November 28, 2010
PUPA ON A ROCK
Two weeks ago Santos came to my door and said, "There's something on this rock you might like to see." He'd been gathering limestone rocks to build a traditional elevated clothes-washing sink, or batea, behind my hut. You can see Santos's inch-long (25mm) item stuck to the backside of the basketball-size rock at http://www.backyardnature.net/n/10/101128pp.jpg.
It's the pupa, or resting stage, of a lepidopterous insect -- the third step in the four-step complete metamorphosis of a butterfly or moth. Remember:
egg --> larva --> pupa --> adult
In the above picture, on the pupa's right side you can see the pattern of wings developing just below the pupa's husk. On the right side there are low, rounded ridges indicating the future adult's segmented abdomen. At the pupa's bottom, notice the diagonal, zipper-like design.
I shipped the picture to Bea in Ontario, suggesting that the zipper design was an artifact of the feathery antenna of the adult developing inside. Since butterflies have simple, hairlike antennae and moths have feathery ones, I guessed that a moth was developing inside. She wrote back:
"Most moths spin a cocoon or go underground to pupate and their pupae are usually just plain rusty brown with no markings."
So, she thought that this was a butterfly pupa, in which case the special name for the pupa would be "chrysalis." We'd say that we had a chrysalis stuck to a rock. Bea wondered if the zipper-like marking might not represent the fracture line along which the pupal husk eventually would split, and where the adult would emerge. Maybe the zippery line really was like a zipper.
All we could do was wait. I placed the rock next to my door and resolved to look at it each time I passed. About a week later, this Tuesday, I found what's shown at http://www.backyardnature.net/n/10/101128pq.jpg.
The adult had emerged and left, and it looks like Bea was right about its being a butterfly chrysalis, with the husk fracturing along the zippery lines, as shown at http://www.backyardnature.net/n/10/101128pt.jpg.
I was disappointed that the adult had gotten away, until I saw exactly what you can see at http://www.backyardnature.net/n/10/101128ps.jpg.
The split chrysalis lies at the lower left while the adult rests at the top, right, drying and stiffening its wings. The beautiful wing patterns are shown close up at http://www.backyardnature.net/n/10/101128pr.jpg.
When I got too close to the adult the wings briefly spread, enabling me to glimpse the wings' upper pattern and colors, and know what species we had: The Blomfild's Beauty. It was a female of this sexually dimorphic species. We've already looked at Blomfild's Beauties. You can our earlier account for that species at http://www.backyardnature.net/yucatan/blomfild.htm.
SEXUALLY DIMORPHIC BUTTERFLIES
Blomfild's Beauty wasn't the only sexually dimorphic butterfly species met with this week. I sent Bea what I thought was a new species of yellow butterfly, but she figured out that it was just the female of a species whose male already is represented on our famous Yucatan Butterfly Identification Page at http://www.backyardnature.net/yucatan/mariposa/.
We're talking about the Dina Yellow, PYRISITIA DINA.
You can compare the sexes -- the male on the left -- at http://www.backyardnature.net/n/10/101128xx.jpg.
Notice that although the male and female color patterns are strikingly different, the vein pattern is identical in both sexes. In insect identification it's nearly always the case that wing venation is much more important than color.
RAINBOW AMEIVA LIZARD
Though I've been at the Hacienda for over a year, somehow new things just keep popping up. That was the case this week when I retrieved a wheelbarrow leaning against the tool shed's wall and met the critter shown at http://www.backyardnature.net/n/10/101128am.jpg.
Notice how the head scales are large and shiny but immediately behind those big scales are unusually tiny ones. In reptile identification, coloring and patterning is much less important than scale configuration, and this little critter had a scale pattern unlike any other I'd seen here.
With Jonathan Campbell's Amphibians and Reptiles of Northern Guatemala, the Yucatán, and Belize it was easy to figure out that this was a female or maybe juvenile Rainbow Ameiva, AMEIVA UNDULATA, a member of the Ameiva and Whiptail Family, the Teiidae. Field marks for that family include the long, pointed snout, the head distinct from the neck, and those large, flat, platelike scales on the head contrasting with the tiny, granular scales behind.
The male looks very different. Several times I've seen one cross the open space before the hut, but he always disappeared before my I could get my camera out. Males are much larger than females, reaching about 20 inches (50 cm) long, and the sides of their brown bodies are prettily adorned with irregular, alternating, vertical, chestnut and turquoise bars. The breeding male's throat, or "gular area," is brightly red- orange.
Campbell reports that the species occurs in a wide variety of habitats but is most common at forest edges or clearings. Mostly it eats insects, and several common snake species eat it.
Rainbow Ameivas, also sometimes called Metallic Ameivas, are distributed from Mexico to Costa Rica.
A PREENING MALE CANIVET'S EMERALD
Last May we met the Canivet's Emerald hummingbird, CHLOROSTILBON CANIVETII. A pretty picture showing a drab female hovering beside a Royal Poinciana flower is at http://www.backyardnature.net/n/10/100523hu.jpg.
Now I have a picture of a glittery, emerald-green male scratching himself and preening in morning sun at http://www.backyardnature.net/n/10/101128hu.jpg.
