes can have a negative impact on trapdoor spider populations.
Diet: Trapdoor spiders are opportunistic ambush predators. While they usually prey on arthropods and small insects, they will also take tiny vertebrates– including small frogs. Vibrations warn the spider of any prey and when the prey comes close enough to capture, the spider suddenly pops open the trapdoor and seizes whatever is outside it.
Did You Know?
- Trapdoor spiders create burrows that are lined with a thick silk. The burrows are closed with a heavy cork-like lid, the hinge for which is also formed from the spiders’ webbing. The spiders await passing insects and other arthropods to be preyed upon from behind the “trapdoor.”
- Trapdoor spiders can be longer than one inch in body length (not including the legs), which is quite large among spiders.
- While similar to tarantulas in shape, habit and size, they are only distantly related. They do, however, share a common predator: tarantula hawk wasps, which are known to paralyze tarantulas and other spiders. Observations suggest that, in Texas, female tarantula hawk wasps seek out this species and sting them in their burrows, within which the spiders would remain paralyzed so that they can serve as a source of food for the wasp’s young.
- The preferred habitats for trapdoor spiders are low elevation ecosystems, predominantly desert and tropical dry forest.
- Trapdoor spiders are hard to collect and are, in general, poorly studied. Some species are known only from male specimens.
Range: Dung beetles are found on all continents other than Antarctica. An article published in 2003 listed over 60 species of dung beetles in Texas alone.
Conservation Status: Given the large number of dung beetle species and their anatomical similarities to each other, it is likely that many dung beetle species are evolutionarily unique and have very limited distributions. These conditions would make each individual species inherently vulnerable to environmental changes, such as landscape changes on even a local level.
Population threats: Today’s pastures and rangelands often lack dung beetles, due principally to the use of insecticides and parasiticides.
Diet: Dung beetles feed on feces and often prefer herbivore dung over carnivore dung because it’s packed with more nutrients.
Did You Know?
- The most common of the dung beetles, also known as tumblebugs, are the ball-rollers. These beetles will roll a ball of dung into a hole they have dug for either feeding purposes or to lay an egg inside. This dung ball will get buried in the ground by the beetle and the larva (called grubs) will live its life inside the brood ball feeding on the dung surrounding it until it emerges as a beetle. Both male and female beetles construct the underground tunnels into which they roll the dung balls.
- Dung beetles are very beneficial beetles. They help to put nutrients back into the soil quickly and improve soil structure by aerating it. Getting rid of the dung quickly also reduces the number of flies and other pests. In some parts of Texas, dung beetles remove up to 80 percent of the cattle droppings.
- It has been estimated than an adequate population of dung beetles on pastures throughout the USA could save cattle raisers two billion dollars annually just from increased grazing, improved nitrogen recycling, reduced parasitism and reduced pest flies.
- Most dung beetles have a great sense of smell, which helps them to find fresh dung quickly. Multiple dung beetles will often converge on the same fecal deposit and compete for the fresh excrement.
- According to a 2012 research article, an African species of dung beetle is the only known insect that uses the Milky Way to navigate.
- A dung beetle’s mouthparts are for chewing. Larvae feed on animal excrement buried by the adults. Adult dung beetles have brush-like sieve mouths to help with slurping wet dung.
Texas Ironclad Beetle
Range: Found in the east-central portion of Texas and south into Mexico.
Conservation Status: No special conservation status is designated for this species.
Population threats: While not known to be threatened at this time, this species appears to be dependent upon the dead wood of hardwood trees. Human encroachment and habitat conversion tends to reduce the amount of decaying plant material upon which many species, including this beetle, rely for shelter, nutrition and as egg-laying sites.
Diet: Adult beetles are thought to feed on lichens growing on the trunks of oak trees. Larvae and pupae have been found within the dead wood of pecan trees, which may provide an important food source to the sub-adult life stages of this species.
Did You Know?
- Relatively little is known about this species. Studies have found them associated with pecan, oak and elm trees—including the dead wood of these.
- Adult Texas ironclad beetles can grow to greater than one inch in body length.
