Fall Butterflies in Houston

Last week I gave a workshop/lecture at the Houston Arboretum about “Butterflies of Houston.”  I had not chosen the title, and confess I was a little nervous about the emphasis – I can hold my own talking about butterflies in general, and especially about Central American butterflies, but I am not an “expert” on the local species.  Especially not the “LBJs” (little brown jobs; mostly skippers) of the butterfly world!  However, I put together my slides and gathered some field guides and hoped for the best.

It was a fun class.  The participants (regrettably, only about 9 people) were interested, knowledgeable and enthusiastic about their own butterfly gardening and viewing attempts.  We decided to go ahead with the scheduled field trip on Saturday even though the weather prediction was for possible rain.

spicebush swallowtail larvae
Spicebush Swallowtail Caterpillar.

It was overcast but not raining as we gathered in the Arboretum parking lot.  No butterflies were flying, but one of the participants quickly pointed out a smallish camphor tree that had the characteristic rolled leaves housing my favorite caterpillar, the spicebush swallowtail.  These adorable creatures look like toy snakes – they are bright green with large eyespots on their thorax.   A discussion ensued as to why some of the participants had never had spicebush caterpillars on THEIR camphor (or sassafras) trees.  We concluded (or at least I concluded) that the female butterflies really seem to seek out small trees – young saplings, not mature trees.  Perhaps the young trees haven’t yet upped their levels of caterpillar-deterring chemicals, or perhaps their leaves are more tender.  Or perhaps the caterpillars are simply harder to find on larger trees.  And besides, the butterflies really do seem to prefer the hostplant they are named for – spicebush (Lindera benzoin) – but it really doesn’t do all that well in our area.  In any case, I have noticed the same pattern (more caterpillars on small/young plants) in the citrus-feeding giant swallowtail as well.

Not finding much more in the parking lot, we wandered down the Outer Loop trail to the Meadow.  I had hoped to see a few forest butterflies such as tawny, hackberry emperors, red admirals, or even goatweed leafwings, along the Loop Trail, but no such luck.  However, soon after arriving at the Meadow, I was very excited to find caterpillars of the goatweed leafwing on the Texas goatweed (Croton capitatus, aka hogwort or woolly croton) plants growing abundantly along the roadside edge.  Like spicebush caterpillars, these guys hide in rolled up leaves of their hostplant during the day.  However, in contrast to the whimsical spicebush cats, leafwing catepillars are rather drab, greenish with whitish bumps on the body, and a slightly warty, dark head.  And, they spit copious amounts of bright green fluid when you try to unroll them!  I complained to my companions that I had just pulled two large goatweeds out of my garden after waiting all summer for caterpillars!  Perhaps I had given up too soon, or perhaps one needs to be closer to a forest habitat as a source of the egg-laying females.  Who knows? (This could be tested, however, if someone wanted a definitive answer!)

gw leafwing frass chain

But back to the caterpillars:  another cool thing about leafwings is the unique “frass chains” that the caterpillars make when they are very small.  This damage is also characteristic of tropical members of this family, and I have seen it often in the field – often the first clue that a caterpillar is on a given plant.  What IS a frass chain?  First of all, you should know that “frass” is the technical (and very nice, I think) word for “insect pooh.”  The tiny caterpillars eat the tip off a leaf, leaving just the midvein.  They then use their silk (all caterpillars have silk-producing glands in their mouths) to glue tiny pieces of their excrement (frass) to the end of the midvein, elongating it by as much as ½” (it helps to have a hand lens or magnifying loupe to see this).  They also sometimes glue random bits of dead leaf material along the midvein higher up.  Then, during the day, the little caterpillar, which is about the color of a dead leaf bit itself, sits at the end of the frass chain, hidden in plain sight.  So clever!  When it gets larger it moves into a rolled leaf (also held together with a bit of silk).

gulf fritillary Agraulis vanillae
Gulf Fritillary, Agraulis vanillae.

