Genista Moth Caterpillars Return to Llano River Mountain Laurels

Last May I posted a much-read report of an extreme outbreak of Genista Moth larvae on two treasured Mountain Laurel trees my family had transplanted to our Llano River ranch 10 years ago.

The post, “Squish remorse” — Genista Larvae on Mountain Laurels Create Caterpillar Quandary,” started like this:

“It was an odd day, digging up wild parsley in search of chubby, Eastern Swallowtail caterpillars for fostering and fun at home, followed by hours of trying to figure out a humane and responsible way to kill hundreds–no, thousands–of unwelcome critters decimating several precious Mountain Laurels.”


The Genista Broom moth caterpillar, Uresiphita reversals, occupied almost every leaf of the tree.   Sometimes called the Sophora worm, these moth larvae relish the toxic leaves of our native Texas Mountain Laurels, Sophora secundiflora.


Genista moth caterpillars returned to a different set of Mountain Laurels this spring. Photo by Monika Maeckle

A year ago, the voracious caterpillars were decimating the evergreen native, which produces a Kool-Aid perfumed bloom that typically signals the first days of spring.

At the time, I was concerned the ubiquitous caterpillars would kill the tree or prune it to a shadow of its former self.   Several sources assured me not to worry—it was all part of the life cycle.

Twelve months later, I’m happy to report that the Mountain Laurels in question have rebounded magnificently. See the photo below.

Mountain Laurel

Genista moth caterpillars decimated this Mountain Laurel last year, but the tree bounced back nicely in 2014. Photo by Monika Maeckle

That’s the good news.

The bad news: the Genistas have  moved on to devour another Mountain Laurel further up the hill from their 2013 feast.   As Sandra Schwinn commented at the time:

“I have dealt with these for the last couple of years…. If there were just a few of them, it wouldn’t be so bad. Be prepared for a second onslaught, as that’s been my experience. In fact, last year, I battled them from spring into fall.”

Sounds about right.   While it’s reassuring that the caterpillar onslaught doesn’t appear to kill the plant, it does rob us of the next year’s purple blooms since Mountain Laurel flowers only occur on second year growth.

Genista Moth caterpillars

Genista Moth larvae returned to different Mountain Laurels this year on the Llano River. Photo by Monika Maeckle

Given the apparent heartiness of the Mountain Laurel I will resist the urge to squish the Genistas, letting nature take its course and ceding their role in the food web as fodder for lizards, wasps and others.

Related posts:

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How do Caterpillars Move? They Go with Their Gut–A Unique Form of Locomotion and a Crazy, Amusing Crawl

The caterpillar stage of a butterfly’s life is as interesting–sometimes moreso–than that final phase, when it unfolds its wings and takes first flight.   To witness eclosion, the moment when the chrysalis becomes a butterfly, is without a doubt magical.

But just as endearing is watching caterpillars move, wobbling, crawling, and creeping on flowers turning their expressive filaments and twisting  torsos like trapeze artists at Cirque de Soleil.

Given that caterpillars have no bones in their entire bodies, not even the crisp ektoskeletons of  insects like roaches or beetles, it’s hard not to ponder:  how, exactly, do caterpillars move?

Sphinx Moth caterpillar on Jimsonweed

Look for Tobacco Hornworms on Jimsonweed and your tomato plants

Turns out they go with their gut.   Literally. A groundbreaking study conducted last year in which scientists have the  intriguing critters walking on treadmills while x-rays scanned their wormy bodies indicated that the first step in a caterpillar’s stroll is taken by its gut.

Scientists observing the Manduca sexta, or tobacco hornworm caterpillar via X-ray learned that when caterpillars walk, their guts move first, with the rest of their bodies following behind in a rippling motion.  Think of one of those wave perpetual motion machines.

A caterpillar  “can burrow, it can climb, it can navigate through complex terrain,” said biologist Barry Trimmer and his team at Tufts University, who are fashioning soft bodied robots designed after the Tobacco Hornworm.

Caterpillars are everywhere right now with the warm, wet winter.  Just look under leaves and in lush growth and you’re likely to find one.  When you do, check out those moves, you’ll be amazed and delighted.

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Butterfly FAQ: Pros and Cons of Tropical Milkweed and What to do with a Winter Monarch Butterfly Caterpillar or Chrysalis

Several emails like the one below landed in my mailbox this week seeking counsel on what to do about late season Monarchs.