- While their mouthparts are designed for chewing, members of this species are not known to damage live plants and are medically harmless.
- This subspecies is named for Horace Haldeman who, in the late 1840s, was one of the first persons to concentrate on collecting insects in Texas. He sent his specimens, mostly beetles, to his entomologist brother, Samuel S. Haldeman, and a noted beetle expert, John L. LeConte, for description.
- The reference to ironclad in the common name of this beetle results from its very thick exoskeleton—so thick that traditional preservation techniques do not work on this species.
Texas Hackberry Emperor Butterfly
Range: It is found in Texas, western Oklahoma, western Kansas, southwestern Nebraska, New Mexico, Colorado, southern Wyoming, Arizona, Utah (east of the Great Basin), southern Nevada, and southeastern California– as well as in northern Mexico.
Conservation Status: Populations of this species are currently considered secure.
Population threats: The greatest threats to butterflies are habitat change and loss due to residential, commercial and agricultural development. Widespread pesticide and herbicide use has also taken a toll on some butterfly species, including the iconic monarch butterfly.
Diet: Adult female hackberry emperor butterflies feed on the nectar from flowers (especially asters); adult males feed on sap, decomposing fruit, carrion and animal droppings. Caterpillars of the species feed on the leaves of hackberry trees including the desert hackberry and the Texas sugar berry.
Did You Know?
- This species of butterfly lives in varied habitats– but always near hackberry trees (from which it derives its name).
- As adults, members of this species may crave salt, and will even land on people in order to lap up the salt in their sweat.
- Hackberry emperor butterflies often perch in strange places, including sides of houses and (as in our photo) the window to the door of our Zoo Kitchen.
- The eggs of this species are pale green, and are laid either singly or in clusters of up to 20 on the lower surface of leaves of hackberry trees, or sometimes on the twigs or bark.
- The Texas subspecies is the westernmost subspecies of Hackberry Emperor butterfly, a species that ranges as far east as the Atlantic coast and as far north as southern Canada.
Thread-Legged Assassin Bug
Range: Most of the US (from Maine south to Florida in the east, from Wisconsin to Texas in the central states); as far north as Ontario, Canada; and as far south as Brazil.
Conservation Status: None identified for this species.
Population threats: No specific population threats have been noted. The family of insects to which this species belongs is considered beneficial to agriculture. Overuse of pesticides will impact this species both directly and indirectly (through the insects they eat).
Diet: The thread-legged bugs are capable of catching insect prey, but they often take an easier route to finding food– they steal insects caught in spider webs and sometimes eat the spiders themselves.
Did You Know?
- The thread-legged assassin bug is often mistaken for a stick insect. This species is usually about 1 to 1.5 inches in length, but is so thin that it appears to be no more than a slender stick.
- The thread-legged bug is a kind of assassin bug. Other assassin bugs include the kissing bug and wheel bug. On the other hand, walking sticks (which the thread-legged bugs mimic) are closely related to mantises, are herbivorous and do not have predator-like front legs.
- With their front legs having been modified for grasping prey, the thread-legged bugs walk on the rear four legs. When threatened, these bugs may hold their front legs out straight in front of their head, creating the appearance that the bug is a longer, four-legged insect. They can also fly.
- These bugs use their two pairs of remarkably thread-like legs (from which they get their name) to walk among spider webs. From within the web, they pick out insects caught in the silk.
- Thread-legged bugs have also evolved a behavior of plucking the web strands in order to produce vibrations that manipulate the behavior of the resident spider. Once they have the opportunity, a thread-legged bug will snatch the spider with its claw-like front legs, inject it with insecticidal venom, and eat it.
- This species is often found on the outsides of old buildings, and in barns. They may also be found under loose bark.
Giant Redheaded Centipede
Range: This species is found in northern Mexico and the southern United States, from New Mexico and Arizona in the west, to Arkansas and Missouri in the east.
Conservation Status: Although fairly widely distributed, giant redheaded centipedes are not frequently observed or collected. There are specific conservation needs identified for this species.
Population threats: Habitat conversion and imprudent use of pesticides would pose a threat to the species.
