JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from the valley of the Dry Frio River on the
southern slope of the Edwards Plateau, northern
Uvalde County, southwestern Texas, USA

July 20, 2014

PAPER WASPS
In mid-day heat at Cooks Slough Nature Park on Uvalde's south side I was so sweaty and tired of the sun's glare that when a small shelter beside Lunker Pond came along I lay onto the bench thinking about a little nap. But the instant before I closed my eyes, up in the rafters exactly above me, I saw what's shown at http://www.friocanyonnature.com/n/14/140720wa.jpg.

A close-up of a single wasp is at http://www.friocanyonnature.com/n/14/140720wc.jpg.

These looked like wasps that back in Mississippi might be inclined to sting if you move around too quickly and too close, and maybe are likely to go for a thick head of hair. I no longer have to worry about wasps getting into my hair, and in fact I was moving slowly that day, so I didn't mind too much having the wasps above me. In fact I was glad to see what seemed to be such a healthy colony forming.

I like paper wasps, which are wasps who build nests of paper, instead of digging burrows in the ground, daubing together nests of mud on walls, or building neat little mud "pots" to be hung in trees. One reason I like paper wasps is that I've seen so many forms of paper nests, especially in the tropics, and I enjoy seeing variations on any natural theme." Also, years ago when I was putting together the wasp page for the friocanyonnature.com website, a real wasp specialist, Dr. Joy Layton, offered to contribute very interesting information she had on the paper wasp life cycle. As is normal, the more you know about something in Nature, the more you appreciate it. You might enjoy Dr. Layton's remarks still online, starting about the middle of the page at http://www.backyardnature.net/wasps.htm.

In the shelter beside Lunker Pond I recognized our species with its ornate, yellow markings on a chestnut body as belonging to the genus Polistes, of which about 300 species are recognized.

Dr. Layton writes of Polistes wasps in general that each spring a single queen wasp, who mated the previous September or October, flies off and with no help from any other wasp starts building her nest, which at first is quite small, consisting of several paper-walled cells in the bottom of which her eggs soon hatch into grubs. Once the grubs need food, she leaves the nest unattended and flies around gathering caterpillars to feed her grub offspring.

Dr. Layton continues: "After about three to four weeks, these grubs pupate and emerge as new workers. They are all female and all sterile. Besides, there are no males alive to mate with anyway, so these workers will not lay eggs but will devote their lives to raising the next set of eggs of the queen."

That's what we're seeing in the first picture -- sterile female workers enlarging and tending the nest, a process that will continue all summer as the nest grows and more sterile female workers appear to increase the colony even larger. In the first picture note that at the bottom of the whiter cells at the lower, right in the picture you can see single eggs. White paper caps have been placed atop some of the egg-containing cells. At the lower left, among the dingier cells, you can see grubs needing to be fed. You can read what happens later in the season on our Wasp Webpage, though I can tell you now that it's a little sad, all the worker sisters dying, with only a few freshly produced males and some females destined to be the next season's queens flying off to mate.

Despite there being so many Polistes species, volunteer identifier Bea in Ontario feels fairly confident -- a distinguishing feature being the orange tips on our wasps' brown antennae -- that our shelter-rafter wasp is POLISTES EXCLAMANS, fairly common in the US southeastern states and northern Mexico, though it's been observed as far north as Missouri, Maryland, and New Jersey, and seems to be expanding its distribution northward, possibly as a result of global warming.

Polistes exclamans produces smaller nests than many other paper wasps, and appears to be especially vulnerable to predation and parasitization, resulting sometimes in the building of "satellite nests" around the main one. Someone has produced an especially detailed Wikipedia page on this species' life history at http://en.wikipedia.org/wiki/Polistes_exclamans.

******

SHORT-WINGED KATYDID
Atop a wild sunflower's mature fruiting-head a particularly handsome green-cricket sort of critter with a curved back and outlandishly long antennae was wandering about, as seen at http://www.friocanyonnature.com/n/14/140720kd.jpg.

