JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from Hacienda Chichen Resort
adjoining Chichén Itzá Ruins in
Yucatán, MÉXICO

JULY 10, 2016

*****

TOBACCO HORNWORMS
The garden's tobacco plant continues to be a highlight during my daily 4 o'clock walks. Everyone knows about tobacco, many hold strong opinions about it, but very few know what the plant looks like. You can see it flowering prettily back in March at http://www.backyardnature.net/mexnat/tobacco.htm

Nowadays the plant is even more of an attraction because it hosts several Tobacco Hornworms such as the colorful one shown at http://www.backyardnature.net/n/16/160710th.jpg

That one was about two inches long (5cm). A smaller one with its colors less developed appears at http://www.backyardnature.net/n/16/160710ti.jpg

Growing up on a tobacco farm in Kentucky in the pre-chemical days, I got to know this caterpillar very well. We spent a lot of time "worming" our fields, a job I didn't like at all because I felt sorry for the worms. I was supposed to snap their heads off but could only bring myself to toss them on the ground between the rows, in the hope that birds might eat them.

Later in life when I was gardening, Tobacco Hornworms turned up on tomato plants. There's a similar looking hornworm called the Tomato Hornworm, but instead of having those / / / / slash marks along their sides, their markings are lying-down Vs, like >>>>. From what I read, Tomato Hornworms feed on tomatoes in the northern states, but in the southern states Tobacco Hornworms do the job.

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FUZZY APATELODES CATERPILLAR?
With the advent of the rainy season the landscape suddenly is lush and green with newly emerged vegetation, with caterpillars eating that vegetation. The diversity of caterpillars is stunning. But, down here not much is known about many, maybe most, caterpillars, so it's hard to impossible to identify them just by matching what you see with identified caterpillar pictures on the Internet. I knew that when I took the following picture of one feeding beneath a Bauhinia leaf, but took the picture anyway, thinking that its novel features of fuzz might help in the ID process. The image is at http://www.backyardnature.net/n/16/160710fx.jpg

Another view better showing the fuzz tuft arrangement is at http://www.backyardnature.net/n/16/160710fz.jpg

A surprisingly dark-orangish head is shown at http://www.backyardnature.net/n/16/160710fy.jpg

Up north tussock moths produce similarly distributed fuzz tufts, so when volunteer identifier Bea in Ontario saw the pictures she immediately started with that group, but found nothing to her liking. Eventually she wrote back, appending a picture of a caterpillar up north not occurring here, pointing out that "It has all the tufts in the same place, a red head, the only difference is color and length of hair." That northern caterpillar was identified as Apatelodes auduboni, so a good guess is that our fuzzy-yellow caterpillar is a member of the genus Apatelodes, of which several are listed for this area, but not illustrated; or at least they might belong to the same family, the Bombycidae.

I find hardly any lifecycle information about Apatelodes species. Here we'll just park our pictures under the keyword Apatelodes, and maybe someday an expert working on the genus will find the page and be glad to know that in early July the caterpillar in our picture turned up near Chichén Itzá ruins in the central Yucatán, México, feeding lustily on a leaf of Bauhinia ungulata, the "Cowfoot," a member of the Bean Family.

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MATING VARIEGATED FRITILLARY BUTTERFLIES
I'm tickled with the picture of mating variegated fritillary butterflies shown at http://www.backyardnature.net/n/16/160710xx.jpg

Not only does it show how they do it, and that the two butterflies are somewhat differently colored, but also they're hanging onto a pale, discarded casing of a chrysalis, a chrysalis being the resting or pupal stage in butterfly metamorphosis occurring between the caterpillar and the winged adult stages.

It's hard to resist believing that the female had just emerged from her chrysalis, ripely emitting powerful sexual pheromones, and a male came along and got her maybe even before her wings were dry.

