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

October 18, 2015

FRANGIPANI HORNWORM
Here at the peak of our rainy season, the Hacienda's Frangipani trees are as leafy and green as they'll get, though bearing hardly any flowers or fruit. Frangipanis are gorgeous, important ornamental trees planted worldwide, yet they're native to the Yucatan and found in our surrounding forests. You may want to review our Frangipani Page at http://www.backyardnature.net/mexnat/frangipa.htm.

During my afternoon garden-walks, when I pass a Frangipani, often it pays to search among the leaves, for lately one of the most boldly patterned and pretty of caterpillar species has been turning up there, the Frangipani Hornworm, PSEUDOSPHINX TETRIO. One about as long as my finger is shown resting on the lower side of a succulent Frangipani stem http://www.backyardnature.net/n/15/151018fh.jpg.

A close-up of the caterpillar's very red head end, featuring an orange "collar" with curious black specks, is shown at http://www.backyardnature.net/n/15/151018fi.jpg.

When an animal with no obvious defenses such as sharp horns or pincers seems to go out of its way to draw attention to itself, a good bet is that either you have a very bad tasting or poisonous species, or one mimicking a bad tasting or poisonous species. Since Frangipanis copiously "bleed" a white, milky sap when injured, and the species is in the Dogbane Family, the Apocynaceae, known to embrace many poisonous plants, from the first I figured that these pretty Frangipani Hornworms must be full of deadly chemicals. When the caterpillars first turned up, my Internet connection was poor so I asked volunteer Bea in Ontario to see if she could find mention of such chemical defenses.

In her usual quick and efficient way, soon she'd emailed a page from the Internet reminding us that such color patterns are found everywhere throughout the insect world, from black and yellow-striped stinging wasps to black and red, bitter-tasting ladybird beetles, and brightly-colored, poisonous tropical butterflies. A fine technical word used to refer to conspicuous colors and patterns serving to warn is "aposematic."

The "Biodiversity in Belize" website describes a Squirrel Cuckoo -- a species fairly common here -- returning to a Frangipani Hornworm infested tree again and again for a meal. The bird would simply whack its caterpillars against a branch until the poisonous gut flew out, then it'd swallow the remains. Interestingly, this caterpillar-banging behavior seems to be genetically programmed in the Cuckoo taxonomical order, for anis (also in the order) also have been observed doing it, and here we have plenty of Groove-billed Anis, too.

The Belize page also describes a heavy infestation of Frangipani Hornworms that completely defoliated the shrubs they were feeding on, and after that began feeding on the main stems. Despite these caterpillars being able to eat up to three large leaves each day, generally even large numbers of caterpillars don't kill the plants, though they certainly can damage them. Frangipani Hornworms are so large and conspicuous that when outbreaks occur the best control for them is to simply look for them and pick them off.

When the Frangipani Hornworm metamorphoses, it produces a drab, brownish-gray sphinx moth as plain looking as the caterpillar is spectacular.

*****

SHRUBBY WOODSORREL
Once or twice a week I hike or bike into Pisté, mostly to buy fruit. Nowadays, at the peak of the rainy season, the weedy roadside is lushly green and woolly, and this week a certain weedy little wildflower was putting on a show with bunches of small, yellow flowers, as shown at http://www.backyardnature.net/n/15/151018ox.jpg.

At first they reminded me of one of those tiny bush marigolds that load themselves with daisy-type flowering heads. However, up close the flowers turned out to be not at all daisy-type, and the leaves were trifoliate, or composed of three leaflets, like clover leaves, seen at http://www.backyardnature.net/n/15/151018oy.jpg

Northern wildflower-lovers know that this combination of small yellow flowers and trifoliate leaves normally indicates a woodsorrel, genus Oxalis. As a child in Kentucky I was taught to call Oxalis species "sourgrasses," though of course they are far from being grasses. It's true, though, that the leaves are so chock-full of oxalic acid that they're very acid to the taste. Often in my salads I've added a few Oxalis leaves just for the taste.

There's something unusual to notice in the above photograph. Notice that the triangular, sharp-pointed sepals below the corollas, and wrapping around unopened flower buds, have violet-purple edges.

The online Flora of Yucatan lists three Oxalis species for the Yucatan Peninsula, and of these only one bears leaflets of the shape shown in the above photo, plus flowers with purple-edged sepals, and that's OXALIS FRUTESCENS, whose only English name I can find is Shrubby Woodsorrel, though the plant doesn't seem so shrubby to me.