Hi Monika,

My friends found seven Monarch caterpillars on a well- protected piece of milkweed.  Six are gone, but one spun a chrysalis that they are protecting.  Do you have any advice?  We are wondering how long it will be in the chrysalis state in the winter.  Thanks for any advice you can give.


I would bring it inside, Dale–but that’s just me.

Usually it takes 10 – 14 days to eclose, or become a butterfly, but cooler temps can extend the process.  Caterpillars I

Monarch caterpillar makes its "J" shape and readies to form its chrysalis, 12/21/2011

Monarch caterpillar makes its "J" shape and readies to form its chrysalis, 12/21/2011 in my kitchen.

found on potted milkweed in mid December and brought inside hatched just last week and flew off on a warm 70-degree afternoon. But it could easily have gone the other way, with an ice storm hitting just as my butterflies hatched.  Then what?

Deciding whether or not to adopt in-process butterflies during the off-season always presents a quandary. Questions to ask:

  1. Do you have nectar available? Newborn butterflies generally don’t need to eat for the first 24 hours, but then they’ll need sustenance.
  2. What about host plants?  A butterfly’s first priority is to mate (for males) and lay eggs (for females) on their specific host plant.
  3. Will the weather cooperate?  Butterflies don’t fly when it’s less than 65 degrees.  Most will die with a freeze.

With our crazy Texas weather, Monarchs and other butterflies can hatch throughout the year depending on temperatures and host plant availability.  As noted last week, Monarchs are reproducing regularly on the San Antonio River — even into January.   Whether or not the eggs of those late season couplings make it to the butterfly stage is a crap shoot dictated by Mother Nature.

Monarch chrysalis about to hatch in my kitchen

Monarch butterfly about to hatch in my kitchen

Generally, if I have host plants, I take found caterpillars into my kitchen to increase their chances of becoming a butterfly.  Studies suggest that  caterpillars and eggs left entirely to nature have a 10% chance of becoming a butterfly.  When we lend a hand the odds are flipped–with a 90% chance.

What’s sad is when butterflies hatch and enter a world with no potential mates, no nectar and no host plants.   I once bought several chrysalises at Butterfly World, the Disneyland”

Tropical milkweed on San ANtonio River Walk

Tropical milkweed on the San Antonio River Walk 1/04/2012

of butterflies and a worthy destination for butterfly fans in Coconut Grove, Florida.  I returned to Texas in mid December with Luna and Polyphemus Moth cocoons, and a Giant Swallowtail chrysalis.

I pinned each to the curtain of my kitchen window as directed, providing the bright light that can speed up development.

The Luna Moth hatched beautifully and was released on a relatively warm January evening.  The Polyphemus Moth never hatched.   When the Giant Swallowtail eventually eclosed–about six weeks after purchase–an ice storm raged outside.  A week of cold and freeze followed.  The poor creature flailed around on my kitchen floor, refusing the cut flowers and diluted Gatorade I offered via Q-Tip. After three sad days, the Swallowtail perished.

For Monarchs, this may not be a problem if you have milkweed growing year round. The non-native but easily adapted Asclepias curassavica, sold in many nurseries as Tropical milkweed, provides nectar and host plant material and grows gregariously in pots that can be moved in and outside.

That said, some Monarch scientists, including our friend Dr. Lincoln Brower, worry that cultivating Monarch butterflies on Tropical milkweed year round can result in undesirable colonies of Ophryocystis elektroscirrha, or OE, a protozoan disease that infects Monarchs and other milkweed feeders. OE is present in the landscape but seems to especially flourish on Tropical milkweed in southern climates late in the year.  In colder climates and the wild, milkweeds die off in the winter, apparently purging OE to a large degree.

Scientists speculate that local OE-infested Monarchs will breed with migrating populations, possibly jeopardizing the migration.  Butterfly breeders and enthusiasts argue that OE is like staphylococcus–present in our populations and getting out of hand only under stressed circumstances.  Some believe that OE is simply a part of the evolutionary cycle, killing those butterflies less fit than others.

The answer, Dale, is that it’s a cold, cruel world for butterflies caught in flighty Texas winters–and an uneasy call for butterfly fans seeking to lend them a hand.

