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

October 13, 2013

BUSH KATYDID
Some of my raised beds at the red cabin are so "weedy" with wild purslane that I didn't sow mustard or turnip greens in them -- because the wild purslane itself is even more nutritious and as good tasting as regular greens. So, early one morning I was picking greens when what I thought was a sprig of purslane jumped as I reached for it. You can see the critter at http://www.backyardnature.net/n/13/131013kd.jpg.

A neat close-up of the head showing very complex mouthparts for chewing is at http://www.backyardnature.net/n/13/131013ke.jpg.

In the first picture you may have noticed that emerging from the rear end was a brown, scythe-shaped, blade-like item. A close-up of that is at http://www.backyardnature.net/n/13/131013kf.jpg.

Probably you recognize this insect as a kind of katydid, and a female one at that, since the brown item at the rear end is the ovipositor used by the female to insert eggs into various places. Volunteer bug identifier Bea in Ontario pegs this as the Fork-tailed Bush Katydid, SCUDDERIA FURCATA, variably colored and commonly occurring throughout most of the US and adjacent Canada, south through Mexico and Central America into northern South America.

In the last picture you might have noticed at the base of the ovipositor something looking like a tiny, hairy, brownish, pointy-headed grub emerging from the same split as the ovipositor. Bea says that these as "cerci," and passes along her reading that "Cerci often serve as sensory organs, but they may also be used as weapons or copulation aids, or they may simply be vestigial structures." Seeing our katydid's cerci, I wondered whether they might enable the female to "smell" the thing she was about to lay her eggs in, and I still think that that's a good bet, though I can't find research claiming it to be so.

We've run into the Fork-tailed Bush Katydid's very attractive and interesting looking nymphal stage in Mississippi, which you can see at http://www.backyardnature.net/n/08/080707ny.jpg.

The University of Florida provides pictures and audio files of the Fork-tailed Bush Katydid's call at http://entomology.ifas.ufl.edu/walker/buzz/063a.htm.

The University of Florida also provides a "Checklist of Katydids North of Mexico" with links to pictures and information about a mind-boggling number of species, which is fun to browse, at http://entomology.ifas.ufl.edu/walker/buzz/katylist.htm.

Over 6,400 katydid species are recognized, eating mostly leaves, flowers, bark, and seeds, but many species are exclusively predatory, feeding on other insects, snails and even small vertebrates such as snakes and lizards.

*****

PRICKLYPEAR BUG
I was botanizing with a friend when we spotted an insect on a pricklypear cactus. It was an immature bug, a nymph, and I'm using the word "bug" in its more technical sense, referring to a member of the True Bug Order, the Hemiptera. You can see the nymphal bug with its hardly developed wings but very large, unusual antennae, wandering across a pricklypear pad, at http://www.backyardnature.net/n/13/131013ny.jpg.

While snapping the above picture I told my friend that our volunteer bug identifier, Bea in Ontario, would be tickled to see such a singular-looking bug. My friend replied, having no idea what the bug's identify might be, "Watch the common name turn out to be Pricklypear Bug... "

That's exactly what happened. Our picture shows a Pricklypear Bug, CHELINIDEA TABULATA, found from Texas and California south through Mexico and Central America into northern South America. In Australia it's been introduced as a biological control agent in an attempt to control American pricklypears who have escaped and become serious weeds.

The Pricklypear Bug isn't to be confused with the Cactus Bug, which we've introduced at http://www.backyardnature.net/n/a/cactusbg.htm.

Nymphs of that somewhat-closely-related species are bright red and they tend to cluster in groups, while our nymph not only is green but also all ranged all alone on his pricklypear. These are consistent behavioral differences between the two species.

*****

BEE FLY
Each morning several honeybees visit the flowering Purple Spiderwort on Juniper House's deck, gathering pollen. Only occasionally do bee flies come. You can see one hovering at the edge of a flower, probing a pollen-filled yellow anther with his clublike, sponging-type probosis, and his wings moving so fast that they appear only as blurs, at http://www.backyardnature.net/n/13/131013bf.jpg.

The same fly at rest, displaying distinctive, partially pigmented wings, is at http://www.backyardnature.net/n/13/131013bg.jpg.

