Outmaneuvering Mosquitos

Mosquitos can be a nuisance in the hot summer months.

As the temperatures start to increase so do the ads for mosquito-control companies that offer to blanket spray residential landscapes.  While many of these businesses claim that their treatments only kill mosquitos and other pests, in reality the broad-spectrum insecticides they use kill many other species.

Broad-spectrum insecticides are indiscriminate, and along with killing mosquitos, they also kill pollinators and other beneficial insects such as bees, butterflies, moths, caterpillars, dragonflies, damselflies, and lady beetles.  The damage continues further up the food chain, when birds die as their insect food disappears and aquatic animals such as fish die when these chemicals wash off our landscapes and flow into nearby creeks, ponds, rivers, and lakes. Even spraying with essential oils such as peppermint, rosemary, and lemongrass is discouraged, as these can also kill beneficial insects.

Keeping mosquitos at bay can be vital, with many mosquito-borne tropical diseases such as West Nile, Zika, and Dengue fever spreading in range.  However, there are other natural, safer alternatives to using broad-spectrum insecticides.  It starts with understanding that mosquitoes can breed in less than one inch of water, and that the most effective way to reduce their numbers is to target the larvae, not spray adults.  

Moving water discourages female mosquitoes from laying eggs.

Begin by removing any standing water in gutters, bird baths, flower pot saucers, children’s pools, pet bowls, watering cans, and anything else that can hold water. Female mosquitoes avoid laying eggs in moving water, so consider adding a small pump or fountain to a water feature. For standing water that cannot be drained, use a mosquito dunk that contains the natural bacterium Bti (Bacillus thuringiensis israelensis) that kills mosquito larvae as they hatch, and consider adding native mosquitofish (Gambusia species) if the water feature is permanent.  Mosquitos are weak flyers, so even setting up fans reduces their ability to find an individual.

Black-chinned Hummingbirds get protein from eating insects like mosquitoes.

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Neon Skimmer dragonflies love to prey on mosquitoes.

Most surprising to many, those who garden for wildlife using native plants have fewer mosquito problems than those with non-native turf lawns.  Native plants attract natural mosquito predators such as birds (warblers, wrens, woodpeckers, hummingbirds), dragonflies, damselflies, frogs, turtles, and bats.  Hummingbirds consume hundreds of insects daily in addition to drinking nectar, dragonflies and turtles eat mosquito larvae before they can hatch, frogs specialized sticky tongues nab all kinds of insects, and bats consume millions of insects on the wing.

The sticky tongues of frogs like this Leopard Frog can catch adult mosquitoes.

Red-eared Slider turtles eat mosquito larvae before they hatch.

It is important to note that even if you have a native landscape and don’t spray for mosquitos but your neighbors do, you will still lose pollinators and other beneficial insects.  Recent studies have shown that nearly 3 billion birds have disappeared from North America since 1970 due to loss of their insect prey, and many insect species are rapidly declining or vanishing altogether. 

Make your voice heard by spreading the message that insecticides are significant contributor to wildlife decline, and how we outmaneuver mosquitos in our landscapes truly matters to us all.

Beautiful Hindwings

Can you find the underwing moth?

Commonly known as underwings, the genus Catocala is a large group of moths where most species are somberly clad with brown or gray-shaded forewings, often in variable, cryptic patterns of wavy lines closely resembling tree bark.  It is their hindwings, kept hidden at rest, that are typically a vivid orange, red, or yellow, and marked with black bands or stripes. 

The genus Catocala comes from the Greek kato meaning ‘rear or lower one’ and kalos meaning ‘beautiful’, together translating to ‘beautiful hindwings.’ Of the more than 100 underwing species found in the United States, 15 or so are known in Travis County, including the Ilia Underwing (Catocala ilia), Little Nymph Underwing (Catocala micronympha), and Ultronia Underwing (Catocala ultronia).