Diet: All centipedes are believed to be predators. Their diet is composed primarily of small arthropods, although some have been found feeding on toads, small snakes, and other vertebrates.
Did You Know?
- The largest centipede in North America, the average adult of this species is 6.5 inches long, although individuals as long as 8 inches have been documented.
- All centipede species are venomous, although very few can cause harm to humans. The giant redheaded centipede’s bite is one that can cause significant pain, localized skin damage and symptoms such as vomiting, headaches and dizziness. There are no reliable reports of death resulting from the bite of this species, but its potential for harm should not be underestimated.
- The prey of the giant red-headed centipede is captured and either killed or stunned with the poison claws. Poison glands are located in the basal segments of the claws or fangs (sometimes called maxillipeds).
- The trunk of this species bears 21 or 23 pairs of legs. Unlike millipedes (which are non-venomous and have two pairs of legs per segment), centipedes have one pair of legs per segment.
- The giant red-headed centipede remains underground on warm days, emerging in cloudy weather. They tend to inhabit rotting tree trunks, areas of deep leaf litter and cavities within loosely assembled piles of rocks.
Range: This species is found from southern Canada south to Mexico and in all of the lower 48 states except for Arizona and Nevada.
Conservation Status: Populations of this moth are secure globally, although it may be quite rare in parts of its range.
Population threats: Parasitic insects, such as some species of wasps and flies, lay their eggs in or on the young caterpillars and pose a huge problem. The eggs hatch into larvae which consume the insides of the caterpillars. Once the caterpillars pupate, the larvae themselves pupate, killing the polyphemus pupa. Squirrels have also been known to consume the pupae of polyphemus moths, decreasing the population greatly. Pesticides, pruning of trees and leaving outdoor lights on at night can also be detrimental to the moths.
Diet: Adult moths do not eat and, in fact, have no mouth parts. The polyphemus caterpillars feed on the leaves from a wide variety of trees (including oak, willow, maple, and birch), shrubs (including all members of the rose family), and vines (including grape). They are typically not numerous enough to cause a problem for plants except occasionally in California, where they impact commercial plum crops.
Did You Know?
- Polyphemus moths fall within the family of giant silkworm moths. The larvae (caterpillars) of a few Asiatic silkworm moth species have been used for commercial silk production. The North American ones haven’t proven useful for this purpose.
- Because of the characteristic eyespot on its wings, this moth was named for Polyphemus, the mythological one-eyed cyclops mentioned in The Odyssey of Homer.
- Polyphemus moths are the most widely distributed large silk moths in North America.
Polyphemus antennae are comb-like on four sides. Those of the males are larger than those of females.
- Polyphemus caterpillars gain protection from predators by their cryptic green coloration. When threatened they often rear the front part of the body in a “Sphinx” pose – possibly to make them look less caterpillar-like to a predator.
- If attacked, polyphemus caterpillars (as well as those of many related moths) make a clicking noise with their mandibles – sometimes as a prelude to, or accompanied by, defensive regurgitation of distasteful fluids. Ants and mice were found to be discouraged by the vomit of the polyphemus caterpillars—suggesting that the clicking may serve as a warning to potential predators of the impending regurgitation.
Milkweed Tiger Moth
Range: Maine and southern Canada to Florida; west to Minnesota and Texas.
Conservation Status: Populations are currently considered globally secure, although the species may be quite rare along the edges of its range.
Population threats: Like the iconic monarch butterfly, the milkweed tiger moth depends upon the milkweed plant for its survival. Many of today’s farmers plant herbicide-resistant versions of crops like corn, soybeans, and others. The genetically-modified crops’ resistance to herbicides makes it possible for farmers to spray their fields with powerful chemicals—killing milkweed, and ultimately starving milkweed-dependent butterflies and moths in the process.
Diet: Larvae (caterpillars) of this moth feed on milkweeds and also dogbane.
Did You Know?
- This species is also known as the milkweed tussock moth. As larvae (caterpillars), their Halloween-like coloration has gained them another alternative name— “harlequin caterpillar.”
