American Snout Butterflies Inundate South Texas–enroute to San Antonio, Austin?

Butterfly listservs were all aflutter this week with news of butterflies inundating South Texas.  The American Snout butterflyLibytheana carinenta, arrived en masse in Brownsville and McAllen this week, firing up Facebook, Twitter and email lists with tales of snout butterfly overload.  “American snout butterflies swarm into the Valley,” reported the Brownsville Herald this morning.

American Snout Butterfly, photo via wikipedia
American Snout Butterfly, photo via wikipedia
“Clouds of those butterflies,” Carina A. Wyant Brunson posted on Facebook from McAllen, Texas.  “It’s hard to walk without bumping into one.”
Dalia R. Salinas of Brownsville relayed that she was sitting outside with her granddaughter “when all of a sudden a swarm of butterflies flew right in front of us. It was amazing, and to see my granddaughter’s face light with amazement was so delightful.”
We had an American snout outbreak in San Antonio in the summer of 2006. The migrating masses clogged car grills, gummed up windshields, and massed on local asters, dogwood, goldenrod and anything else bearing nectar.  There’s a good chance they’re coming our way again soon.
The mottled grey insects disguise themselves as dead leaves when their wings are closed.  In an open-winged pose, they flaunt orange, black and white accents.   They lay their eggs on hackberry trees, a drought-tolerant native considered a trash shrub by some.   But the hackberry is actually a fantastic wildlife plant.  Its leaves provide food for
Hackberry tree
Hackberry, beloved by the American Snout butterfly, photo via Texas A&M
Snout caterpillars and its berries offer important winter sustenance for birds.  The large numbers of migrating Snout butterflies can completely defoliate a hackberry tree, but  “It’s nothing to worry about,” said Michael Nentwich, Forester for the City of San Antonio.   “The trees will recover.  These are seasonal things that happen.”
This year’s weather pattern has lent itself to a butterfly boom, as we’ve written before.   And with temperatures rising earlier in the year, it makes sense the Snouts are arriving in June, rather than August, as they did last time.
In the annals of American Snout butterfly migrations, 1921 ranks as a most remarkable year.
I brake for butterflies via
After a world record downpour in Central Texas on September 9-10, 1921, when 36.4 inches of rain fell in an 18-hour period, a Snout butterfly breakout resulted a few weeks later.   “An estimated 25 million per minute southeasterly-bound snout butterflies passed over a 250 mile front from San Marcos to the Rio Grande River,” according to Austin entomologist Mike Quinn’s website Texas Entomology, a trusted and entertaining  source for Texas insect news and info.  Scientists noted at the time that the butterflies’ flight “lasted 18 days and may have involved more that 6 billion butterflies.”

Wow.  So no complaining if a few of the migrating insects get hung up in your car grill.  And remember to brake for the butterflies.

8 Responses

  1. Kathy Abbott
    | Reply

    Visiting Frio River at 7 Bluff and have seen a steady stream of American Snouts for 2 days… Guessing hundreds of thousands or perhaps millions. Truly amazing! September 6 , 2016

  2. Lisa
    | Reply

    Can someone please tell me why these American Snouts migrate south to north in the fall when almost everything else migrates north to south? What’s the deal??

    • Karen Dunning
      | Reply

      They don’t follow predictable migration patterns like monarchs do, Seiboldt says. They just follow their nose…err stomach.
      “They’ll come through, feed and they’ll move to the next area where there’s less predators more food,” from recent article about butterflies on your windshield San Antonio

  3. Lisa
    | Reply

    Snouts are coming through San Antonio! They’re swarming over my house right now. Too cool!!

  4. john
    | Reply

    Snouts have been hitting Austin over the past week with numbers building till yesterday they exploded! They were everywhere! Thickly streaming from Southwest to Northeast. Hopefully more today…….Now if we could just have a Monarch Migration. I’ve not seen any sign of a Monarch Migration in Austin in 2012.

  5. Ken Rivard
    | Reply

    Hi, Monika–
    Here I was, all fired up to congratulate you on that great shot of an American Snout when I see it’s from Wikipedia. Oh, well. I wish there were someone monitoring the Boston butterfly situation like you are the San Antonian one – I feel like I know more about Texan flora and butterflies than I do Massachusetts. Anyway, interesting post, and nice to read some good news about butterflies for a change, even if they are from Texas. Ken

    • Monika Maeckle
      | Reply

      Thanks, Ken. You guys should be swimming in Red Admirals these days. Let us know.

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