The image on the left shows how thick-based the bill is, like the similar-looking Broad-billed Hummingbird, which shouldn't occur here. The picture at the right shows the deeply forked tail twisted sideways. The Canivet's used to be called the Fork-tailed Emerald.
Howell reports that members of the Canivet's genus, Chlorostilbon, bear beaks 1-1¼ times that of the head. Broad-billed beaks are 1¼ to 1-1/3 times the thickness. The bill in the image at the left is about the same length as the head, which fits Chlorostilbon, the Canivet's.
This may sound like lots of nitpicking, but when you have several look-alike species, identification often rests on such details. Without seeing the deeply forked tail at the lower right, even with the other clues, I wouldn't have been 100% sure of the ID.
With the dry season's arrival, I've put in front of the hut a black plastic trough about three by two feet along its sides and half a foot deep, placed a big limestone rock in its center, and filled the trough with water. The very first and most frequently returning critter to visit was the dragonfly shown at http://www.backyardnature.net/n/10/101128df.jpg.
In that picture notice the black trough right below. In dry-season Yucatan where the only standing water is in sinkhole, or cenote, bottoms, this dragonfly is very attached to the little pond!
Bea and I together pegged this as the Carmine Skimmer, ORTHEMIS DISCOLOR, a very widely distributed species occurring from Texas and the Caribbean all the way south to Uruguay in South America. Apparently in the US there's a similar species, the Roseate Skimmer, Orthemis ferruginea, from which we distinguished it by minor differences in the wing venation. In dragonfly identification, wing venation is the thing.
SQUASH FLOWERS & FRUITS
Plenty of celebrating goes on at this time of year down here, but last Thursday was regarded as just another day. However, I remembered past Thanksgivings up North, so Thursday afternoon in the organic garden I found a squash, boiled it in a pot over my hut campfire, and that was my Thanksgiving supper.
Actually, I'm not sure what you'd call the item I ate. It's a traditional Maya crop, not really like what most English speakers think of as a squash, pumpkin or gourd. It was a cultivar of CUCURBITA PEPO, a native American species from which a rainbow of field pumpkins, yellow-flowered gourds and summer and bush squashes have been horticulturally derived.
You can see a leaf and flower of the thing I ate at http://www.backyardnature.net/n/10/101128sq.jpg.
Flowers in the Squash Family, the Cucurbitaceae, are unisexual. Since the flower in the above picture has a small fruit at its base, it's a female flower. A closer look inside that female flower is at http://www.backyardnature.net/n/10/101128sr.jpg.
The hairiness of the yellow corolla walls provides a foothold for pollinators entering the flower. The immature fruit beneath the corolla is a developing "inferior ovary," which means that the corolla arises above the ovary, not at its base, as with "superior ovaries." The ovary's slender neck, or style, has three branches, and at the tip of each style branch there's a two-lobed stigma. The stigma is where pollen from male flowers germinates. In the above picture, notice what appears to be a cup at the corolla's bottom. A pollinator busy inside the cup is gathering nectar. One side of the corolla has been removed so you can see both the cup and the developing fruit at http://www.backyardnature.net/n/10/101128ss.jpg.
The cantaloupe-size meal on my table is shown at http://www.backyardnature.net/n/10/101128st.jpg.
You may recognize this squash as an "heirloom" variety sometimes known as the Globe Squash, Round Zucchini or Ronde de Nice. I'm not sure if it's the same thing. It may be the Maya ancestor of those cultivars.
I do know that the white seeds were as tasty as the flesh and that the flesh, when teased, became stringy. I've heard of "spaghetti squash," so maybe that's close to this. It tasted good, though not as sweet as field pumpkin or as flavorful as summer squash -- more like zucchini. The rind was like thin, brittle plastic, not as soft as regular Zucchini's.
WITCHES'-BROOM ON PHILODENDRON
Witches--brooms are those spiky clusters of stunted, deformed twigs you sometimes see on trees up North, especially oaks, hackberries, Honey Locust and junipers. Since they damage the plants they grow on they're considered diseases, and they can last for many years. Witches'-brooms are caused by many kinds of organisms, including fungi, insects, mistletoe, dwarf mistletoes, mites, nematodes, phytoplasmas and viruses. Some people confuse witches'-brooms with bird or squirrel nests.
The most commonly seen witches'-brooms around here grow on Philodendron vines. One is shown at http://www.backyardnature.net/n/10/101128wb.jpg.
That bushel-basked-size mass of slender, semisucculent stems is very different from the large, glossy leaves and thick, flexible stems of the parent vine, shown at http://www.backyardnature.net/yucatan/philoden.htm.
When I looked closely at the witches'-broom's shoot tips I saw features looking like tiny, aborted flowers, and tiny fruits like the slender capsules of some plants belonging to the Mustard Family. You can see such "aborted flowers" and "fruits" at http://www.backyardnature.net/n/10/101128wc.jpg.
However, the hand lens showed that the "flowers" were just stubby, deformed stem segments with stipules clustered at their tips like petals. With a razor I cut across one of the fruitlike items and saw what's shown held between my fingertips at http://www.backyardnature.net/n/10/101128wd.jpg.