From it's oversized rear jumping legs and grasshopper-like head with chewing mouthparts I could see that the insect was a member of the Order Orthoptera. However, several times in this Newsletter we've seen that boundaries between the grasshoppers, crickets and katydids who populate the Orthoptera can be obscure. This individual was one who needed at least a little analysis to figure out which group it belonged to. All the grasshoppers I know fold their straight wings neatly over their backs, giving their bodies straight-backed profiles, and since our sunflower visitor's back is not at all straight, and its antennae are too long as well, I figured it wasn't a grasshopper. Crickets normally have flatish bodies, not broadly humped ones like ours, so on that basis I decided we had a katydid. But there's a whole universe of katydids and katydid-like relatives.

Focusing on the wings, our individual turned out to have nothing but tiny, white, lacy, scale-like things emerging from behind the pronotum, which is the big, saddle-shaped scale immediately behind the head, as shown at http://www.friocanyonnature.com/n/14/140720ke.jpg.

Such tiny wings could never serve for flying. We've seen wings like this on immature insects, but this individual appeared to be a mature female with a well formed, swordlike ovipositor (egg-layer) at her rear end, shown at http://www.friocanyonnature.com/n/14/140720kf.jpg.

Volunteer identifier Bea in Ontario decided that we had one of several species of short-winged katydid, genus Dichopetala, and that explained what was going on. For, in that genus the males possess short forewings enabling them to fly, but females are flightless because they only have those lacy scales seen in our picture. Short-winged katydids of the genus Dichopetala occur only in the Americas, where 22 species are known, with eight listed for North America. So, which one is ours?

The University of Florida provides a wonderful page entitles "Checklist of Katydids North of Mexico," at http://entnemdept.ifas.ufl.edu/walker/buzz/katylist.htm.

On that page when you search for the genus Dichopoetala you see the names of the eight species known for North America, and what's so great about this page is that each name is linked to another page providing pictures of pinned specimens of that name, drawings showing features critical for identification, and a distribution map. Someday maybe all plants and animals will be honored with such pages, but so far few are.

Mainly on the basis of the shape of its "subgenital plate" I'm calling our katydid the Chestnut Short-winged Katydid, DICHOPETALA CASTANEA. Its University of Florida page is at http://entnemdept.ifas.ufl.edu/walker/buzz/095a.htm.

On that page you can see that Dichopetala castanea's subgenital plate is broadly rounded along the side, very different from the plates of other listed species. On our picture of the ovipositor, the side of one subgenital plate can be seen below and at the very base of the ovipositor. The plate is green, and its side is broadly rounded just as in the drawing. Also, the drawing of Dichopetala castanea's ovipositor matches ours perfectly, while the ovipositors of other species are narrower and not curved exactly like ours.

Our Chestnut Short-winged Katydid appears to be narrowly endemic just to southwestern Texas and arid northeastern Mexico. Moreover, all short-winged katydids -- all species of the genus Dichopetala -- occur only in Mexico north of the south-central state of Guerrero, north into the US from north-central Texas to central southern Arizona. If you want to see in the wild a female short-winged katydid with her lacy little wing-buds, you just have to come to this part of the world.

Little is known about the species. Now we can inform the world that in mid July mature females wander about sunflower fruiting heads next to ponds in Cooks Slough Nature Park on Uvalde's south side, Uvalde, Texas.

*****

TREE OF HEAVEN
Biking through Uvalde a tree caught my eye enough for me to put on the breaks and go back for a second look. The tree's leaves were similar to those of native and abundantly planted Pecan trees, but this tree was loaded with dense clusters of wafer-like fruits looking nothing like pecans. You can see the leaves and fruits at http://www.friocanyonnature.com/n/14/140720al.jpg.

A closer look at the samara type-fruits -- samaras being winged fruits that don't split open at maturity -- is at http://www.friocanyonnature.com/n/14/140720am.jpg.

Back East I got to know this tree during my earliest tree-looking days, for it's often planted in towns and sometimes becomes invasive, pushing aside native trees and forming dense colonies just of itself. In cities it's often planted because it'll grow where other trees won't. The novel A Tree Grows in Brooklyn is referring to this tree. It's the Tree of Heaven, but because of its aggressiveness and stink sometimes it's derisively called "Ghetto Palm", or even "Tree of Hell."

