100 years – 100 Objects: Jamaican Giant Swallowtail

The Houston Museum of Natural Science was founded in 1909 – meaning that the curators of the Houston Museum of Natural Science have been collecting and preserving natural and cultural treasures for a hundred years now. For this yearlong series, our current curators have chosen one hundred exceptional objects from the Museum’s immense storehouse of specimens and artifacts—one for each year of our history. Check back here frequently to learn more about this diverse selection of behind-the-scenes curiosities—we will post the image and description of a new object every few days.

This description is from Nancy, the museum’s director of the Cockrell Butterfly Center and curator of entomology. She’s chosen a selection of objects that represent the rarest and most interesting insects in the Museum’s collections,that we’ll be sharing here – and at 100.hmns.org- throughout the year.

Jamaican Giant Swallowtail – Papilio homerus

Jamaican Giant Swallowtail-4x6This swallowtail species, endemic to the island of Jamaica, is the largest butterfly in the western hemisphere.  Today it occurs only in two small, isolated populations of tropical rainforest and is considered endangered.  We have two males and a female in our collection.

Learn more about moths and their relatives in a visit to the new Brown Hall of Entomology, a part of the Cockrell Butterfly Center– a living, walk-through rainforest at the Houston Museum of Natural Science.

You can see more images of this fascinating artifact – as well as the others we’ve posted so far this year – in the 100 Objects section at 100.hmns.org

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!

Beautiful Spring-time Butterflies!

Spring-time is almost here and the butterflies will soon be fluttering all around town.  I have actually seen a lot already, but we do live in Texas, so that’s not a surprise.  Since I work in an exotic butterfly house, I definitely have my favorite exotic butterflies, but I also have a few favorites that are here in Texas as well.  Many of you may be expecting me to write about the monarch, Danaus plexippus, but I thought I would write about some different, but still very common ones that we find around here in Houston.  If you are interested in monarchs, please check out Nancy’s blog - all about monarch migration.

Morning Butterfly
Creative Commons License photo credit: Joel Olives

The Gulf Fritillary, Agraulis vanillae, is a butterfly that frequents Houston quite often.  Its caterpillars feed off of every single part of the passion vine plant, which make them poisonous and nasty-tasting to predators. 

A couple of summers ago, I had tons of these caterpillars on my passion vine plant.  The caterpillars have large spines along their body with an underlying bold purple, orange, and black coloration, serving to warn predators of their danger!  I’m sure many of you have seen this bright orange and black butterfly fluttering around nectar plants such as Lantana, Zinnia, Coneflowers, Butterfly Bush, and many others. 

One of the most distinct characteristics of the Gulf Fritillary is the spectacular silvery, almost mirror looking, spots on the underside of the wings.  The males and females look very similar, but the black stripes on upper side of the female’s wings are thicker and more pronounced.  Although this butterfly is not here in the Butterfly Center very often, take advantage of its beauty outdoors right here in Houston.  

The goldrim butterfly, Battus polydamas, is a member of the swallowtail family (Papilionidae), but it does not have the typical tails that many of these butterflies have.  The name ‘gold rim’ comes from the golden-yellow crescent shaped markings on the upper edges of both the fore and hind wing.  Caterpillars of this species are gregarious (living together) in the early stages but become solitary when older.  The caterpillars are a dark reddish gray color with paired fleshy tubercles along the back of the body.  

I am very fond of these cute caterpillars and was fortunate enough to take this adorable picture in our butterfly garden right outside of the museum.  Adults are mainly associated with disturbed areas of the forest and can be seen visiting gardens throughout the city.  They are nectar feeders and especially like Lantana.  Like many swallowtails, this butterfly flutters constantly while feeding instead of stopping to rest.  This butterfly is fairly common in Florida and South Texas and will at times stray to Kentucky and Missouri. 