She must have been redolent of pheromones, for as I took the picture another male, sometimes two males, and once even a male of a different species -- some kind of yellow sulfur butterfly -- flitted around the pair, evidently wanting some of the action. You can see one of the invaders in midair at http://www.backyardnature.net/n/16/160710xy.jpg

My presence unnerved the male a couple of times, so that he tried to fly away, but the female refused to move and anchored him there as he beat his wings. Later while watching Variegated Fritillaries feeding at the cosmoses next to my hut, a mating pair landed, with one doing all the flying and the other just riding along, being pulled through the air backwards. My impression is that when fritillaries mate it's a slow process and one that doesn't end until it's all done.

The number of Variegated Fritillaries on the landscape now is amazing. Not far from where the above pictures were taken, a bathtub-size bunch of white-flowering Scorpion Tails, or heliotropes, was much occupied with them. A small part of the plant with some visitors is shown at http://www.backyardnature.net/n/16/160710xz.jpg

*****

TREE CYCAD PRODUCING A CONE
When I first arrived at Hacienda Chichen in 2009 maybe the most impressive plant found here was the tree cycad shown at http://www.backyardnature.net/yucatan/dioon.htm

Nowadays usually I begin my 4 o'clock walks on the main building's veranda and our first stop is there right beside us, where the tree cycad stands. Partly to figure out the guests' level of Nature-savvy so I can customize the rest of the walk for them, I ask if they can figure out what KIND of plant the cycad is, and of course most guess that it's a kind of palm. Then I point to the huge cone the tree, one exactly like what's shown in the 2009 picture.

Once it's clear that the pineapple-like thing on the tree is a cone, some people realize that they're dealing with a coniferous plant, and at that point many understand what a special thing a cycad is. Coniferous plants most visitors are familiar with are evergreen trees like pines, spruce and firs.

Then I explain that cycads are very primitive conifers, or gymnosperms, so primitive that along with spore-producing plants such as treeferns and giant horsetails they contributed a major part of the Earth's "forests," or what was the beginning of forests, back in the Jurassic Period ±145-200 million years ago. At that time, Eurasia and the Americas were joined into the supercontinent called Pangea, and dinosaurs reigned on dry land. The first flowering plants appeared about 150 million years ago, but it took millions of years before they began pushing the cycads and other gymnosperms aside.

So, with all that in my mind, I was happy when one of the Hacienda's younger tree cycads turned up with an immature, American-football-sized and -shaped cone pushing up between the bases of its crown leaves, shown at http://www.backyardnature.net/n/16/160710cy.jpg

A close-up showing the white-hairy future cone scales packed tightly next to one another is at http://www.backyardnature.net/n/16/160710cz.jpg

Cycads come in either male or female plants, and at least during their early stages of development the cones are fairly similar. I think that the cone in our picture is a female, but I find pictures on the Internet with cones looking just like this labeled as male. I'm just going to wait and see which sex this cone turns out to be. If it happens to be male, that'll be great news because it opens the possibility of pollinating the big female featured on our Tree Cycad page. That big female does produce seeds, but the seeds are empty and sterile, as shown toward the bottom of our page.

By the way, in 2010 when I wrote about the big female on our Tree Cycad page, I mentioned that the fleshy tissue around the seeds was succulent and not bad tasting. Since then I've read that at least the tree's foliage and seeds contain toxins. However, I also read in the "Flora de Veracruz" that natives in the tiny area of Veracruz State where this species grows naturally eat the seeds in tamales. Also, the species has suffered from their leaves being gathered for religious celebrations. The Flora says that, as ornamental plants, in 1967 the trees were sold in lots of up to 30,000 individuals, for a price of 6 pesos for each plant.