We then noticed the much showier, spiny black and orange caterpillars of the most common butterfly we saw that day, the spectacular gulf fritillary.  Gulf frits, like all members of their subfamily (the longwing or passionflower butterflies) eat passionflower vines as caterpillars.

caterpillars
Gulf fritillary caterpillars on passionflower vine

And there was plenty of the native Passiflora incarnata, or maypop, growing in the Meadow.  The butterfly itself is one beautiful bug, especially the males, which, like many other butterflies and songbirds, are more brightly colored than females.  Males are a brilliant orange above, with a few black spots; females are similar but a duller orange.  The underside of both has sunrise-like hues of pinkish orange on the upper wing, and spots of silver (yes, silver!) spots spangling the lower surfaces of both fore and hind wing (rendering the butterfly very difficult to see when perched in the vegetation).

buckeye cat

We also saw several buckeyes, one of our prettiest butterflies, with large eyespots and multi-colored patterns in brown, purple, orange, and blue on the upper wing surface.  The underside is quite drab and cryptic – it is hard to imagine it is even the same butterfly (but this is true of most butterflies, that the underside is drab or camouflaged no matter how showy the upperside).  We found buckeye caterpillars too, blackish and spiny, easy to see on the slender upright stems of their hostplant, Agalinis fasciculata or false foxglove.

I was determined to identify some skippers, even though this large group of mostly small, mostly brown, mostly very fast-flying butterflies had heretofore been a bigger challenge than I wanted to take on.  But I had my reputation to uphold!  We did come across several individuals, and luckily the group was patient as I flipped through the field guides.  Eventually we managed to identify to all of our satisfactions the skippers we saw, including a clouded skipper, an ocala skipper (we think), and a fiery skipper.  Much easier to ID was the showy (in skipper terms) white-striped longtail – the brilliant white stripe on the underside showing clearly when it perched to sip from the lavender blazing star (Liatris) or ironweed (Vernonia) flowers blooming profusely in the Meadow at this time.

scoliid waspWe did not see any blues or hairstreaks (well, I saw a tiny Ceraunus blue and a gray hairstreak after the group had left) but we did see several other interesting insects.  A pretty scoliid wasp – metallic black with bright creamy white spots on the abdomen – was very interested in the abundant flowers of late-flowering Boneset (Eupatorium serotinum). This native plant looks like a weed except when it is blooming, as it does only at this time of year.  Its tiers of small, fuzzy, white, fragrant flowers attract many small butterflies, especially hairstreaks and skippers, along with other insects including wasps, flies, and ermine moths.  On the goatweed we encountered several groups of a funny little bug (a hemipteran, or true bug) that looked much like a Volkswagon beetle.  The nymphs were gregarious, huddling in groups of 5-8 individuals.  When we disturbed one group, they followed each other in a little train until they found a new place to rest. 
goatweed bugs

Finally we saw a really big butterfly – the powerful and dramatic spicebush swallowtail, which we were able to identify on the wing (it never landed) as a male because of the greenish (rather than bluish) wash of scales on the upper side of the hind wing.  A gorgeous butterfly.  On a sunnier day we might have seen other swallowtails – probably giants, possibly pipevines, perhaps Tiger swallowtails, which I have seen at the Arboretum on other occasions.

Carlos Hernandez
Male Spicebush Swallowtail Butterfly.
Photo by Carlos Hernandez.

In sum, although we didn’t see hordes of butterflies, we all agreed it was a pleasant and productive outing, and finding all the caterpillars bodes well for the coming weeks.  After our relative success identifying skippers, I am ready to get out on a sunnier day when more are flying – and tackle more species!

Note:  If you are interested in watching butterflies, you should invest in a pair of close-focusing binoculars.  These are now widely available.  The difference between regular binoculars and these is that the closest you can focus with regular binoculars is about 10 feet or so – with close focus you can get to within 4 feet of your subject.  This is especially useful for observing small things like insects.  Both kinds are equally good for focusing on things far away, so you don’t lose anything by choosing close focus.

You will also want a field guide or two.  Although not really a field guide, I recommend John and Gloria Tveten’s “Butterflies of Houston and Southeast Texas” – it has gorgeous photos of adults and often the caterpillar stage, and tons of good information about the habits and habitats of most of our local butterflies.  You should also pick up either the “Kaufman Field Guide to Butterflies of North America,” or Jeffrey Glassberg’s “Butterflies through Binoculars:  the East.”  These are much less detailed than the Tveten’s work, but are much more comprehensive (and useful not just in Houston). Those of you who really get into caterpillars will want a copy of David L. Wagner’s “Caterpillars of Eastern North America.”   This book has fabulous photographs of nearly 700 caterpillars of both butterflies and moths, with a small illustration of the resulting adult, and nice descriptions of where the caterpillars are likely to be found and what they eat.  And don’t miss Wagner’s wonderful enthusiastic preface and introduction, which include all sorts of fun and useful information.