Ilia Underwing

The Ilia Underwing, also known as the Beloved Underwing or Wife Underwing, is one of our most common large underwings.  It has a total length to 1.8 inches, and gray to brownish forewings with a bold black line above a white or white-outlined spot. The reddish-orange hindwings have two black bands, and a pale orange, checkered fringe.  It utilizes oaks for its host plants, especially red oaks such as Shumard’s Oak and Southern Red Oak.  Its common and scientific name Ilia likely refers to the mythical mother of the twins Romulus and Remus, who were the mythological founders of the city of Rome.

Little Nymph Underwing

One of our smaller underwings with a total length of up to 1 inch, the Little Nymph Underwing has brown to grayish forewings typically marked with a dark, curving, shadow-like crescent.  The golden orange hindwings have two black bands, sometimes broken, and a pale, checked fringe.  It prefers white oaks as host plants, specifically Post Oak, Bur Oak, and Coastal Live Oak.  Its species name comes from the Greek and means ‘little bride or mistress.’

Ultronia Underwing

The Ultronia Underwing is medium-sized underwing to 1.3 inches in length, and is identified by its grayish-brown forewings marked with a darker brown shading on the inner edge.  The reddish hindwings have two black bands and a mostly gray fringe. Escarpment Black Cherry and Coastal Live Oak are its preferred host plants, and its common and scientific names are said to have come from the name of a Greek island.

It is believed that the bright colors of these moths’ hindwings, which usually form roughly concentric patterns, resemble the eyes of a predatory animal when suddenly flashed toward danger. Underwings are also said to possess fairly well-developed hearing organs, allowing them to evade nocturnal predators such as bats.  Their cryptic forewings keep them hidden during the day as they roost on tree bark and in crevices, and even in their larval form their coloring and patterns often mimic gray bark or green lichen.  While most active shortly after nightfall, several species have a second activity period for a few hours around noon, when these beautiful hindwings can sometimes be found on the wing in broad daylight!

Bodacious Borers

Cottonwood Borer

As spring turns into summer in Central Texas, the heat brings out some of our most interesting creatures, most notably the native wood-boring beetles.  This group encompasses many species and families of beetles, all of whom eat wood either in their larval or adult form.  Most often they are found in or around dead or dying trees, as they are vital players in enabling the turnover of weak trees with strong ones, and acting as primary decomposers of wood which allows for the recycling of nutrients back into the soil.

One large family of beetles in the wood-boring group is the longhorn beetles, or Cerambycidae, typically characterized by their extremely long antennae which are often as long or longer than the beetle’s body.  Their family scientific name comes from the mythological Greek shepherd Cerambus, who was turned into a large beetle with horns after an argument with nymphs.  Three of the more noticeable wood-boring longhorn beetles in our area include the Banded Hickory Borer (Knulliana cincta), Cottonwood Borer (Plectrodera scalator), and Texas Bumelia Borer (Plinthocoelium suaveolens plicatum).

Banded Hickory Borer

With a body length of up to 1.4 inches, the Banded Hickory Borer is a fairly slender, typically gray to reddish-brown beetle with a pair of pale marks near the base of the elytra or wing covers that are sometimes absent, and tiny spines at the ends of the elytra.  Eggs are laid by the adults in bark crevices or directly into hardwoods such as oak, pecan, walnut, willow, and hackberry, upon which their larva feed.  In their first season, the larva feed just beneath the bark, then head deeper into the wood as they develop, a cycle which takes two to three years to complete.

Cottonwood Borer

The Cottonwood Borer is an elongate, unmistakably robust beetle with black and white markings that are formed by contrasting areas of white pubescence or fine short hairs on black body parts.  At a body length of up to 1.6 inches, the summer-active adults lay eggs in August and September on cottonwood and willow, where larva bore into the base and overwinter.  After two or three years to reach maturity, they pupate in chambers beneath the bark and emerge as adults in late spring, and are often found feeding on new shoots, leaf petioles (stems), and the bark of their host trees.

Texas Bumelia Borer

One can hardly miss the bright iridescence of the metallic green Texas Bumelia Borer, with its contrasting reddish-orange and black legs. The larva of this species feed on gum bumelia and mulberry, developing in the roots and trunks of these host plants.  With a body length of 1.5 inches, the adults are diurnal and often found on the trunks of their host plants, although they typically feed on flower nectar and are attracted to lights.

