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Wednesday, July 28, 2021

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.





Saturday, July 24, 2021

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!