Clouded Sulphur
Creative Commons License photo credit: tlindenbaum

Once spring-time hits, I seem to see this next butterfly all the time!  As a native of heavily populated areas such as parks, yards, gardens, and road edges, the cloudless sulphur, Phoebis sennae, can be seen almost anywhere along the gulf coastal states. It is characterized by its pure bright yellow to greenish-yellow wings. The males use strong rapid flight to search for a receptive female. The eggs are laid singly on leaves of Cassia,which the caterpillars happily consume, and hide underneath, to rest. The pupae are oddly shaped, compressed from side to side with a greatly distended “chest and belly”. They use a silken girdle to attach themselves to the leaf during pupation. These butterflies are harmless to plant life and are a welcome visitor to any garden.

One of the largest butterflies that I see around town is the Giant Swallowtail, Papilio cresphontesThis fantastic butterfly is native to large portions of North, Central, and South America. It very common in Houston and can be seen gracefully fluttering and sipping the sweet nectar of flowers such as Lantana, Azalea, and Honeysuckle.

Characterized by the striking diagonal yellow band across its forewing, and its long yellow-filled tails, this butterfly is a joy to see in one’s garden! The larvae feed strictly on citrus plants and are commonly called “orange dogs.” As a defense, they cleverly disguise themselves as bird droppings as they sit motionless during the day and feed at night. As with other swallowtails, these caterpillars’ posses a bright reddish orange, y-shaped gland called an osmeterium, which contains a mixture of highly noxious chemicals that smell like rancid butter. This gland helps to protect the caterpillar from small predators such as ants and spiders. The pupal stage remains inconspicuous, resembling a piece of tree bark.

These four butterflies are only a few of the wonderful butterflies that live in Houston.  If you are more interested in butterflies you should check out Butterflies of Houston & Southeast Texasby John and Gloria Tveten.  It’s a wonderful book and has amazing pictures.

Love Butterflies?
Bring them to your garden with scrumptious (to butterflies, anyway) host plants – available at our Spring Plant Sale April 4, 9 a.m. – 1 p.m. Stay tuned for more details!

Out in the garden

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For the past few weeks, the Cockrell Butterfly Center Staff and Dedicated Greenhouse volunteers have been busy enhancing the exterior Butterfly Demonstration Garden. The garden is located outside the Main Hall exit near the Cockrell Butterfly Center’s entrance doors. This garden comes complete with a stone path, an arch for a climbing Passionflower vine and lots of beautiful red, blue, yellow and white blooming nectar sources.  We also make available the host plants for the caterpillars to feed on. Permanently affixed to the center of the garden, sits a framed pictorial directory of host plants and nectar plants. We are in the process of updating the poster with some new species which we feel perform well for the garden and its all important visitors the delightful, graceful, jewels with wings.  If you want to see what a specimen plant that is listed on our Butterfly Gardening brochure looks like, this demonstration garden is a great place to start.

While we worked in the garden, we were visited by Phoebis sennae, Sulphur butterflies. These are the yellow ones quite often seen in our great city. A Papilio cresphontes, Giant Swallowtail, spent about 20 minutes laying eggs on the Wafer ash tree. Other visitors were the Battus polydamas, also called the” Goldrim,” happily feasting upon the Bauhinia mexicana blooms.

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We were visited by quite a few squirrels busily scampering about up and down the tree trunks.  A female red breasted robin was busy teaching her young ones how to retrieve the earth worms erupting from the fresh earth as we turned it over with our shovels. Our time spent in the garden was a nature nurturing delight.

Just beyond the roped fence, sits a paved patio with picnic tables shaded by large cloth umbrellas available for visitors to enjoy their lunch.  Not a day goes by that you don’t see native species of butterflies fluttering about while you munch on your lunch. Next time you are at the museum, take time to view this garden and see what plants you might want to place in your own garden.  Feel free to pick up a free Butterfly Gardening Brochure available on the plant cart outside of the Collector’s gift shop.