- The contrasting orange and black colors of its thick hair tufts serve as a warning coloration. The milkweed tiger moth is toxic to any predator that might eat it. Predators learn that eating either adult or larval moths with these colors will make them sick. This chemical defense arises from the toxins found in milkweed, which comprise the diet of the caterpillars.
- These caterpillars are first found in June, having hatched from eggs laid in clusters on the underside of milkweed leaves.
- Although the caterpillars of this species stay together in their earlier lifestages (initial “instars”), they begin to isolate themselves as they get older and ultimately overwinter as hairy cocoons. They generally metamorphose into adult moths by the following May.
- Adult milkweed tiger moths are relatively plain-looking from above. Their wings are usually unmarked gray, but the abdomen is yellow-orange with rows of black spots.
- While the underside of the milkweed tiger moth has bright warning colors to warn daytime flying predators, the moth flies at night and could be attacked by bats that cannot see the warning colors. To overcome this, the moths use a sound organ to make high-frequency clicks that are audible to bats. The warning sounds of these moths advertise their unpalatability to bats and encourage the would-be predators to keep a safe distance.
Blotched Water Snake
Range: This is one of six subspecies of the plain-bellied water snake. The range of our local subspecies includes western Missouri, Kansas, northwestern Arkansas, central Texas, southeastern New Mexico and northern Coahuila, Nuevo Leon and Tamaulipas, Mexico.
Conservation Status: The species is listed as Least Concern in view of its wide distribution, presumed large population, and relatively stable numbers. Some populations are likely threatened due to their extremely limited range and their dependence on tenuous sources of water.
Population threats: Habitat destruction and/or “human contact” have eliminated this species from some parts of its former range, particularly in the north-central part of the species’ range (Great Lakes states). Reduction of the water table (e.g., through irrigation and overuse of aquifer resources) drains the springs and ponds upon which this species depends and threatens some of the isolated populations.
Diet: Like many other water snakes, this species eats aquatic vertebrates such as tadpoles, frogs, aquatic salamanders and fish. In our area, leopard frogs and toads comprise the majority of their diet.
Did You Know?
- Because this snake is found in and around water and– like many water snakes– has a nasty disposition, it is often misidentified as the venomous “cottonmouth” (also known as “water moccasin”). Blotched water snakes are actually harmless.
- Like many non-venomous snakes that feed on large prey, this species has developed a defensive behavior that mimics that of venomous snakes: it will coil up, vibrate its tail, assume a strike posture, and flatten its body near the head to appear larger than it is.
- If you get within reach of a blotched water snake it will strike and bite in self-defense. Though their bite is not venomous, it will draw blood.
- When sitting in water, these snakes only expose their head, with the rest of their body and tail below the surface. This aids them in secretively surveying the surrounding area for approaching prey items.
- Female blotched water snakes give birth to 8 to 30 live young, depending upon the size of the female. Mating occurs in the late spring and females give birth during the late summer. Newborn blotched water snakes are typically between 8 to 10 inches in length and have colorful red-tinged blotches that fade as the snakes mature.
- Ground skinks are one of the smallest reptiles in North America. Including the tail, adults measure only 3-3.5 inches in length.
- Ground skinks overwinter under the leaf litter. When they emerge, they bask atop the leaves and grasses and are more often heard fleeing than they are seen.
- Unlike many other lizards, ground skinks do not climb. Instead of running on their tiny legs, ground skinks use their slender bodies to wriggle or “swim” through leaf litter or loose soil, often quickly disappearing from view the moment they become exposed.
- When grasped by would-be captors, ground skinks may drop (“autotomize”) their tails. After falling off, the tail thrashes conspicuously, distracting the predator long enough to allow the skink to escape. The tail will eventually grow back, although at significant expense to the lizard.
- This species is oviparous (lays eggs). Mating occurs from January to August. A clutch of 1 to 7 eggs may be laid almost monthly from April to August, with a maximum of 5 clutches per season. Ground skinks do not provide parental care to their offspring: the female abandons the nest immediately after egg-laying.
- A harmless species, this snake helps to control the populations of invertebrates and small, cold-blooded vertebrate prey.
- In Texas, this species is active from as early as March until October. Its activity levels peak by day in cool weather, at dawn and dusk in spring and fall, and at night in summer.