The next few weeks should offer prime butterfly watching.  So get out there – on a sunny day almost any area with some natural habitat and blooming plants should yield butterfly results!

My love affair with the tropics (how and why I became a biologist)

 Our fearless leader
Dr. Larry Gilbert

My introduction to the tropics was in the summer of 1983, when I lucked into accompanying Dr. Larry Gilbert (UT Zoology) and his students on a field course to Corcovado National Park in Costa Rica.  Not being a student at the time (I’d gotten a BA in linguistics a couple years before but was working as a secretary on the UT campus), but having some proficiency in Spanish, I was hired by Dr. Gilbert as his assistant and translator since his regular teaching assistant was off making a film in New Guinea. 

After several weeks in Patterson Hall on the UT campus, translating documents and readying equipment, we left for Costa Rica, flying into the capitol, San Jose.  Here our party (5 graduate students plus Dr. Gilbert – Larry to his students – and myself) spent a couple of days at the “Costa Rica Inn” – a rambling one-story labyrinth of a hotel near the downtown area.  San Jose is a typical Central American city, with lots of traffic and pollution, no interesting architecture to speak of…but great ice cream and plenty of activity – and in those days, very safe at all hours.  We visited the Natural History Museum and the local university, picked up some supplies (foam mattresses and rum are what I remember!), and made our flight arrangements.  We were flying in to the park in two 5-seater Cessnas; there was no other access to the remote field site location. 

View of the Corcovado canopy from the plane.
Photo by Dr. Larry Gilbert.

The day arrived and we boarded the tiny planes.  I was quite nervous as I had never flown in such a small plane before, and the pilot warned us that it might be a bumpy ride due to rising air currents as we crossed the mountains.  And Larry joked about the two wrecked planes that decorated the end of the airstrip in the park… 

The flight took about an hour, and it was indeed turbulent.  Finally we flew out over the Osa Peninsula and saw nothing but forest below us, and then the Pacific Ocean beyond. We suddenly turned at right angles to the coastline to land at a tiny airstrip cleared in the rainforest, ending at the beach…and there, indeed, were the two wrecks.  Welcome to Sirena Station of Corcovado National Park!

We pitched tents in the clearing/horse pasture behind the rustic park station building; this would be our home for the next six weeks.  The students included Darlyne, studying heliconius butterflies; Kirk, studying the fish communities in freshwater streams; Jamie, studying howler monkeys, and Peggy and John, new students who had not yet decided on projects.  Two senior students, Peng Chai and Sue Boinski, were already in the park.  Peng was studying bird predation on butterflies.  “Bo” as she was called, was the equivalent of a mountain man, in my somewhat awed view.  She had spent the past several years following troupes of squirrel monkeys to learn about their behavior and mating habits, sometimes staying in the park for over a year at a stretch. In the course of her wanderings she had dodged fer-de-lance and bushmaster snakes, and had some (very shaky) video footage of a pair of jaguars lazily playing together, oblivious of their nervous human watcher. 

Fruits of the
Corcovado rainforest.
Photo by Dr. Larry Gilbert.

The Sirena station was a bustling place.  Since in those days (before the gold miner crisis of 1985) it served as the park headquarters, it was the central point in Corcovado for communications and supplies, which were all brought in by plane.  The park director was stationed here, along with about 5-6 park guards.  Other park guards travelling by horseback from the outlying stations came in to pick up their allotment of supplies, or to rotate out for a week’s holiday.  The radio crackled all day long:  “Sierra Papa Norte Dos a Sierra Papa Norte” (National Park Service station 2 to headquarters).  I learned all sorts of things in radio lingo – “Cambio” meant over, “Dos” meant good, “Dos y medio” was so-so, “Tres” meant bad, “un 22” was a telephone call, “10” was crazy, etc. 

The station in those days was rustic.  Electricity was provided by generator only at lunchtime and for a couple hours in the evening.  Running water was ingeniously piped in from a nearby stream.  Course participants and park guards all ate together in a little open-sided building:  generous portions of rice and beans, smaller portions of meat and vegetables, inventive desserts, and drinks made from fresh tropical fruits, all deliciously prepared by Maria, the feisty and attractive cook.

Buttress of a tropical giant.
Photo by Dr. Larry Gilbert.