Despite their large size, most native wood-boring beetles are not pests.  Instead, they take advantage of dead and dying trees and aid in the natural decomposition process. As you venture out and about this summer, see if you can find some of these bodacious borers!

Beguiling Bloomers

Pink Stonecrop

Springtime in Central Texas brings a host of familiar wildflowers blooming in meadows and woodlands, and along grassy roadsides. But each year the seasonal conditions may vary, based largely on the timing and amount of rainfall.  While many species are widespread from year to year, some appear infrequently, others only in certain habitats, and many go almost completely unnoticed.

Clasping Venus’ Looking-glass

Clasping Venus’ Looking-glass or Clasping Bellflower (Triodanis perfoliata) is a distinctive annual that can be found growing in open often disturbed areas, sometimes appearing even in cultivated flower gardens.  In April and May, violet-blue, 5 petaled, wheel- to bell-shaped flowers, 0.5 to 0.75 inches across, are set singly in the axils of rounded green leaves that clasp the erect, slender, unbranched stems.  Inconspicuous at 6 to 18 inches high, this species is differentiated from five other Triodanis species found in Texas by its almost circular, toothed, clasping leaves.

Pink Stonecrop, also called Widow's Cross

Pink Stonecrop or Limestone Stonecrop (Sedum pulchellum), is a low-growing, apparently rare annual found on rocky ground in full sun, often among cactus and other Sedum species. Smooth, stem-clasping, cylindrical pale to lime green leaves (often with a reddish tinge), to 1 inch long, are densely arranged along the ascending to spreading stems.  These stems are topped with horizontally branched inflorescences that bloom from March to May, with numerous 4-petaled, pale pink flowers, to 0.5 inches across.  The petals are arranged in a cross-like pattern, giving rise to its other common name of Widow’s Cross. The Travis County population of this species, most often found on hilltops in the Bull Creek watershed, is disjunct by over 150 miles from other more eastern and northern populations, and likely represents the southwestern limit of its native distribution.

Heller's Plantain

Highly overlooked but quite common is Heller’s Plantain or Cedar Plantain (Plantago helleri), an erect annual that grows only in Central to West Texas and in southern New Mexico, typically in shallow, stony soils and on limestone bedrock exposures. From March through May, this species displays unusual, slightly overlapping flowers clustered at the top part of each stalk.  The flowers are quite small at 0.25-inches wide, with 4 off-white, nearly translucent petals that have a dark red center.  The stalks, to 10-inches high, arise from narrow, linear, basal leaves, to 8-inches long, and both stalks and leaves are softly hairy.  This species is can be commonly found along gravelly roadsides, and it is one of the host plants for the beautiful Common Buckeye butterfly.

Common Buckeye

Each spring, remember to look beyond the bluebonnets, paintbrushes, firewheels, and Mexican hats and take a closer look, because you just might be rewarded with one of these beguiling little bloomers!

Resilient Trees

The beginnings of Winter Storm Uri

With winter storm Uri well behind us, many observations are being made regarding which tree species successfully survived the 8-day stretch of extreme winter weather conditions.  First and foremost, all trees that are native to Central Texas generally fared much better than their non-native counterparts.  Over the centuries, native species have adapted to all sorts of weather conditions, from cycles of droughts and floods, heat and cold, and even accumulations of ice or snow.  These adaptations greatly increase each native species’ resiliency over time.

A second factor that determined the survival of a native tree species was whether it was evergreen or deciduous.  The foliage of evergreen species increases the surface area that can trap ice and heavy snow, causing limbs to bow, split, and break, which can weaken the entire structure of the tree.  While deciduous trees can be covered in ice and snow, in winter they do not have foliage that can trap the extra weight that can cause permanent damage.

Third, established plants have a much better chance of survival in extreme winter weather conditions, so now is the time to plant!   While there are many desirable native trees that are deciduous, there are several that are also attractive bloomers in the spring, including Escarpment Black Cherry (Prunus serotina var. eximia), Roughleaf Dogwood (Cornus drummondii), and Rusty Blackhaw Viburnum (Viburnum rufidulum).