- Although it is not restricted to areas with permanent water, the checkered garter snake seems to be most abundant in the vicinity of ponds, moist grasslands, tanks, drainages, irrigated areas, and rivers.
- Garter snakes are live-bearing snakes. The female will give birth to a single litter each year. Litter size can range from 5 to 35; in Texas, the average is about 13.
- When captured, garter snakes often expel a foul-smelling material called “musk” to encourage would-be predators to release them.
- The common name of this tarantula attributes the species to three states: the Texas brown tarantula, the Oklahoma brown tarantula and the Missouri tarantula are all the same species.
- Texas brown tarantulas can grow to have a leg span in excess of six inches, and weigh more than 3 ounces as adults.
- Like most other tarantulas, the Texas brown will stand on its hind legs and raise its front legs when disturbed. In spite of this threat display, it is a docile species. Texas brown tarantulas also have small needle-like, barbed hairs on their abdomen (called urticating hairs) that they will kick in the direction of whatever makes them feel threatened. Bites from the Texas brown tarantula are not only rare, but generally cause no more serious harm to humans than a bee sting.
- Texas brown tarantulas may be active from June through October but are most commonly seen in June and September. Males wander in search of females and are therefore more likely to be seen during the day.
- Females have lived in captivity for over 25 years. Males in Texas rarely live over two or three months after maturity.
- This large toad species can grow to a length of 5 inches. Individuals have been known to live 8 years in the wild.
- Males Gulf coast toads have throats that are yellow-green. The females’ throats are not pigmented.
- Eight species of true toads are known to inhabit Travis County. This species is, by far, the most abundant one at Austin Zoo.
- Unusual among toads, Gulf coast toads could be considered arboreal. Field researchers found this species from 6 to 16 feet above the ground in oak trees. Individual toads will find tree holes and may use them repeatedly for periods of weeks.
- Like other true toads, secretions from a Gulf coast toad’s parotoid gland (the large oblong lumps behind their eyes) are apparently distasteful to some predators. The eggs of the Gulf coast toad are also toxic and/or distasteful to a wide variety of would-be predators.
- While this is the most common praying mantis species in North America, it is only one of several species to be found in Texas.
- Female Carolina mantises deposit eggs on plant stems. The eggs are surrounded by a hard, oval, protective case called an ootheca. It is formed from a liquid substance secreted by the female which, upon exposure to the air, quickly hardens.
- Within a few weeks after mating, a female praying mantis usually dies. The male can literally lose his head during the mating process– the female may simply bite it off and eat it.
- The Carolina mantis uses a “sit-and-wait” tactic of obtaining its food. It will often wait quietly near a flower and attack the insects that approach the flower to feed. Once within reach, the mantis attacks, grabbing its prey with its forelegs.
- The Carolina mantis is the state insect of South Carolina.
- When well warmed up these lizards can attain surprising speed– up to 18 miles an hour.
- This species is most common in hot, open areas such as fields, woodland edges, and sand dunes and is almost always found on the ground.
- The tail of the six-lined racerunner is nearly twice the length of the lizard’s body.
- These predatory lizards are valuable allies in the control of insects in various parts of the country. They are important as consumers of agricultural pests such as the beet leafhopper in Utah. In Florida they are significant in the control of insects that would damage celery crops.
- Female racerunners produce four to six eggs from early June to middle July. They are laid four to twelve inches below the surface, frequently under some object on the surface such as a log.
- Despite its bright colors this spider is not a danger to humans. It is very unlikely to bite unless severely provoked, and in that case the bite would be probably no worse than a bee sting.
- Yellow garden orbweavers are the largest web-making spiders in our area. The body of a large female (legs not included), can be as long as one whole inch.
- Like many spiders, female yellow garden orbweavers are larger than males. In this species they are three to five times larger.
- The yellow garden orbweaver spins a very complicated web shaped like a circle (“orb”) which is sometimes greater than two feet in diameter. The female builds the large web, and a male will build a smaller web on the outer part of her web. The male’s web is a thick zig-zag of white silk.