I'm interpreting the black mass in the middle of the thickened stem tip as maturing fungal spores, not ovules developing into seeds, which I'd halfway expected.
My guess, then, is that our Philodendron witches'- broom is caused by a fungus. Here at the beginning of the dry season the green stems forming the broom are dying and turning brown. The resulting dead, brown parts become crumbly and gradually degenerate as wind animates the mass. In such a haphazard but apparently effective way, spores are released into the wind, which carries the spores to new hosts.
Often I've mentioned the Mayas' high degree of social sophistication and their steadfast group solidarity. This week when a friend requested that on my trip into Pisté to buy bananas I also buy him a certain snack, I learned something new.
For, my friend wanted a package of Sabritas, which is junk food as bad as the worst the US has to offer -- oversalted, too-greasy, preservative-rich starchy items sold in small, plastic packages. I tried to convince my friend that such snacks are bad for his health but, no, he had a special craving, a craving it was important to satisfy, and his craving was for a package of Sabritas. For, his wife was pregnant...
You guessed it: In the Maya culture, to a certain extent the male shares pregnancy with his mate. The male can crave foods, suffer morning sickness, and some males even experience some pain of labor.
NO MULCH FOR THE MAYA
In various pictures I've shown you of our organic garden area you may have wondered about the complete barrenness of the soil between plants and beds. Usually in organic gardens you see lots of mulch.
This week I was suggesting how useful placing mulch around plants might be now that the dry season has come. However, before I could explain how mulch helps soil retain moisture and how it enriches the soil with organic matter and nutrients as it decays, the Maya man listening took his machete, flipped up some leaves on the ground, revealed a big, hairy spider, and said:
"Look, that's the kind of thing that plant-trash on the ground attracts. That bicho eats plants. Why attract things that'll eat up your garden?"
I was stunned that a man who all his life has supported his family by cultivating a large milpa, or traditional cornfield, would assert that spiders eat garden plants. Neither would he buy my claim that invertebrates who eat garden plants are not the same species found under leaves on the ground. What I said about soil organic matter and nutrient release simply didn't seem to register.
Later I asked another Maya farmer if he could think of a single instance when the Maya use organic matter to enrich or improve the soil.
"No," he said.
I asked his thoughts about spreading mulch beneath the Hacienda's ornamentals. Though this man knew volumes about local medicinal plants, he now expressed exactly the opposite of what I was taught in Soils Class back at the University of Kentucky. "When dry weather comes, mulch sponges up moisture from the soil, and of course that hurts the plants," he said.
Over the years I've seen many references to sustainable farming techniques of indigenous Americans before the arrival of Europeans. Mainly they were talking about "slash and burn." Cut down a patch of forest, burn it, that releases a flush of nutrients in the ash, resulting in bounteous harvests for two or three years. But then weeds and animal pests invade, the soil grows depleted of nutrients, soil structure deteriorates from erosion and loss of organic matter, and after a few years the plot must be abandoned, the farmers go elsewhere, and start the cycle all over. Once the slash-and-burned plot reverts to forest, it may be slashed and burned again.
Well, this technique is sustainable only in areas of low human population density. When population increases, there's not enough forest to go around, and periods between slashings and burnings shorten until the land no longer has enough time to recuperate. Soil is eroded away or gradually converted to relatively sterile, hard-packed dirt.
More and more I'm thinking that Classic Maya civilization may have collapsed not only because of stresses brought on by overpopulation but also because of destructive, unsustainable farming practices. The Maya never discovered the wheel, except for its use on small toys, and from what I see here they never realized that conserving soil organic matter is supremely important for long-term soil fertility, and that mulch helps soil retain its water during dry spells.
Historically, I suspect that not appreciating soil organic matter and the use of mulch has been a greater misfortune for the Maya than having missed out on the services of the wheel.
DIFFERENT WAYS TO BE THANKFUL
If the Maya never learned about the importance of soil organic matter or the usefulness of mulch, it's also true that they never forgot how to express their gratitude for the bounty that Nature supplies them.
I am astonished how even today Maya farmers in their baseball caps and shirts printed with slogans such as "Born to Boogie" remember the dates for offering prayers of thanks and sacrifices, and faithfully fulfill their obligations. Often on special occasions I've seen José the shaman in his white suit with great dignity pour sacrificial pozole (cornmeal/water emulsion) and balché (tea from sacred Balché tree bark) to the East, West, North and South.
The Maya ceremony is simple and personal. In a sense, what's being said is "You, Nature, give us corn, so here with this pozole I return to you the very best of what you gave to me. You, Nature, bring forth the forest in which the sacred Balché tree grows, so here I give you our balché drink, which both slackens your thirst and returns the Balché essence to its source.
In our culture we seem to assume that paying money for food is thanks enough for everyone and everything involved in getting the food to us. I suspect that that kind of thinking is likely to contribute to our feeling estranged and even abandoned by the Mother Source, even though it's we who mentally and emotionally have done the abandoning.
Best wishes to all Newsletter readers,