The first few days Larry led his students and me on long, sometimes wild walks through the forest – up over the steep knife-edged ridges, crashing down through stream beds, slogging along the beach or sweltering through open areas.  What an amazing place!  I was in love with the forest from the moment I saw it.  So many plants – so many insects, birds, monkeys, frogs, snakes, etc.  But especially plants.  It was like being in the most amazing botanical garden.  Here things I’d only seen as houseplants grew rampantly everywhere.  Ferns were not just ferns but trees.  And trees, with their huge buttresses as big around as a house, towered into the canopy.

Squirrel Monkies are common
near Sirena

After a week or so of our introductory walks, the students settled down to their research projects.  Since I wasn’t a student and didn’t have my own project, I helped some of the others where I could.  I soon was spending most of my time with Kirk, helping him census the fish in the many small streams that cut across the peninsula – streams so clear and clean that we drank out of them.  I learned a lot about fish that summer!  At night, we all sat in the little screened porch behind the radio room, burning candles and mosquito coils while we read or wrote up our field notes, or listened to one of the students give a status report on his or her project.  Larry often regaled us with funny stories of his past students…considerably embellished over the years, I am sure!

 Tropical leaf-footed bug

All too soon the summer came to an end, and we had to leave the park and head back to Texas to begin the new semester.  We packed the tents and our supplies into coolers to keep out the mildew.  Said our goodbyes to the park guards and to Maria.  Cleaned up the area we had taken over as our evening “lab.”  While we waited for the planes to arrive I took a last walk up the Claro trail to a ridge where, sitting on the buttress root of a huge strangler fig, I could see over the forest and out to sea.  What an adventure it had been!  What a lot of amazing biology I had learned!  Nostalgia for the place swept over me – but I heard the drone of the plane and had to rush back to camp.  We boarded the Cessna, and as it rumbled down the bumpy airstrip and began to lift into the air, I thought – if the plane crashes on the way back, I will die happy.  I have just spent the most amazing summer of my life.

I ended up becoming one of Larry’s students and spending several more summers in the park and elsewhere in the tropics.  However, that first experience stays with me as one of the real highlights of my existence on this earth. 

 Ornate flower of a tropical passionvine
 Red-eyed treefrogs.

Before the Hurricane: Securing the HMNS Greenhouses

Red Beauty
Creative Commons License photo credit: jtloweryphotography

As many of you know, the greenhouses of the Cockrell Butterfly Center (CBC) are located on the rooftop of the parking garage on the seventh floor.  Two days before Hurricane Ike hit the Gulf Coast, my volunteer Penny and I were busy preparing the greenhouses for the upcoming storm.  Because we are a USDA regulated facility, we must adhere to specific guidelines in the event of a disaster such as a hurricane. 

The first task at hand was to safely remove the Heliconius longwing butterflies from the rearing facility and transport them into the CBC lower-level basement where they were temporarily housed in 3’X4’ zippered/framed insectaries.  Penny helped out with the transport of the precious little ones and carefully placed a few nectar sources into the three separate insectaries along with a bowl of artificial nectar source. 

Next, we had to remove the 600 caterpillars which were all at different stages of growth to a pupation cage which we transported to the basement by way of my truck-bed.  To our dismay, the pupation cage would not fit through the newly repaired door frame on the seventh floor so we rolled it down the main hall of the museum by way of the main entrance handicapped ramp.  Once we had the pupation cage in place, we transferred the 600 caterpillars into the cage along with a feast of Passionflower vines for them to feed upon until the storm passed. 

We were so busy doing the transport and removal that our Staff Entomologist, Laurie, and Soni, our Assistant Conservatory Horticulturist, came up to the seventh floor to help out by watering the other plants within the greenhouses. Nancy, our CBC director, and Erin, our Insect Zoo Manager and Entomologist decided that because they lived close to the museum, they would make sure that the little ones housed in the basement would be tended to as soon as they could get into the museum district to do so.

passionfruit flower
Creative Commons License photo credit: Meme!

In the greenhouse area, we spent all day removing all the projectile objects from the exterior (wood, concrete blocks etc.).  We secured the plastic tables that usually hold plants to the white fence with newly purchased ratchet straps.  The greenhouse shade screens are set up on a pulley system so we rolled them all down and secured them with the straps. 