Volunteer identifier Bea in Ontario feels that probably we have the Sinuous Bee Fly, sometimes called the Chocolate Bee Fly, HEMIPENTHES SINUOSA. That's a common species throughout most of North America, but Bea says so many species are recognized that she can't be perfectly sure of the ID. The design created by the pigmentation on our fly's wings so perfectly matches those of the Sinuous Bee Fly that I'm filing this page under that name, knowing that eventually an expert will confirm or correct it. The important thing is to document the fly here at this time doing what it's doing.

You can see that this is a fly and not a bee, because bees have four wings, but flies like our critter have only two.

Bee flies of this genus are parasitoids and hyperparasitoids. Parasitoid species are those whose mode of life is intermediate between being a parasite and a predator. In this case it means that parasitoid bee fly larvae are parasitic on another species, but the adult visits flowers.

The term hyperparasitoid refers to the fact that our bee fly's larvae hatch within the larval stage (caterpillars) of tachinid flies, ichneumon wasps and other species, which themselves are parasitic in other species. In other words, larvae in this genus are parasites of parasites of other animals...

*****

SANDPAPER OAK WITH ACORNS
This March we looked at head-high, bushy Sandpaper Oaks growing in thin, dry soil atop our limestone hill. At that time the trees were flowering and the leaves weren't fully developed. You can see this at http://www.backyardnature.net/n/w/qpungens.htm.

Now those bushes are bearing handsome acorns and interesting leaves, as seen at http://www.backyardnature.net/n/13/131013qu.jpg.

A close-up of the acorns appears at http://www.backyardnature.net/n/13/131013qv.jpg.

Because of pictures and drawings I've seen of Sandpaper Oak acorns, I was surprised that our bushes produced acorns with such long nuts. However, the Flora of North America describes the nuts as "broadly ovoid to subcylindric." "Subcylindric" is the same word the expert uses to describe the acorns of the Shin Oaks we looked at last week, and the acorns of that oak were very similar to our Sandpaper Oak's. When identifying oaks in our area, the challenge is to distinguish Sandpaper Oaks from Shin Oaks. And, this is keeping in mind that they hybridize.

In the Flora key, leaf margins of Sandpaper Oaks are described as "strongly undulate," meaning that the margins are wavy, curving up and down relative to the blade's plane. Our first picture portrays leaves with very undulating margins. You can contrast those leaves with the Shin's Oaks, which are described as "planar," or flat, on our Shin Oak page at http://www.backyardnature.net/n/w/shin-oak.htm.

*****

BRICKELLBUSH
All summer, right at Juniper House's door, a certain low bush with dark, green leaves has been developing. It was such a robust, well proportioned and somehow comely plant that several people asked what it was, but I didn't know. I had to wait for the flowers. Flower buds appeared about two weeks ago, and now the plant is in full bloom. You can see a waist-high clump with its much-branched, soft-woody base at http://www.backyardnature.net/n/13/131013bk.jpg.

Branch tips are heavy with narrow flower clusters of the kind found in the Composite or Sunflower family, but consisting only of cylindrical disc flowers without petal-like ray flowers, as shown at http://www.backyardnature.net/n/13/131013bl.jpg.

A flower head up close shows that a head's few disc flowers are held within a narrow involucre consisting of scale-like phyllaries that at the base of the involucre are short and fuzzy but at the top are long and hairless, as shown at http://www.backyardnature.net/n/13/131013bo.jpg.

In that picture, the slender, yellow items bending from the disc flowers' five-toothed crowns are style branches, reaching out to capture pollen.

A few weeks ago someone stepped on a plant, causing it to wither and unseasonably early produce parachuted, cypsela-type fruits, as shown at http://www.backyardnature.net/n/13/131013bn.jpg.

In that picture, notice how the long inner phyllaries gracefully peel back, presenting the cypselae as in a floral arrangement. The cypselae's parachutes help in wind dissemination.

The Flora of North America says that the species' leaves are "mostly opposite, sometimes alternate or subopposite," but ours tend to be mostly alternate. Some are shown close-up at http://www.backyardnature.net/n/13/131013bm.jpg.