Escarpment Black Cherry in bloom

Escarpment Black Cherry fruit

Found only in the limestone-based soils in Central Texas, Escarpment Black Cherry is a distinct and isolated subspecies of native Black Cherry (Prunus serotina). Growing up to 50 feet tall, it is distinguished from other subspecies in Texas by its intermediate height and its virtually hairless, pointed elliptical green leaves with finely toothed margins that turn golden yellow in fall. It has attractive silvery bark and long showy clusters of tiny white flowers in March to April followed by purplish-red fruits that are favored by wildlife.  This native cherry prefers sunny areas in wooded canyons and on slopes, and is a larval host plant for many species of butterflies and moths including Eastern Tiger Swallowtail, Two-tailed Swallowtail, Cecropia Moth, and White Furcula.

Roughleaf Dogwood in bloom

Roughleaf Dogwood fruit

Roughleaf Dogwood is a small tree to 16 feet with opposite, prominently veined, oval, green leaves with an abruptly drawn-out tip, slightly rough above and slightly velvety below, that turn purplish-red in fall.  From April to early June numerous broad clusters of cream-colored flowers appear at the ends of branches, developing into small, fleshy, bright white, spherical fruits.  This native dogwood prefers partially shady, wooded limestone hills, and provides cover for various species of wildlife, especially birds, as it spreads from root sprouts and if allowed, eventually creates a natural thicket.

Rusty Blackhaw Viburnum in bloom

A shapely small tree, typically to 18 feet but sometimes taller, Rusty Blackhaw Viburnum has attractive, glossy dark-green paired leaves that turn reddish-purple in fall, reddish-brown twigs, and dark bark that separates into rectangular plates. Platter-shaped clusters of tiny, creamy white flowers in March to April are followed by small, oval, waxy, blue-black fruits that are relished by several species of birds and mammals.  This native viburnum prefers woodland edges and thickets in partial shade, and is of special value to native pollinators like bumble bees.

Rusty Blackhaw Viburnum fruit

Rusty Blackhaw Viburnum fall color

It’s important to note that while winter storm Uri was no doubt an exceptional weather event, it’s never too early to plant some of our more resilient native trees!

Ancient Alligators

Texas Alligator Lizard

An ancient and widespread lizard family, Anguidae originated in the Triassic Period, over 100 million years ago.  Today there are 67 species recognized worldwide, with 8 found in North and Central America. Members of a large branch of the snake/lizard evolutionary tree that use their strong jaws rather than tongues to draw food into the mouth, Anguids reserve their hard, slightly forked tongues as chemosensory organs used to search for food, mates, and safe refuge.  

One subfamily within this group is called the alligator lizards, so named due to a vague resemblance to an alligator – a flat, wedge-shaped head, little neck definition, small, thin legs, and scales fairly large and shingled that barely overlap one another. These lizards shed in one piece, much like a snake, turning the old skin inside out as they crawl out of it.  They can also exhibit tail autonomy, the ability to shed their tail as a self-defense mechanism to elude a predator’s grasp and allow escape. While they have the ability to regrow their tail over a period of weeks or months, the new tail is often shorter and distinctly different in appearance from the original tail.

The only species of alligator lizard in Texas is the Texas Alligator Lizard (Gerrhonotus infernalis). Males have wider, more triangular heads than females, but both can grow up to 18 inches long, including their tail. Ground color ranges from light tan to dark brown, sometimes with a reddish cast, with 7 to 10 black and white flecked bands across the body. Newly hatched individuals look entirely different than the adults, with striking copper-colored heads and boldly banded black and cream bodies that resemble centipedes or millipedes.

Generally preferring moist areas of foothills to lowland limestone canyons, staying near springs, creeks, and streams, the Texas Alligator Lizard can even be found in suburban areas near these habitats.  They feed primarily on insects, spiders, and small vertebrates. However, they are secretive in nature, hiding under surface cover such as fallen tree limbs, forest undergrowth, and in rocky crevices.  They can be pugnacious when caught, often thrashing about and able to deliver a painful bite. When threatened by a predator, they may flee to water as they are good swimmers, or perform lateral undulation by folding in their thin limbs and slithering away quickly like a snake.   