Inside the greenhouse, we pushed aside the mist tent where we house our seedlings to make way for the 700-plus plants that were outside that had to come inside until the storm passed.  We also had shelves of thousands of plastic plant flats and thousands of plastic pots which had to be pulled into the greenhouses so that they wouldn’t fly all over from the high winds.  We removed the shade cloth from the exterior so that it would not get ripped up in the wind.  We also had cans full of  Osmocote, a timed released fertilizer, bone and blood meal, perlitevermiculite, soil-mix and orchid medium that we transported into the greenhouse.

Whew… what a day!  We left feeling good about having secured the greenhouses and hoped that when we returned that the greenhouses would still be there.

2008-09-15   15-47-08   IMG_2629
Creative Commons License photo credit: geocam20000

As I write this blog, there are still millions without electricity or water and lots of recovery is taking place in Houston and in my neighborhood, Katy.  The CBC greenhouses, I am happy to say, survived the winds and the rain.  Only one thing happened - two of the steel shade clothes decided to roll themselves backwards and ended up on the opposite side of the greenhouse but remained attached to the roof. 

Erin and Nancy cared for our babies in the dark basement with the aid of flashlights and for this I thank them.  Abraham, our groundskeeper, filled 55 gallon cans with water and Erin and Nancy hand watered the plants in the greenhouses.  There was no electricity in the museum until Wednesday afternoon - hence no elevator – so Abraham had to deliver the water to the seventh floor in the back of his truck.

Since then, we have returned the rearing pairs of longwing butterflies to the insectaries where as of yesterday, there was mating and egg-laying occurring - just as nature intended.   We hope that you are all faring well and wish only the best for you and your precious families.  If you do have a spot in your yard where a tree once stood, you may want to consider filling it with butterfly host plants and nectar plants not only for them, but also for the hummingbirds who will soon be migrating south and will stop in our yards to replenish their energy or to possibly build a nest. If you are able to, we hope you’ll join us for our Fall Plant Sale on Saturday, October 4 on the seventh floor of the parking garage, from 9 to 1 p.m. We would love to see you. 

Take Care…
Ory
 

Luxurious Longwings

Zebra Longwing
Creative Commons License photo credit: jtloweryphotography

Do you ever wonder what goes on inside the butterfly rearing greenhouseslocated on the rooftop of the museum’s parking garage? Today, I’m going to give you a peek at one of the precious little butterflies we raise there – the Zebra longwing, Heliconius charitonius.

Located within the screened insectaries inside the greenhouse are male and female pairs of Heliconius longwing butterflies. Within the confines of each Insectary, the longwing butterflies are provided a smorgasbord of goodies.

Their main food source is nectar, which is provided to them by way of fresh blooming red and pink Pentas; “New Gold” Lantana; pink Jatropha; blue Duranata; red, purple, and blue Porter Weed; and a blooming vine of Psiguria. These plants provide a food source (nectar and pollen) to the mating pairs. Our volunteers also place two bowls of artificial nectar daily as a supplement to the plants. [We supplement the food with artificial nectar made out of sugar and water because these little butterflies are housed in an artificial environment, so we want to be sure that they don't ever run out of food (nectar from flowers).]

Passion Flower (aka Clock Flower)
Creative Commons License photo credit: Hamed Saber

We have pipes within the enclosure on which baskets of the Zebra longwings host plant – The Passionflower – hang. Each week the Passionflower host plants are removed from the Insectary and placed into the pupation area. Within 3-5 days, tiny caterpillars hatch from eggs the female longwings have laid at the end tips of the passionflower vine. These tiny, soft, supple leaves are the tiny caterpillars’ first food source.

Within 17 to 21 days (depending on the time of the year), the caterpillar is ready to pupate. After the caterpillar pupates, the pupae are removed from the screen pupation cages in which they are housed and taken to our entomologists for gluing. They are then displayed in our Butterfly Center until the butterflies emerge. The entomologist then removes them from the emergence case and releases them to flutter around the rainforest.

There are hundred of school children and adults that tour the greenhouses every year and they are always excited to walk into the Insectaries and be surrounded by butterflies. Then, we take them to the pupation area to see the caterpillars in their different stages of growth. Finally, they see the pupation cages where the larger caterpillars are pupating. They hold the pupae, touch the butterflies and look at their scales under a magnifying glass. Visitors are always amazed to see the butterfly life cycle up close, and we are so glad we can give them the opportunity to do so.

Want to learn more about butterflies and host plants?
Attract Black Swallowtails to your garden.
Find out what to feed your Monarch butterflies.
Flutter after Giant Swallowtails.