Jim Conrad's Naturalist Newsletter

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

November 1, 2015

JAMAICAN FIELD CRICKET
Earlier I told you about sowing seeds of mustard greens and collards in the garden here at Hacienda Chichen. Because the soil was so granular that it dried out easily between morning waterings, I spread cardboard over the beds to keep the soil moist, so the germinating seeds wouldn't dry up and die. When it was time for seedlings to start appearing, each morning I'd peep beneath a few sheets of cardboard, but no seedling ever turned up, not a single one.

However, one morning beneath a sheet of cardboard I did find the handsome cricket shown at https://www.backyardnature.net/n/15/151101cr.jpg.

Normally crickets jump away before close-ups can be taken, but this one seemed to be stunned, at least for a few seconds -- long enough to get the close-up of the interesting broad-based spines on the rear of his tibia, shown at the far left in the picture at https://www.backyardnature.net/n/15/151101cs.jpg.

A split second before he finally jumped, I snapped the interesting head and pronotum markings shown at https://www.backyardnature.net/n/15/151101ct.jpg

To me this looked just like field crickets commonly seen in most of the US, though up there I'd never noticed the upside-down-teardrop design on a pronotum (the "saddle" behind the head) or the white pit above the antenna bases. However, these turned out to be features of eastern North America's common field crickets.

Here are some basic facts about field-cricket taxonomy:

The genus Gryllus (field crickets) is the most-studied of North American singing insects.
For many years, all eastern North American Gryllus species were thought to be a single variable species, Gryllus assimilis. But then it was noticed that similar looking geographical populations sang differently. Once individuals with different songs were closely compared, extremely obscure physical differences were observable, plus there were behavioral differences and differing mating seasons.
Despite all of eastern North America's several native species of field crickets having once been called Gryllus assimilis, now none is recognized as that species. The first, or "type," Gryllus assimilis was described in 1775, and had been collected in Jamaica, so now the species usually is known in English as the Jamaican Field Cricket.
The real Gryllus assimilis is now considered to be native to the Caribbean area and Mexico south to Brazil, plus it appears to have been introduced into southernmost peninsular Florida and a tiny area of southernmost Texas.
The real Gryllus assimilis looks just like ours in the pictures, especially with that saddle-like pronotum covered with dense, brownish hairs -- visible in the last picture -- making it look "fuzzier" than other species.

Taking all this in account, it's clear that GRYLLUS ASSIMILIS is the best bet for the name of a field cricket found in the Yucatan and looking like ours, keeping in mind that field cricket taxonomy, especially in this part of the world, still isn't all worked out.

Jamaican Field Crickets are characteristic of tropical American lawns, weedy fields, roadsides and other open areas. In general, they're described as omnivorous, eating dried organic matter, fresh plant matter, small fruits, seeds, and, when especially hungry, both living and dead insects.

You can hear this cricket''s song in a WAV file from the University of Florida.

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RED-SPOT WASP MIMIC MOTH
A winged critter flitted across the forest trail about a foot off the ground, taking refuge at the trail's edge on the undersurface of a leaf about ankle high. Lying on my back peeping beneath the leaf, I could see that this was something new. You can see it with sunlight brilliantly illuminating its leaf from the top side at https://www.backyardnature.net/n/15/151101mh.jpg.

With such transparent windows in the wings, at first I thought it was a kind of picturewing fly, but flies aren't supposed to have such long, slender antennae, especially not antennae with comb-tooth-like appendages along their lengths, as this insect has. This must be a moth masquerading as a fly or fly-like dipterid. Off the picture went to volunteer moth specialist Bea in Ontario.

It didn't take Bea long to figure out that we did indeed have a moth, a member of the tiger moth genus Cosmosoma. Moreover, she said it looked a lot like COSMOSOMA TEUTHRAS, distributed from central Mexico south through Central America to Brazil. A page on moths of the Andes provides an English name of Red-spot Wasp Mimic, and its true that the moth's particular reddish-orange color is similar to that of certain wasp species, which also bear mostly transparent wings, so we'll go with that name.