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Butterfly Plant Walk, Monarch Talk and Caterpillar Crawl to Kick off San Antonio Botanical Garden’s Amazing Butterflies Exhibit

The San Antonio Botanical Garden celebrates the whole life cycle with the aptly named “Amazing Butterflies” exhibit, an interactive nature maze created by London’s Natural History Museum in collaboration with Minotaur Mazes.   The exhibit kicks off this weekend with special events and will run through January 8, 2012.

Amazing Butterflies aims to give visitors a chance to experience the challenges of being a caterpillar by wandering through a nature maze of larger-than-life leaves, grass and trees before morphing into a butterfly. Enroute, participants learn how caterpillars move, what they eat and how other creatures help them during their life cycle. Ultimately, participants have the chance to flap their wings and even do a wacky dance–maybe like the one in the video above?  (Apologies to old friend Kim Wilson and the Fabulous Thunderbirds.)

“The timing of Amazing Butterflies couldn’t be better, since fall is when our local butterflies are most active and people can watch their magical life cycle unfold in their own backyards,” said Bob Brackman, executive director of the San Antonio Botanical Garden.  “And what a bonus that the fall is when the Monarch butterflies are migrating through San Antonio.”

Of course, you don’t have to convince the Texas Butterfly Ranch that butterflies are amazing.  We know it.  That’s why I’ve signed up to talk about Milkweed, Monarchs, Migrations and More* at 11 AM on Saturday at the exhibit.  Hope to see you there.

Opening weekend activities run 10 am – 2 pm this Saturday and Sunday and include butterfly workshops for children and adults, children’s arts and craft activities, live butterfly tent, and more. The Austin Bike Zoo will make an appearance with their much lauded amazing butterfly bicycles, offering rides and fun.

10:00 am Butterflies & Plants Walk
Patty Leslie Pasztor, Naturalist & Horticulturist
Wisteria Arbor
11:00 am Milkweed, Monarchs, Migration & More
Monika Maeckle, Texas Butterfly Ranch
Auld House
11:00 am  Storytime: Emily’s Butterfly Bouquet
Children’s author Kathy Luders. Book signing until 1 PM
Auld House Patio
1:00 pm Build it and They Will Come
Norman Winters, Executive Director, NABA National Butterfly Center
Auld House
10:00 am Butterfly Gardening
Diane Lewis, Horticulturist
Auld House
11:00 am  Storytime: Emily’s Butterfly Bouquet
Children’s author Kathy Luders. Book signing until 1 PM
Auld House Patio
1:00 pm Build it and They Will Come
Norman Winters, Executive Director, NABA National Butterfly Center
Auld House

*If the Monarchs are out, we’ll do a demonstration on how to tag them.  Join us!

The San Antonio Botanical Garden is located at  555 Funston Avenue in San Antonio, TX  78209.  Amazing Butterflies exhibit continues through January 8, 2012.  Access to the exhibit is free with paid admission to the San Antonio Botanical Garden–$8 for adults; $6 for students, seniors, and military; and $5 for children age 3-13. Botanical Society members enjoy free admission.



Butterfly Garden: Jimsonweed Takes the Heat, Sports Elegant Flowers and Hosts the Endearing Sphinx Moth

With its elegant white trumpet flowers, spiny seed capsules, and fragrant evening blooms, Jimsonweed ranks as one of my favorite butterfly garden plants.

The native datura inoxia partners well with another favorite, Cowpen Daisy.  Plant them together and you’ll have sprays of yellow and white blooms throughout the scorching summer, well into October.  Both plants gracefully defy our brutal heat, need little water or care, resist disease and pests and attract butterflies and moths.

Jimsonweed climbs to three feet and spreads an equal distance.  It creates a handy shady mass that protects less sturdy plants.  Up until this past week, Jimsonweed’s shade shielded verbena from frying and saved my tropical milkweed, too.  The plant is versatile, attractive and easy-to-grow.

Jimsonweed bloom.  Do you see the caterpillar?

Jimsonweed bloom. Do you see the caterpillar?

What else does this member of the potato family have to offer? Its spiny seed pods provide an unusual garnish–or should I say gardenish?  The thorny balls would make delightful earrings, or at least play a starring role in an exotic ikebana flower display.  As summer wears on, the walnut-sized pods turn from green to brown, spreading seed wantonly in the garden, making this durable perennial almost impossible to defeat once established.  The lush, large leaves of Jimsonweed also exude a chocolatey smell when watered or handled.