Whatever English name it goes by, it's AILANTHUS ALTISSIMA, native of China and a member of the smallish Quassia Family, the Simarubaceae, whose trees and shrubs occur worldwide but mostly in the tropics. The Tree-of-Heaven has become so well known as an urban tree able to thrive in bad soil and air pollution, and as a weed tree in wilder areas, that it's by far the best known member of its family.

In China it's an important tree. The oldest existing Chinese dictionary, written in the 3rd century BC, mentions the Tree-of-Heaven and in traditional Chinese medicine it's been used for ailments ranging from mental illness to baldness. The roots, leaves and bark are still employed today, and all you have to do to smell the tree's medicinal odor is to brush your hand against the leaves, causing a penetrating, musky, oily odor to fog around you. If you look at leaflet bases you'll see glands, shown at http://www.friocanyonnature.com/n/14/140720an.jpg.

Tree-of-Heavens do produce some interesting compounds, including some that are "allelopathic," which means that they retard the growth of, or kill, other plant species in the vicinity. This explains why sometimes you find pure stands of Tree-of-Heavens. The effect is so pronounced that the possibility has been mentioned of using Tree-of-Heaven root extract in water as a natural herbicide.

Tree-of-Heaven also has been grown extensively in China and many other countries as the host plant for the Ailanthus Silkmoth, from whose cocoons silk can be taken.

Betty Smith writes of the Tree-of-Heaven in A Tree Grows in Brooklyn that ... "It grows lushly...survives without sun, water, and seemingly earth. It would be considered beautiful except that there are too many of it.

*****

PIGEONBERRY
In blinding, mid-day light with the temperature nudging a hundred, my eye still caught a tiny flash of bright red about a foot off the ground, deep inside a dense hedgerow at the edge of Cooks Slough Nature Park on Uvalde's south side. On hands and knees I crawled into the tangle and was surprised by whom I found there. You can see the pretty little plant with its 1/8th-inch-broad (3mm), red berries at http://www.friocanyonnature.com/n/14/140720rv.jpg.

A close-up of some berries along with several old calyxes and stamen filaments where the juicy fruits have been critter-snatched, is at http://www.friocanyonnature.com/n/14/140720rw.jpg.

This is an old friend from the Yucatan, a pretty species turning up again and again along trails through the shadowy, scrubby woods around Chichén Itzá and around my old hut. II had no idea it occurred this far north. In English it's called Pigeonberry, Rouge Plant, Baby Peppers and other names. It's RIVINA HUMILIS, and if you pay attention to the fruiting head's general appearance and the succulent berries you'll have no trouble believing that Pigeonberry is a member of the Pokeweed Family, the Phytolaccaceae. Doesn't its slender raceme of fruits remind you of a Pokeweed's narrow, curving fruiting heads, each little berry on its own short stem, or pedicel?

Our Pigeonberry wasn't flowering, but you can see flowers on a plant near my hut back in the Yucatan at http://www.backyardnature.net/yucatan/pigeonby.htm.

Our hedgerow Pigeonberry struck me as an herb not over knee high, but I know from the Yucatan that it can grow head-high, and its stems arise from perennial, woody bases. It loves shade modestly dappled with flecks of sunlight, both up here and in the Yucatan.

The plant looks delicate, and that day in the heavy heat its leaves crinkled and wilted in the dry air, but this is a tough species, as can be believed from its extensive distribution area stretching from Argentina in South America through all of tropical America into the US from Arizona to Florida as far north as Oklahoma. It's also become invasive in the Old World, where it's often been introduced into gardens because of its prettiness, its medicinal uses, and, especially, the use of juice from its red fruits to redden lips, cheeks or whatever part of the body needing reddening -- thus the other common name "Rouge Plant."

Delena Tull in her 1999 book Edible and Useful Plants of Texas and the Southwest: A Practical Guide says that all parts of the plant are considered toxic, "with toxicity similar to that of its larger relative poke." I've nibbled on ripe fruits of both Pigeonberry and Poke, found them similarly as bitter as they are tasty, and never have suffered any ill effects. I never eat many, though.