- This spider will rapidly shake and vibrate in its web as a defensive strategy to scare predators off. The shaking blurs the spider and makes it appear bigger than it really is. The web of this species is usually eaten and rebuilt every day except during the periods where the spiders are molting and egg-laying.
- When approached, the greater aridlands katydid may rear up in a formidable display. If handled carelessly, it may bite and even draw blood.
- The original studies of this species referred to it as the ‘Red-eyed Devil,’ in part due to the color of its eyes.
- The bodies of large female greater aridlands katydids can be two inches long.
- Whereas cicadas typically call during the day, the insects that call at night are crickets and katydids. Crickets have a high-pitched chirping call, katydids often sound as if they say “Katy did; she didn’t; she did; she didn’t,” especially if there two individuals calling to one another. This species continuously repeats a loud resonant phrase about once per second, only at night when temperatures exceed 77 degrees.
- The most common rabbit species in Texas, identifiable by its distinctive white tail. This white tail is the source of their common name.
- Eastern cottontails have two different fur coats each year. During the summer they have short brown fur with a white belly. During the winter the fur becomes longer and grayer, also with a white belly. All year long the underside of the tail is white.
- Cottontails are typically challenging to see up close due to their shy nature and great speed. Several that call Austin Zoo home are much calmer and will tolerate guests approaching them.
- In Texas, eastern cottontails breed throughout the year. As many as four or five litters of one to eight young (average, four) may be reared yearly after a pregnancy (gestation period) of 28-29 days.
- Because of their role in the food chain, some people consider this species to be the most important regulated game animal in the U.S.
- Perhaps the most commonly seen lizard on zoo grounds.
- Most often seen on the ground, these lizards will run up trees and posts in order to escape danger.
- Male spiny lizards have a blue patch on each side of their belly and light stripes running along the upper edge of their backs; adult females have wavy dark lines on their backs which sometimes extend to their upper legs.
- Male Texas spiny lizards have a peculiar habit when challenged by another male for their territories. The two males will appear to have a push up contest. Both males will begin doing push-ups until one of them gives up and runs away. The winner gets the right to stay.
- A female Texas spiny lizard might lay up to four clutches of eggs over the spring / summer breeding season.
Range: This species’ natural range lies entirely within the United States. It can be found from New Jersey to southern Florida on the East Coast, as far west as Kansas and Texas, north to the southern Midwest states, and south to the Gulf Coast.
Conservation Status: The conservation status of the ground skink is categorized as Least Concern in light of its large range, occupancy of relatively stable habitat, and sizeable population.
Population threats: No major threats are known. Skinks are vulnerable to secondary poisoning: inappropriate use of pesticides can introduce contaminated food to these beneficial (and harmless) reptiles. In addition, feral cats are significant predators of this species.
Diet: Eats mainly insects; also spiders, worms, and other arthropods.
Did You Know?
Range: The range of this species extends from southeastern California, southern Arizona, New Mexico, and southern Kansas southward through Oklahoma and Texas to northern and central Mexico. Scattered populations exist in southern Mexico, Belize, Guatemala, Honduras, and from Nicaragua to Costa Rica. It inhabits areas with elevations from near sea level to over 7,000 feet.
Conservation Status: The checkered garter snakes’ numbers appear to have increased in some areas and declined in others. Currently its overall population trend is of relatively low conservation concern and the species is said not to require significant additional protection or major management, monitoring, or research action.
Population threats: There are no major known threats for this species in North America. Some small and fragmented subpopulations in southern Mexico and Central America are being affected by habitat conversion for agricultural purposes, the use of pesticides, and declining amphibian populations that are used as prey.
Diet: The checkered garter snake eats fishes, frogs, toads, tadpoles, lizards, and invertebrates.
Did You Know?
Texas Brown Tarantula
Range: Louisiana north to Kansas and west to Arizona and Texas.
Conservation Status: Not assessed. This species is one of the most common species of tarantula and is thriving in the southern-most United States today.
Population threats: While this species is not yet imminently threated, land development and habitat alteration have a negative effect on all tarantulas—some of which are critically endangered.