Spiny seedpod of Jimsonweed

Spiny Jimsonweed seedpod dusted with caterpillar frass

Another bonus: the captivating Sphinx moth, whose large size and brazen daytime flying cause it to be confused with small hummingbirds, hosts on Jimsonweed.  Sphinx moth caterpillars have a reputation with tomato gardeners as the despised tomato or tobacco hornworm, which is beautiful upon close inspection.  Look for it in the photo of the Jimsonweed bloom, above.

Cowpen Daisy, Jimsonweed, milkweed and lantana
August butterfly garden: Cowpen Daisy, Jimsonweed, tropical milkweed, Texas lantana

Underappreciated Jimsonweed does have a down side.  As a member of the nightshade family, it contains tropane alkaloids, the same toxins as belladonna, used in ancient times on poison-tipped arrows.  All parts of  Jimsonweed are poisonous.  Native Americans used the leaves as a painkiller and as an hallucinogen.   

Recent reports have reckless teens using Jimsonweed as a cheap high, but they should beware.  Hospital stays, even death, can result.

Jimsonweed’s namesake may represent one of the first instances of ethnobotanical warfare in American colonial history. Amy Stewart explains in her delightful book, Wicked Plants, that in Jamestown, Virginia, in the late 1600s, “British soldiers arrived to quell one of the first uprisings at the fledgling colony and the settlers remembered the toxic plant and slipped datura leaves into the soldiers’ food.”

They survived, but hallucinated severely for eleven days, giving Virginia colonists a temporary upper hand.   The assisting plant became known as Jamestown weed, and later, Jimsonweed.

Butterfly FAQ: Is Relocating a Monarch Chrysalis OK? Yes, and Here’s Tips On How to Handle Them With Care

A common quandary when blessed with the gift of caterpillars noshing nearby is whether or not it’s safe to relocate them once they form their chrysalis.

Tom Pelletier of the Ask A Naturalist website wrote today, explaining that six gorgeous Monarch caterpillars were busy at work on a milkweed plant in a yard adjacent to a high traffic sidewalk.

“Once the chrysalis is formed, can we move each one to a safer location in our back yard? Does it matter where the butterfly emerges, i.e.  does it have to be on milkweed?”

Monarch and Queen Chrysalises taped to Kitchen Counter

How do you think these Monarch and Queen chrysalises got here?  They’re adhered with tape.

The answers are yes, you may relocate the creatures once they make their chrysalis, and no, the caterpillars do not need to chrysalis on milkweed.  In fact, Monarch and other chrysalises often are found as far as 30 feet from the hostplant where they ate their last meal.

Entomologists speculate that caterpillars leave their host plants to protect themselves from predators.  “Caterpillars frequently strip the plant, so to form a chrysalis on a naked plant would leave them terribly exposed,” said Mike Quinn, an entomologist and founder of the Austin Butterfly Forum.  My unscientifc theory is that caterpillars need a quiet spot to transform themselves into a completely different lifeform. Growing wings and planning your first flight must require deep concentration.

Given the above, and the high incidence of caterpillar mortality caused by birds, spiders and other predators, I would be inclined to bring those caterpillars inside to assure they have the best chance of completing their life cycle.  You can feed them milkweed leaves and keep them in a clean container, then relocate the chrysalises once they’ve formed.

Jiminy Chrysalis!  Monarch and Queen Chrysalis Tree.  Thank you, dental floss.

Learn more about rearing Monarch butterfly caterpillars at the Monarch Watch website.

Those of us who raise caterpillars in our kitchens and gardens have been known to use pins, tape, glue, fishing line–and dental floss, my favorite–to fasten chrysalises to twigs, coffee stirrers, chopsticks, potted plants,  even the kitchen cabinet.

Why do we do it?   To ensure their completion of the life cycle is one reason.   But it’s also one of the most rewarding aspects of “butterflying.”  To witness eclosure, the moments surrounding a butterfly’s emergence from its chrysalis, is always magical.  The only way to do that is to have the chrysalis in captivity, where you can monitor its progress and not miss the miracle of metamorphosis.