*****

PRICKLY LETTUCE
Nowadays in town along sidewalks, up against warehouses, in abandoned lots and such, one of the scraggliest, most overtly weedy-looking, but nonetheless interesting and worth noticing herb is the one shown at http://www.friocanyonnature.com/n/14/140720lc.jpg.

That spindly plant bears widely spaced, deeply lobed leaves somewhat like dandelion leaves, and if you tear this plant's leaf it issues white latex, or "bleeds milk," also like dandelion leaves. In fact, though dandelions produce only one white, puffball-like fruiting head, each of our weed's many thumnail-sized heads also look like a miniature dandelion head, as shown at http://www.friocanyonnature.com/n/14/140720ld.jpg.

In that picture notice how each white "parachute" unfurls atop a long, slender "neck" leading to a curved, brown item at the base, the cypsela-type fruit, also like that of the dandelion. If our weed were flowering we'd see that its flowers consist of heads of yellow ray flowers, also like the dandelion.

In other words, our weed is closely related to dandelions, both being members of the huge Composite or Sunflower Family, and the same "tribe," the Cichorieae, whose members produce flowering heads consisting only of ray flowers with flat, strap-like corollas, and whose herbage normally issues white juice when injured. Our plant's yellowish flowers have already passed but you can see its urn-shaped involucres containing maturing fruits before opening up to form the "puffball" seen above, at http://www.friocanyonnature.com/n/14/140720lf.jpg.

Our weed is one of several plants known as Prickly Lettuce. It's LACTUCA SERRIOLA, a native of Eurasia but now found nearly worldwide in disturbed places, and coast to coast in North America. In North America this species can best be distinguished from other wild lettuces by its occurrence in very abused soil, and its distinctive, lobed leaves, one of which is shown at http://www.friocanyonnature.com/n/14/140720le.jpg.

Notice how that leaf twists so curiously twisted; more about that below. Also, the leaves' bases are distinctive because they extend backwards from the leaf, making pointy little "ears" snuggled around the stem, as shown at http://www.friocanyonnature.com/n/14/140720lg.jpg.

Finally, on Lactuca serriola's leaf undersurfaces the midveins are armored with sharp little prickles, pictured at http://www.friocanyonnature.com/n/14/140720lh.jpg.

But, to return to the strange twistiness shown by the earlier leaf. Sometimes Lactuca serriola is known in English as the Compass Plant because the plant's upper leaves exhibit a very interesting "heliotrophism" enabling them to better survive under hot, sunny, dry conditions. Exactly as our picture shows, they twist so as to orient themselves parallel with the sun's rays, thereby decreasing leaf temperature and minimizing water loss.

Lactuca serriola is very closely related to the wild ancestor of our garden lettuces, so it's no surprise that its young leaves can be eaten either raw or cooked. Older leaves, however, such as those on our plant, are too bitter and coarse to fool with.

Traditionally the species has been used medicinally in various ways, its white latex containing the compound lactucarium, sometimes called "lettuce opium," which an old herbal describes as having "the effects of a feeble opium" -- mainly as a sedative. Overdoses on lactucarium, though, as with opium, can cause death through cardiac paralysis. Young plants whose leaves we might eat contain only small amounts of lactucarium, however, plus the compound is more concentrated in older plants, and in other Lactuca species.

*****

GAMAGRASS FRUITS
In May we looked at the big Eastern Gamagrass, Tripsacum dactyloides, thriving at the edge of a pond in Cooks Slough Nature Park on the south side of Uvalde. Our Gamagrass page profiling that handsome grass is at http://www.friocanyonnature.com/n/h/gama.htm.

Now the plant's very unusual-looking and large grains are maturing, as shown at http://www.friocanyonnature.com/n/14/140720tr.jpg.

Grains break from the spikes' tips, each grain forming a cylindrical, tin-can-like affair with a little eye-like feature at its base. Much of the cylinder is actually part of the stem segment that falls with it, which you can visualize better by looking at pictures showing the rachis on our Gamagrass Page.