Diet: Tarantulas will feed on any live animal they can catch and overpower, including large insects such as crickets, grasshoppers, and beetles.
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The Gulf Coast Toad
Range: Southern Arkansas, southern Mississippi, Louisiana, and central Texas in the USA, southward to Palma Sola, Veracruz, Mexico.
Conservation Status: It is a widespread and common species in suitable habitat. Its ability to adapt to human-altered environments would seemingly give it an advantage in terms of expanding its range.
Population threats: Not threatened.
Diet: The Gulf coast toad is an opportunistic feeder which preys primarily on insects and is most active at twilight. Isopods (“pill bugs”) are a favorite. It will also hunt near the artificial light sources to which their food is attracted.
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The Carolina Mantis
Range: This species is found in southern North America, from the state of New Jersey west to Illinois, Missouri, Texas, and Arizona, and down through Mexico to Central America.
Conservation Status: Not listed as threatened at this time.
Population threats: The introduction of a praying mantis from China (to combat insect pests) has led to declines in population numbers of the native mantis species in some areas. The Chinese mantis is thought to outcompete many of the native mantids, as well as to actually consume the local mantis species.
Diet: As generalist predators, praying mantises mostly consume pests such as flies, crickets, moths and mosquitoes. They also devour other beneficial insects, including each other. The Carolina mantis is known to even attack small frogs and lizards.
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Range: In the eastern US, this species exists from Maryland in the north to southern Florida. In the central US it ranges from Wisconsin, west to eastern Wyoming, eastern Colorado, eastern New Mexico, and central Texas, and then as far south as southern Texas and then follows the Gulf Coast—as far as extreme northeast Tamaulipas, Mexico.
Conservation Status: The IUCN has designated the conservation status of six-lined racerunners as “Least Concern,” meaning the population is either stable or very slowly declining.
Population threats: No major threats have been identified for this species. Locally, some populations have declined or disappeared as a result of conversion of habitat to human uses. Historically, much of their habitat may have been lost through agricultural expansion.
Diet: Racerunners are voracious feeders. Their diet consists primarily of soft-bodied insects but also includes other arthropods and snails. Grasshoppers, crickets, spiders, ants, flies, small moths, and moth or butterfly larvae are preferred prey.
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Yellow Garden Orbweaver
Range: These spiders occur from southern Canada south through the lower 48 United States, Mexico, and Central America as far south as Costa Rica. It is uncommon in parts of the Rocky Mountains and the Great Basin.
Conservation Status: Widespread and numerous throughout their range.
Population threats: While there are no threats specifically noted for this species, all insects are vulnerable to localized loss as a result of the indiscriminant use of pesticides.
Diet: An insect predator, orbweavers eat a wide range of flying prey including flies, moths, beetles, wasps, mosquitoes, etc. They are considered a beneficial insect.
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Greater Aridlands Katydid
Range: Native to much of Texas, the species ranges from the Red River to the Rio Grande, and as far west as southeastern Arizona.
Conservation Status: Undetermined.
Population threats: While there are no specific threats to its population, this spectacular insect can be the victim of indiscriminate pesticide use. Also, the oak-juniper, mesquite, bushland, shrubby desert habitats upon which it depends are often under pressure to be converted for other uses.
Diet: Although omnivorous, the greater aridlands katydid can be a voracious predator. It feeds on grasshoppers, other katydids, caterpillars, small frogs, lizards and geckos. They have even been known to eat nestling songbirds.
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Did You Know?
Texas Spiny Lizard
Range: This species’ range includes Texas and adjacent northeastern Mexico. It is found from south of the Red River (Oklahoma/Texas border) into northern and eastern Mexico, as far south as southern Tamaulipas, central Nuevo Leon, and San Luis Potosi.
Conservation Status: The Texas spiny lizard is not considered threatened. The total adult population size is unknown but surely exceeds 100,000. It has been found in virtually every county in Texas and is common to abundant wherever the species is found. The populations are fine in Mexico.
Population threats: Because the area occupied by the species and its population size are large, no threats to the species’ survival have been identified.
Diet: Primarily eats insects, although some small vertebrates may also be consumed.
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