Big Country Audubon Society

Big Country Blog

What Are All These Butterflies…

…all over the place?

snout butterfly

They are known as snout butterflies (photo: Bruce Marlin) because they have a prominent elongated mouthpart (labial palpi) which give the appearance of the petiole (stem) of a dead leaf.

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Wings are patterned on black-brown with white and orange markings. The fore wings have a distinctive squared off, hook-like (falcate) tip. Caterpillars appear humpbacked, having a small head, swollen first and second abdominal segments, and a last abdominal segment that is tapered and rounded. They are dark green with yellow stripes along the top and sides of the body, and have two black tubercles on the top of the thorax. Snout butterflies are known for their mass migrations which occur at irregular intervals when populations explode in the south and southwest. They may become so numerous as to darken the sky. One of these migrations was reported south of San Antonio in mid-September, 1996, where countless butterflies were observed flying northward.

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Now that’s a snout! And the scales look pretty cool, too.