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THE SPURGECREEPER'S STRANGE FLOWERS
Twining up through a thicket of dead, weather-bleached stem-remains of last season's beautiful roadside Sunflower Goldeneyes, along a narrow, gravel road to a local garbage dump, a homely little vine with leaves caught my eye, simply because it was something green amid a lot of grayness. You can see the situation at http://www.backyardnature.net/n/16/160710dc.jpg

One of its deeply three-lobed leaves is shown at http://www.backyardnature.net/n/16/160710dd.jpg

Its flower cluster was very unusual, with flowers mostly hidden inside two deeply lobed, leafy bracts a little paler green than the leaves, as shown at http://www.backyardnature.net/n/16/160710de.jpg

While taking these pictures I was thinking that something I'd not seen in the Cucumber/Melon Family had turned up, though I couldn't recall any species in that family producing such bracts. Since I don't see so well, it wasn't until I got home and put the following picture on the computer screen that it became apparent that not only was this in some other family, but that the flowering structures were outright bizarre. You can see what I mean at http://www.backyardnature.net/n/16/160710df.jpg

In this picture, notice the vertical, green, slender item atop the uppermost roundish thing. The slender thing is a style topped by an expanded stigma, so the roundish thing beneath it is an ovary. Notice that the ovary appears to be somewhat 3-lobed. The picture shows at least three ovaries, all subtended by slender calyx lobes equipped with stiff, white bristles. There's no hint of male flower structures in the picture. When you see a 3-lobed ovary with the style emerging where the lobes join, and the flowers are unisexual, you should automatically think of the big, widely occurring Spurge or Euphorbia Family.

In the world of flowers, certain species can bear several separate ovaries in a single flower, as appears to be the case here, but in those blossoms each ovary is not subtended by its own calyx or bracts, which each of these ovaries clearly is. I can't recall having ever seen anything like this. However, I did remember seeing pictures of a vining member of the Euphorbia Family enveloping its flowers with large bracts like this, so now that species finally had turned up.

It's DALECHAMPIA SCANDENS, sometimes in English known as Spurgecreeper, distributed from the the southern US where it's sometimes weedy, southward through all the America tropics, plus, apparently, and surprisingly, also there are native populations in Africa.

There's plenty of scientific literature about the genus Dalechampia and its 100 or so species of twining vines, precisely because its flowering structure is so weird. Evolutionary biologists like to explain how things evolved to be the way they are, and this vine's "bibracteate inflorescences" have been hard to explain. It's more or less understood now to be a "terminal staminate pleiochasim juxtaposed to a 3-flowered pistillate cyme," as Grady and Barbara Webster at the University of California, Davis, describe it, but once such a kinky arrangement is recognized the question becomes, "What forces of evolution could account for such a curious thing?"

The ongoing attempt to explain it all has come up with some unexpected insights that, of course, just lead to more questions. For example, our local Spurgecreeper species has been shown to comprise two or maybe three or even more "cryptic species" -- cryptic species being populations in which it looks like all the individuals are of the same species, but then it's found that certain groups within the species don't interbreed with one or more other groups -- another. And, by definition, populations that don't interbreed with one another are considered different species. They're "hidden species," cryptic.

With our local Spurgecreeper species the mystery is even greater because sometimes the different cryptic species live in the same place, and even share the same pollinators, which are bees. How do the genetically isolated populations stay genetically isolated? Researchers in the field try to figure it out.

A further curiosity is that though each cluster of flowers on each Spurgecreeper vine bear both unisexual male and female flowers, and regular pollination definitely takes place, sometimes Spurgecreeper closes its bracts over its flowers, keeping out pollinators, and pollinates itself -- a process that seems to kick sand in the face of sexuality itself. Why have sex, Surgecreepers seem to be asking, when you can impregnate yourself exactly when you're ready?

Who would have thought that such an humble little vine might live such an iconoclastic existence? I'll be keeping my eye on this vine, hoping to find some male flowers, and maybe see other features of its strangeness.