When relocating a chrysalis, keep in mind:

1.  Putting them in direct sun–a hot window, for example–can damage their development.  A bright, protected spot is best. 
2.  Monarchs and other species need to hang vertically so that when they eclose, gravity can assist in their wings forming properly.   Swallowtails are different.  Try to emulate the chrysalis’ natural positioning as much as possible.
3.  Once the butterfly emerges, it needs several hours before it can fly. If you’ve brought it in the house to watch, leave the newborn alone until its wings harden up and it starts beating them slowly.  Then you can release it outside.
Eastern Swallowtail and Sister Chrysalis on a Chopstick

Eastern Swallowtail Butterfly and Sister Chrysalis adhered with nontoxic glue to a Chopstick.

An excellent resource for relocating chrysalises and reattaching them without causing harm is Shady Oak Butterfly Farm.   Edith Smith, butterfly meistress, and a member of the International Butterfly Breeders’ Association, has been raising butterflies for decades and graciously shared the useful links below.  Thank you, Edith!

1.  How to move/relocate chrysalises
2. How to adhere chrysalises with glue
3. What to do if a soft chrysalis falls
4. How to reattach a swallowtail chrysalis
For more info on this topic, check out our post on How to Move a Monarch Chrysalis.

Beating the Bushes Takes On New Meaning After Caterpillar Crawl and Lecture by the Effusive Dr. David L. Wagner

“They enrich our journey and make every day more interesting.”

That’s how Dr. David L. Wagner, Professor of Ecology and Evolutionary Biology at the University of Connecticutt, began his talk Monday evening at the Austin Butterfly Forum. His audience of about 70 wouldn’t disagree after watching his entertaining and educational presentation.

Caterpillars of North America

The author of Caterpillars of Eastern North America itemized the many reasons we should care about caterpillars (or butterflies-to-be, as I like to call them).

Apart from their aesthetic contribution of morphing into the lilting butterflies we know and love, caterpillars are the “fabric that tethers the terrestrial communities” that keeps our forests and wildscapes whole, says Dr. Wagner.  They’re also “the hamburger of the animal world.”

Grizzly bears in Yellowstone Park have been observed consuming 20,-30,000 moths per day and a robin was documented eating 165 caterpillars in a single 24 hour stretch–more than twice its bodymass.  And the bats that emerge from Austin’s Congress Avenue bridge?   Each evening between March and November, the flying mammals consume 10,-20,000 insects, “mostly moths,” says Dr. Wagner.  Where would all these creatures be without caterpillars?

Birdwatchers are well aware of the consequence of caterpillars. They are the preferred grub of many songbirds.  Dr. Wagner pointed out that caterpillar enthusiasts often begin as birders since watching birds leads one to track their food source: caterpillars.

Caterpillars are also pollinators and responsible for the silk shirts and sheets we enjoy (thank you, silk moth!).   Some species are the janitors of the wild, eating and cleaning up dead leaf matter.   One of the lesser known imports of caterpillars is how they play a big-but-indirect role in our daily lives by exerting a “chronic force” on plants to evolve defense mechanisms to discourage being consumed by them.

“Plants are immobile.  Caterpillars are omnipresent,” says Dr. Wagner.  Plants have adapted to that by evolving strong, often distasteful flavors like caffeine, latex and capsaicin to deter their consumption.

Coffee, tea, latex, aspirin, the tannins in red wine, cinnamon, pepper, and many other spices all result from plants’ reaction to caterpillars.  “In a roundabout way, life would be considerably less rich and less interesting (and much less flavorful) without caterpillars,” said Dr. Wagner.

Dr. Wagner showed dozens of amazing and entertaining slides of caterpillars in various contortions and camouflage–posing as sticks, pretending to be flower buds–but the biggest laugh came when he described a peculiar habit of a cute yellow-and-brown caterpillar that morphs into a lovely brown butterfly.

The silver spotted skipper, not uncommon in Austin and San Antonio, apparently practices the habit of “ballistic defecation”–shooting its excrement up to 153 centimeters from its body.  The trick throws off predators by spreading its scent far and wide.

Sunday morning a handful of Austin Butterfly Forum members were treated to an entertaining walk in the woods at the Barton Creek Greenbelt in Austin.  Grabbing our “beating sheet” we tackled the dry riverbed, discovering myriad insects, but not a huge haul of caterpillars, thanks to the drought.  For a proper demo of bush- beating technique, see the video, above.

Dr. Wagner recommends carrying a magnifying glass or lens to better observe the fascinating creatures.  “Caterpillars are little mysteries.  Much of the time you are not sure how they will turn out,” he says.  

Which surely contributes to their charm.