Also, all the pictures of Oxalis frutescens flowers I can find on the Internet -- except for the species' photos at the Flora of Yucatan website -- show sepals without the purple margins. Therefore, maybe our Yucatan plants constitute a special regional race or subspecies.

Since Shrubby Woodsorrel thrives in such disrupted habitats as along the road to Pisté, you might expect that the species enjoys a large distribution, and that's the case, occurring in similar spots from the southern US south through most of South America, as well as weedy spots in such places as the Pacific island of New Caladonia.

*****

A WALK AROUND HACIENDA CHICHEN
On the busy highway connecting Mérida with Cancún, just east of the main entrance to Chichén Itzá ruins, you take a little road on the south side and pass through about a kilometer of low forest. At the end of the road -- just before reaching the wall surrounding the ruins -- turn left into Hacienda Chichen. Immediately, tall palms with glossy, viny aroids climbing their trunks create a cool, shadowy, peaceful alley, at the end of which you encounter the Hacienda's main building, the Casco, shown at http://www.backyardnature.net/n/15/151018hc.jpg.

The Casco dates from the 16th century. Climb its steps, turn around and look toward the road you just came down, and you see what's shown at http://www.backyardnature.net/n/15/151018hd.jpg.

From that same vantage point, twist just a little to the right and you see the big Chinese Banyan shown at http://www.backyardnature.net/n/15/151018hf.jpg.

Back in the 60s when I first visited Chichén Itzá ruins as a backpacking student, I recall the land immediately around the ruins as weedy, scrubby ranchland, and old timers today remember when the stone arch behind the banyan was an entrance to a cattle lot.

Inside the main building, once folks at the reception desk have taken care of you, you might want to eat something at a table on the back veranda. From there a nice view opens into lush vegetation, with Melodious Blackbirds and parrots often calling. You can see the view over one of my recent meals at http://www.backyardnature.net/n/15/151018he.jpg.

The guest bungalows are scattered through a park-like garden, a typical view shown at http://www.backyardnature.net/n/15/151018hk.jpg.

A couple minutes of walking takes you to the 16th century church shown at http://www.backyardnature.net/n/15/151018hg.jpg.

The church stands atop a mound surely built by the ancient Maya, and the church itself is constructed of recycled stones from Maya ruins -- standard church-building procedure back in the 16th century. When I first arrived to stay at Hacienda Chichen in 2009, I lived in the Church's yellow-painted attached section on the right. The main church is well maintained and occasionally hosts weddings, both for local folks and visitors. A view of the inside is shown at http://www.backyardnature.net/n/15/151018hh.jpg.

I lived in the church's attached area only a few weeks before the hacienda's owners built a Maya style, thatch-roofed hut in the woods about a minute's walk from the main building, in which I lived until 2012, serving as both "naturalist in residence" and living curiosity/exhibition. Right now for various reasons I'm living in an apartment on the grounds, but in November I'll return to the hut and live as before. You can see the hut as it appears today, with some of the plants I planted years ago flourishing, at http://www.backyardnature.net/n/15/151018hi.jpg.

The main change at the Hacienda since I left in 2012 is that now the garden area is much expanded and more effort is being made to organically grow crops that can be used at the Hacienda. A shot of an area that when I left was nothing but tall, weedy grass and shrubs, is shown at http://www.backyardnature.net/n/15/151018hj.jpg.

The elevated structure at the right in that picture is a kanché, a Maya way of getting important plants away from hungry iguanas, and where leafcutter ants are less likely to invade. The rock-framed gardens at the left are Maya eras, in which healthy crops of chives, or cebollín, are growing. In one such era, I've sown some mustard greens and collards.

Though the seeds I've planted are a year old, carried down from Texas, and were one of those 10¢/pkg deals, I have high hopes for them. Also I'm hoping that friends from up North might bring other seeds of greens, herbs and ornamental flowers.

*****

FEATURED ESSAYS FROM THE PAST:

"Dog with Blue-Gray Eyes" from the February 11, 2006 Newsletter, at http://www.backyardnature.net/n/p/060211.htm

"Oil Spill Philosophy" from the October 26, 2003 Newsletter, at http://www.backyardnature.net/n/p/031026.htm

*****

Best wishes to all Newsletter readers,

Jim

All previous Newsletters are archived at http://www.backyardnature.net/n/.