UVALDE – The Return of the Snouts. Shadow of a Snout. Bravesnout. If the recent resurgence in Texas of one nature’s “nosiest” representatives was to be given a movie title, one of these might do.
Many areas of the Lone Star State are once again being invaded by swarms of Libytheana carinenta, more commonly know as the American Snout butterfly, said Dr. Noel Troxclair, Texas AgriLife Extension Service entomologist in Uvalde.
“There are tens of millions of these butterflies in this particular surge of activity,” said Troxclair, who works at the Texas AgriLife Research and Extension Center.
Large numbers of American Snouts have been spotted throughout the Central Texas corridor from Del Rio in the southwest to San Antonio, the Hill Country and Austin in South Central Texas.
“This likely will not be as large as the 2006 snout emergence, but they’re still causing a stir among people in this region,” he said.
Troxclair said the butterflies also are causing some grief among drivers living in or passing through the region who have to scrub them off windshields, hoods, grills and radiators.
He added that apart from their effect on humans, especially their literal impact with their vehicles, the butterflies do not have much of an impact on the environment.
Drought has been a major factor in the American Snout population explosion this year.
“Early drought conditions led to a lack of parasites, predators and pathogenic organisms that typically reduce the snout population,” Troxclair said. “This has allowed them to reproduce in far greater numbers.”
The primary host for the American Snout is the spiny hackberry, but they sometimes feed on other hackberry species, Troxclair said.
“Snouts can defoliate these trees, but the trees typically grow leaves back quickly so there is no permanent damage,” he said.
The butterflies are not in the midst of a monarch-like migration but more of a northward “dispersal migration,”said Dr. Bart Drees, AgriLife Extension entomologist in College Station.
“Basically they travel from south to north, but there’s no clear path like with the monarch butterflies,” said Drees, author of A Field Guide to Common Texas Insects. “They move as a mass but don’t have any particular destination. Basically, they’re on a road to nowhere.”
Drees said in past years dispersal migrations of the American Snout in South and Central Texas have been thick enough to obscure the sky.
He also noted that the American Snout is “not considered one of most attractive among the butterfly species.”
“But their beauty isn’t always obvious because they’re brown and when they land in the hackberry trees they’re well camouflaged,” he said. “The upper side of the wings are a dull orange, the wings have a distinctive, squared-off, hook-like tip and they have rather prominent elongated mouth parts that give them their name. I guess you could say they have a face only an entomologist could love.”
For more information about snout butterflies, visit http://insects.tamu.edu/fieldguide and click on Lepidoptera. Also visit http://www.texasento.net/snout.htm.