Even with this stem material attached, the "seeds" are favorite food for deer and birds. Each plant produces so few seeds that one suspects that the few seeds who do survive to sprout have a good survival rate.

*****

INDIAN-FIG PRICKLYPEAR CACTUS
In Mexico we've seen plenty of the thornless, highly edible Indian-Fig Pricklypear cactus, also known as the Nopal Cactus if you're thinking of eating the green pads, and Tuna Cactus if you have in mind eating the spherical fruits, called tunas. It's Opuntia ficus-indica and our page profiling a tree-like individual in the Yucatan is at http://www.backyardnature.net/mexnat/nopal.htm.

Behind the red cabin the valley of the Dry Frio River where I lived my first winter here, there was another edible, spineless pricklypear species, Opuntia ellisiana, in these parts often confused with Indian-Fig Pricklypear. It's profiled at http://www.friocanyonnature.com/n/w/no-spine.htm.

I'd supposed that here in southwestern Texas we were too far north for the Indian-Fig to be cultivated, but this week along a backstreet in Uvalde, which is 35 miles south of us and situated on the Coastal Plain at a lower elevation than the Dry Frio valley, and therefore somewhat warmer throughout the year, a real Indian-Fig turned up robustly sprawling onto a weedy sidewalk, even bearing flowers, as shown at http://www.friocanyonnature.com/n/14/140720o0.jpg.

Not only yellow flowers but also small, tender pads were emerging, some of them perfect for plucking off, slicing, sautéing with onion, tomato and chili, sprinkling with lime juice, and eating. You can see tender little pads emerging from a large mother-pad at http://www.friocanyonnature.com/n/14/140720o1.jpg.

That mother-pad displays broad, irregularly scalloped margins and a fanlike system of low ridges originating at its base unlike anything I've seen in Mexico. However, the inner pads are huge just like those I'm familiar with, as shown at http://www.friocanyonnature.com/n/14/140720o4.jpg.

To be absolutely sure I had a real Indian-Fig the flowers were examined. A side view of one appears at http://www.friocanyonnature.com/n/14/140720o3.jpg.

A peep into the blossom's interior showing many pollen-producing stamens surrounding several yellow, finger-like stigma lobes in the center is at http://www.friocanyonnature.com/n/14/140720o2.jpg.

The yellow stigma lobes are significant. Stigma lobes of the other edible, spineless cactus we have, as you can see on the page linked to above, are pale green. Indian-Fig stigma lobes are yellow, exactly as in the picture. This is truly the real Indian-Fig thriving this far north.

It's not too surprising that Uvalde's Indian Fig should display features I've not seen before because there are lots of cultivars. The Flora of North America tells us that:

"This species probably originated through selection by native peoples of Mexico for spineless forms of Opuntia streptacantha (also 2n = 88) to ease the culturing and collection of cochineal scale insects for their red dye. Numerous cultivar names are known."

We've discussed cochineal dye at http://www.backyardnature.net/n/a/cochinea.htm.

So, current thought is that centuries ago indigenous Americans probably in south and/or central Mexico learned that by squishing certain little white, wingless insects feeding on the wild-growing, spine-possessing cactus Opuntia streptacantha, they could acquire a brilliantly red dye, which they wanted more of. As time passed people began cultivating the cactus to make dye gathering easier, and for the parent cactus stock naturally they chose the least spiny individuals they could find. Ultimately this led to a new, human-made, spineless cultivar, which eventually contributed lots of genetic material to the modern Indian-Fig.

However, there's not a direct line from wild Opuntia streptacantha to today's Indian-Fig. Gene sequencing analysis indicates that several different spiny pricklypear species have contributed to the Indian-Fig's genes. You might enjoy reading the whole story in a paper entitled "The origins of an important cactus crop, Opuntia ficus-indica (Cactaceae): new molecular evidence," in an online 2004 edition of the American Journal of Botany, archived at http://www.amjbot.org/content/91/11/1915.full.

What a pleasure meeting this old friend and being reminded of what a colorful history it has.

*****

Best wishes to all Newsletter readers,

Jim

All previous Newsletters are archived at http://www.friocanyonnature.com/n/.