Happily, on the Internet, Mexico's University of Veracruz freely offers a download of a paper, a monograph, by Vianney Rodríguez Hernández dealing with the Mexican distribution of a certain subgroup of moths, to which our Red-spot Wasp Mimic belongs. That treatment suggests that in the Yucatan we can look for three species of the genus Cosmosoma, and of those three the most common and the one looking most like ours is Cosmosoma teuthras. The moth paper can be downloaded in PDF format here.

Little is published about Cosmosoma teuthras, though I read that the caterpillars of another Cosmosoma species feed on certain vining members of the Dog Bane Family. That family is famed for producing white latex filled with powerful and often toxic chemicals, often resulting in the caterpillars who eat them being protected from predators not eager to ingest the caterpillars' toxic chemicals. Monarch Butterfly caterpillars feed on milkweeds, which are members of the Dog Bane Family.

During feeding, the collection of chemicals for non-nutritive purposes is termed pharmacophagy, and Cosmosoma species appear to be pharmacologic. It's unclear whether the toxins' protective effects extends to adults of the species. Adults can be found foraging among various types of blossoms.

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NOHOCH CUM/ MAYA RIBBED SQUASH
In the Cucumber Family, pumpkins, gourds, squash, melons and cucumbers aren't always clearly identifiable as belonging to one or the other of those groupings. You might remember our "Maya Cucumbers" that turned out to be cucumber-like melons, the story told at https://www.backyardnature.net/yucatan/pepino.htm.

In the Hacienda's garden, nowadays ground-running vines are producing a big crop of tough-skinned, conspicuously ridged, pumpkin/squash-like fruits, shown at https://www.backyardnature.net/n/15/151101cv.jpg.

Notice that these vines' leaves are roundish in shape and not deeply lobed, setting them apart from many other Cucumber Family vine types. Also, the fruits are fairly large, as shown with my hand for scale at https://www.backyardnature.net/n/15/151101cu.jpg.

The fruits lobes provide most of the edible "flesh," as is apparent on a fruit partly eaten by, probably, an Agouti, at https://www.backyardnature.net/n/15/151101cw.jpg.

That picture also shows that before these fruits mature they are dark green.

Cucumbers and melons belong to the genus Cucumis, whose flowers consist of five distinct petals or nearly separate corolla lobes. Pumpkins, gourds and squash are in the genus Cucurbita, which produces bell-shaped corollas with only shallowly defined corolla lobes. Our vines produce bell-shaped corollas so we can confidently say that our vines' fruits are of the pumpkin/gourd/squash type, in the genus Cucurbita. Our vine's typically Cucurbita, shallowly lobed corolla is shown at https://www.backyardnature.net/n/15/151101cz.jpg.

So, what kind of pumpkin/gourd/squash of the genus Cucurbita is this?

Within the genus Cucurbita, all our multivarious garden pumpkins, gourds and squash are derived from about five domesticated species, which occasionally cross pollinate, confusing the picture. In figuring out which species of Cucurbita our Hacienda vines belong to, the following features were noted:

Unlike vines of the North's common field pumpkin, Zuccini and summer crooknecks -- all Cucurbita pepo -- our vines lack harsh, stiff hairs, plus Cucurbita pepo leaves normally are deeply lobed, unlike ours. You can see the short, relatively soft covering of hairs on one of our vine's leaf petioles at https://www.backyardnature.net/n/15/151101cx.jpg
Unlike seeds of Cushaw and Winter Crookneck Squashes, including Sweet Potato Pumpkins -- all Cucurbita moschata, whose seed margins are very thin and ragged-looking -- our seeds' edges are thickened and rim-like, as shown at https://www.backyardnature.net/n/15/151101cy.jpg.

These features direct us to CUCURBITA MAXIMA, home to many varieties of what Northerners call Autumn and Winter Squashes, such as the Hubbard, buttercup, Boston Marrow and Amish Pie Pumpkin squashes. In other words, despite our fruits being the size and hardness of a pumpkin, they're better thought of as squashes.