Depending on the temperature or season, Texas Alligator Lizards may be active by day or night. In spring they are often arboreal as their tails are prehensile and assist in climbing, mating and feeding in vine tangles and other dense vegetation up to 9 feet off the ground.  Fall is mating season, with males fighting each other for the right to court a female.  Eggs are laid in clutches of 5 to 31 under rocks and in crevices between February and June, with females producing a second clutch if conditions are favorable. Unlike many other reptile species, females will remain with their clutch of eggs for the few months it takes them to incubate.

Texas Alligator Lizards are found throughout a few disjunct localities in the Big Bend region and in much of the Edwards Plateau, and are the largest limbed lizards in Texas. While their secretive nature means they often go undetected, it is a special treat to discover and observe one of these ancient alligators!

A Water Dance of Grebes

Eared Grebe in winter plumage, lacking the characteristic and showy golden ‘ear’ feathers.

Winter is one of the best times to observe waterfowl in central Texas. Several species spend the colder months on our quiet lakes, reservoirs, and ponds, searching for food in the open, unfrozen waters.  One interesting family that can be seen this time of year are the grebes, aquatic diving birds known for their strong swimming, but not often seen on land or in flight.

Grebes are not ducks, although both are considered to be waterfowl.  They lack webbed feet like ducks, and instead have lobed toes.  Their legs attach further back on their bodies than ducks, making it supremely awkward for them to walk on land. Combined with their lobed toes, however, these attributes make them powerful swimmers and divers for their size.  In our area, there are three species of grebe that can be observed, the Pied-billed Grebe (Podilymbus podiceps), the Least Grebe (Tachybaptus dominicus), and the Eared Grebe (Podiceps nigricollis).

Pied-billed Grebe

The Pied-billed Grebe is a small but chunky waterbird 13.5 inches long that is brownish overall with a blocky head, short thick bill, and almost no tail.  During breeding season, its pale bill has a vertical black stripe, which gives it its name as ‘pied’ means having two or more different colors.  These grebes can trap water in their feathers, giving them control over their buoyancy, sinking deeply or exposing as much or as little of their body as they wish. The Pied-billed Grebe is present year-round, but are more abundant from mid-September to mid-May.  They are not gregarious, so they are often solitary or found in very small groups.

Least Grebe

Least Grebes arrive in central Texas in mid-September, but become scarce by early February.  As the smallest grebe in North America at 9.75 inches long, they have golden yellow eyes, a slim dark bill, are purplish gray in summer, and overall gray brown with a whitish throat and paler bill in winter.  Rather uncommon or local, they can sometimes hide by submerging their entire body under water with only their bill visible.  The Least Grebe is light and has large wings relative to its size, so it can take flight from the water more easily than most other grebe species.

Unlike the previous two grebes, the Eared Grebe is the most abundant grebe species in the world, but it is largely a winter resident in Texas, typically appearing by October and disappearing by May.  It is also a small waterbird at 12.5 inches in length with a bright red eye, very thin bill, and overall dusky brown with white.  In their summer range further north and west, they are black with chestnut sides, and sport golden ‘ears’ or wispy feathers that fan out noticeably from their cheeks behind their eyes. Eared Grebes migrate only at night, and their southward migration in the fall is the latest of any bird species in North America.

The collective noun for a group of grebes is a ‘water dance’, which refers to the fact that they have some of the most elaborate courtship displays of all birds.  Often described as ballet-like, these displays can include bowing, feather fluffing, and rising up nearly out of the water, extending their necks and appearing to run across the water’s surface.  Displays vary and can occur between mated pairs or two competing males, suggesting that they have multiple functions.

Get out this winter and scan the open waters for these beautiful little birds.  While they are not particularly common, nor do we normally see them in the height of their breeding plumage, they are still standouts among the typical rafts of ducks that overwinter in our area.