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| Marine Blue (Leptotes marina) |
The gossamer-winged butterflies (or Lycaenidae) are a large family of small butterflies that include the coppers, hairstreaks, and blues. Usually noticed when flying erratically in an up-and-down fluttering motion, they bask in the sun with their wings open, and when perched sit with their wings closed, often rubbing their hind wings together. The blues are especially small with a wingspan of about one inch, and while mostly blue above, the identifying field marks are found mainly on the undersides of their wings. In Central Texas, the most commonly seen blues in open, sunny habitats are the Eastern Tailed-blue, Marine Blue, and Reakirt’s Blue.
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| Eastern Tailed-blues (Cupido comyntas) |
Eastern Tailed-blues (Cupido comyntas) are common and can be identified by the one to three orange spots near the tail on the underside of the hind wing. The males are deep blue on their uppersides while the females are a lighter blue to brown. They occur in the eastern half of the United States from the coast to the Great Plains.
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| Marine Blue (Leptotes marina) |
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| Marine Blue (Leptotes marina) |
The Marine Blue (Leptotes marina) is a fast flier (for a blue) and is found from Texas west to Southern California and south to Mexico. Its’ underside is strongly striped gray-brown often with a pale purple fringe. The male has a blue upperside with a strong purple overlay, while the female has a brown upperside with some blue at the base of the wings.
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| Reakirt's Blue (Echinargus isola) |
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| Reakirt's Blue (Echinargus isola) - male |
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| Reakirt's Blue (Echinargus isola) - female |
While the other blues fly mostly spring to fall, Reakirt’s Blue (Echinargus isola) flies year round in Texas. The males are lavender-blue above while the females are primarily gray-brown with a touch of blue basally, and they are identified by the conspicuous row of five white-ringed black spots on the underside of their forewings.
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| Western Pygmy-Blue (Brephidium exilis) |
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| Ceraunus Blue (Hemiargus ceraunus) |
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| Cassius Blue (Leptotes cassius) |
Other species that are not common in our area but can sometimes be found include Western Pygmy Blue (Brephidium exilis), Ceraunus Blue (Hemiargus ceraunus), and Cassius Blue (Leptotes cassius). With a wingspan of about half an inch with coppery brown on the underside, the Western Pygmy Blue is the smallest butterfly in North America. Ceraunus Blue and Cassius Blue both have a wingspan of about one inch, and have two submarginal eyespots on the underside of the hindwing (in Florida, the Ceraunus has only one eyespot). They can be distinguished from each other by the patterns on their undersides, with the Ceraunus having a row of dark postmedian dashes on a gray background, and the Cassius having broken pale lines with some white or 'blank' spots on a tan background.
Most of these blues utilize legumes as their larval food plants, so you can often see them flying around plants in this family, including alfalfa, mesquite, clover, dalea, mimosa, and indigo species. The caterpillars of these butterflies are slug-shaped, somewhat flattened, and are often tended to by ants, which feed on the sweet liquids secreted by the larvae and in turn protect the larvae from other predators. As adult butterflies, they feed on nectar from a variety of herbs found flowering in grasslands, fields, meadows, and along creeksides.
Interestingly, these blues are part of a group of butterflies called the Polyommatus blues, originally studied by the self-taught butterfly expert and famous mid-twentieth century novelist Vladimir Nabokov, who hypothesized that they arrived in the New World from Asia in waves over millions of years. While few professional scientists took his ideas seriously at the time, recent DNA and gene-sequencing technology has proved him absolutely correct – that this group of butterflies originated in Asia, moved over the Bering Strait at a time when the land was relatively warm 10 million years ago, and eventually headed south all the way to Chile!