Cucurbita maxima is regarded as one of the most diverse domesticated Cucurbita species. Over 4000 years ago it was brought into cultivation in South America, probably being derived from the wild Cucurbita andreana. It's known that domesticated Cucurbita maxima was introduced into North America as early as the early 1500s, while archaeological evidence shows that squashes were cultivated in Mexico before the Spanish Conquest.

On the Internet, since I can't find illustrations of Cucurbita maxima squash exactly like ours, I'm guessing that once again here we have a unique variety produced by the Maya through centuries of selective breeding. Our hot, dry environment certainly is different from that of the Andes, so we have to admire the fruit of the work of our indigenous plant breeders.

The name "Maya Ribbed Squash" is one I made up because our squash doesn't seem to have an English name. The local Maya call it Nohoch Cum -- Cum meaning squash, and Nohoch "very big" -- and they tell me the way you prepare it is in a "pib," a hole in the ground with rocks heated to a high temperature by burning wood around them. Put Nohoch Cum into the pit with hot stones, usually when something like a pig is the main item being cooked, cover the pib, and let everything slow-cook until well done.

Then Nohoch Cum is sweet like sweet potato. Once it's cooked soft, add sugar until you have something like candied yam. Around here it's the common squash grown in traditional cornfields, or milpas.

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RICCIA LIVERWORT
As the rainy season slowly draws to a close, vegetation is luxuriantly green, the air humid and the ground moist to soggy. Trails through the forest are shadowy and somber. On naked dirt on one of those trails near the Hacienda, a kind of plant turned up that often is spotted up north, but in this area with its long, severe dry seasons, seldom is encountered. You can see three patches of them, which are up to about 4cm broad (1½ inch), and with their ribbon-like bodies growing outward from each colony's center, at https://www.backyardnature.net/n/15/151101li.jpg.

These are liverworts -- bryophytes like mosses. Their bodies lack a vascular system, so there's no xylem and phloem through which water, nutrients and photosynthesized material can flow. Like mosses, liverworts reproduce with spores, not flowers and fruits. Having no vascular system, the flat, leafy bodies in the picture consist of flat layers of cells. A closer look at the bodies -- which among liverworts are known as thalli (singular thallus) -- is shown at https://www.backyardnature.net/n/15/151101lj.jpg.

As thallose liverworts go, this is a small-bodied species, its typical thallus width being only about 2mm (0.08 inch), as shown at https://www.backyardnature.net/n/15/151101lk.jpg.

It's unusual to find liverworts in this part of he world because of the long dry seasons. Reproduction in liverworts need moisture if only because their sperm must swim from male organs to female ones. It's also unusual to find loose, naked soil such as that on which these liverworts were growing. Pocket gophers had been throwing up hills in the area and it looked like the liverworts were colonizing an old gopher disturbance. And one has to wonder where the pioneering spores came from, since this is the first time I've seen them in all the Yucatan.

Since liverworts reproduce with dust-like spores that can be carried by the wind, their species often occur throughout much of the world. Without a microscope and reproductive material I can't identify this species with certainty, but I can say that it looks very much like one of the most common and widespread liverwort species in the world, one usually found on bare soil, often along footpaths and other disturbed areas, on both acidic and base-rich soils, and one that is thought of as easily recognizable because of its uniformly green, small thalli with a very conspicuous groove running down each thallus's middle, forming a Y where the thallus divides. And that species is RICCIA SOROCARPA. That name is an educated guess for what's in our picture, and nothing more, though Riccia sorocarpa has been recorded in Mexico, the Caribbean area and several tropical countries.

In England, Riccia sorocarpa sometimes is known as the Common Crystalwort, but most liverwort fanciers just call species of the genus Riccia Riccias.

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FEATURED ESSAYS FROM THE PAST:

"Cherry Wisdom" from the June 7, 2009 Newsletter, at https://www.backyardnature.net/n/p/090607.htm

"Occultism in the Mountains" from the August 9, 2009 Newsletter, at https://www.backyardnature.net/n/p/090809.htm

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Best wishes to all Newsletter readers,

Jim

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