Butterflies with “snouts”?
American Snout butterflies (Libytheana carinenta) do seem to have a nose-like projection at the front of the head. This distinctive, un-butterfly-like feature is formed from extensions of some of the mouthparts.
Like other butterflies, American Snouts “smell” using their antennae.
And the snout-like projection may actually function in camouflage. When perched on a twig, an American Snout often hangs downward with folded wings, whose drab undersides look like a dead leaf. Held closely together, the “snout” and the antennae resemble the leaf stalk.
By contrast, the upper surfaces of the wings are more colorful – brown with white and orange markings – and they’re visible when the butterfly opens and closes its wings while basking in the sun.
As butterflies go, the American Snout is fairly small, with a wingspan of two inches or less. It’s easy to identify by the “snout,” along with its distinctly shaped forewings, which are squared-off at the tips. The species occurs throughout most of the eastern U.S., parts of the Midwest, and southward into northern Mexico. Other types of snout butterflies are found in the Caribbean.
American Snout caterpillars are green with a profusion of tiny yellow dots, plus thin yellow stripes along the sides and back. They eat the leaves of hackberry and sugarberry, native shade trees often used in landscaping.
In the Southeast, the American Snout is resident year-round, with several generations per year. It’s not considered an abundant butterfly in our area, but huge mass movements have been recorded in other parts of the country. For example, in south Texas, a few weeks after heavy rainstorms in September, 1921, some 6 billion butterflies (according to rough estimates) flew en masse in a southeasterly direction over a period of eighteen days.
Since then, similar spectacles have been recorded in Texas and other parts of the species’ range. At times, according to observers, thousands of American Snouts darkened the skies, streamed through backyards, perched freely on plants and people, and even slowed passing traffic. Other local outbreaks have been smaller, but still impressive.
A key trigger for such mass movements may be rainfall fluctuations and their effect on food availability and parasites. But many questions remain, and snout butterflies continue to be a source of local fascination and scientific study.