*****

WILD MELON
During a bike trip down the highway between Chichén Itzá and the little town of Xcalacoop just to the east, a sprawling vine about 15ft long (4.5m) was spotted running along the base of a limestone roadcut, shown at http://www.backyardnature.net/n/16/160710cu.jpg

Lots of vines trail alongside the road, even over that bare, sun-glaring limestone, but do you see the spherical fruit at the far left of the vine? A closer look is at http://www.backyardnature.net/n/16/160710cv.jpg

It looks like an immature cantaloupe, or musk melon, and those leaves, yellow male flowers, and unbranched tendrils all agree with that assessment. A close-up of a unisexual male flower is shown at http://www.backyardnature.net/n/16/160710cw.jpg

It's all just like a cantaloupe vine but, do cantaloupes "go wild" to the extent that they can flourish in such a seemingly inhospitable spot as this?

After "doing the botany," I found that it was indeed a cantaloupe, the field mark not least important being that the fruit was spherical with a hairy but not spiny covering, and even in its immature state, so large. So, yes, it's CUCUMIS MELO, the melon, of which any number of tasty and variously looking cultivars have been developed.

Also I read that melon vines do indeed sometimes "go wild," especially in tropical and semi-tropical environments, and even in the Americas, though the original stock seems to have been from Asia. Still, finding this melon thriving in such a seemingly hostile environment, I can't avoid remembering certain of my garden cantaloupes who just withered and died, no matter how I pampered them.

*****

"DO NOT SOW OR REAP... "
Sitting beside the hut door reading, needing to rest my eyes, I looked up and saw a golden cosmos blossom glowing radiantly against the bright blue sky. At the same time a Gulf Coast Fritillary butterfly, also golden but with well-formed white streaks daintily outlined in black, suddenly glided onto the blossom and instantly, with quivering wings opening and closing, began probing the flowers with its slender, fragile proboscis, one tiny disk flower after the other. I stood up and took a picture of all this with the hut's roof in the background, as you can see at http://www.backyardnature.net/n/16/160710gc.jpg

Our human brains are wired so that certain combinations of stimuli habitually evoke specific memories or associations. It's exactly like Pavlov's dogs salivating when the bell rang, except that our responses tend to be a little more complex, but who knows? When I saw the orange blossom and butterfly so vividly alive and seemingly anxious to get their work done, the association that for less than half a second flashed through my mind -- and always flashes when I see things like that -- was a passage in the Bible, Mathew 6:26:

"Look at the birds of the air; they do not sow or reap or store away in barns, and yet your heavenly Father feeds them."

During my younger days when I was trying to come to terms with my spiritual needs, the moment I read that, I saw the true nature of sacred scripture. From that moment I felt free to move on in my spiritual development, for, even at that age, I was quite sure that if people didn't do some kind of sowing and reaping they'd get in a mess, and even birds of the air, butterflies and all other living things had to work hard for their food, and some birds even stored their winter supply in something like bird barns.

My later spiritual quest took many turns, even into atheism, but in the end a certain revelation slowly germinated inside, grew and blossomed, setting me on what seems now to have been the right path. Over time I came to recognize that Nature is so exquisitely complex, diverse, and beautiful, that at the very least there must be some kind of creative impulse that caused the Universe to exist in the first place, to function as it does, and to keep it evolving toward ever higher states.

No second revelation of this profound, life-changing character, however, has come to me. My decades of growing old have been occupied with daily confirming for myself the features of that first and only self-blossomed insight -- that there must be some kind of Universal Creative Impulse to account for all this glorious Creation, and that somehow to think about it all, and to reflect on my place in it, fulfills me in a certain way.

The Universal Creative Impulse is a poet, and all Nature -- and we humans are part of Nature -- is Her poem; we things are music the Creator expresses in terms of atoms and molecules, electromagnetism, energy and lots of other stuff interacting with one another in evolving, ever-more-sophisticated, ever-more-promising patterns.

So when I look up from reading, and see the beauty of the golden fritillary working so hard for nectar in flowers the plant has worked hard all season to bring to this exact moment of perfection, for half a second my childhood cultural programming summons that passage in Mathew, but then comes a much longer, happy time of simply watching the butterfly and plant being themselves.

*****

Best wishes to all Newsletter readers,

Jim

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