Books often refer to this plant as the Leafy Brickellbush. It's BRICKELLIA CYLINDRACEA, endemic only to a few counties in central Texas. It's a wonderful find, and I'm honored to have such an uncommon species growing so lustily right beside my door.

About a hundred species of brickellbushes -- or members of the genus Brickellia -- are recognized, living in Central America, Mexico, and the US. In the US 32 species are known, mostly in the desert Southwest. In our area, two other brickellbush species are to be expected, and one, Brickellia dentata, is very similar. However, it's described as living on gravel of limestone streambeds, while our Leafy Brickellbush is limited to dry limestone hillsides, exactly where we are. The third species, Brickellia eupatorioides, lacks the short, roundish, lower phyllaries in the involucre, plus the white hairs forming its cypselae's parachutes are branched and featherlike, not simple hairs like ours.

This handsome, perennial bush with dark green leaves certainly would be a fine addition to any xeriscaped garden in arid country.

*****

GREEN SPRANGLETOP GRASS
One of the most common and conspicuous grasses not only around Juniper house but also along roads, growing about waist high, is the one shown at http://www.backyardnature.net/n/13/131013lp.jpg.

For a couple of weeks its immature flowers have been pushing up from leaf clusters, looking like narrow spikes. However, as the inflorescences rose it began unfolding side-arms that now are held at right angles to the stem axis. You can see two spikelets at http://www.backyardnature.net/n/13/131013lq.jpg.

There you see that each spikelet holds three or four florets. That's an important field mark because many grasses bear just one floret per spike, while others have dozens. A close-up of just one spikelet with its florets teased apart so that the lemma tips are visible is at http://www.backyardnature.net/n/13/131013ls.jpg.

Lemmas are the larger scales folding around the sexual parts of individual florets. Basic terms applying to grass flower anatomy are explained on our Grass Flower page at http://www.backyardnature.net/fl_grass.htm.

The above photo showing lemma tips displays a very important field mark for this species, which is that the tips are flat, even somewhat cleft in their centers. Lemma tips of the vast majority of grass species are sharply pointed, so such flat-tipped ones are just outrageous -- and helpful in the identification process.

Another field mark is the grass's ligules -- the ear-like appendages occurring where blades meet the stem. Many ligules are fence-like rows of stiff hairs, or cellophane-like barriers, or some other way, and many species don't have ligules at all. You can see this grass's modest ligules at http://www.backyardnature.net/n/13/131013lr.jpg.

Despite all these fine field marks, I had trouble keying out this abundant grass. Therefore this weekend I was glad when botanist Fred Wills visited from San Antonio, and I could just ask him what it was. "Green Sprangletop," he replied, which was a name I'd never heard of. "Sprangletop" sounds like a good Texas name, "sprangle" meaning "spread out in different directions," and our grass's inflorescence arms do that. Normally I look up the scientific name to get the common name, but this time I did the opposite. Several species known as sprangletops turned up with an image search, but only one image matched our grass. It was LEPTOCHLOA DUBIA.

Green Sprangletop occupies dry, open plateaus and hills, alluvial areas, hammocks, and even disturbed areas throughout most of the Americas. It's a larval host the Sheep Skipper and Olive-clouded Skipper butterflies.

Ecologically, Green Sprangletop behaves as a pioneer species, so often it's used in seed mixtures so it can form a quick groundcover while other species have time to get established. However, the species is intolerant of poorly drained soils and high water tables.

*****

OYSTER MUSHROOM
It's so arid here that we don't see many fleshy mushrooms. However, a good one turned up in the yard of my neighbor Phred, where he waters his pumpkins once or twice a day. The mushrooms grew in a cluster on a tree stump in the shade of big pumpkin leaves. Phred collected the mushrooms and handed them to me before I could get a picture, so you can see what they looked like in my hand at http://www.backyardnature.net/n/13/131013pl.jpg.

Notice how the gills on the caps' bottom surfaces extend onto the thick stems. A shot from above showing the caps' brownish blush is at http://www.backyardnature.net/n/13/131013pm.jpg.

This is one of the most common, easy-to-identify and best known of all mushrooms in North America and northern Eurasia, the Oyster Mushroom, PLEUROTUS OSTREATUS.

When I was a kid, because Oyster Mushrooms are so easy to identify, they were the first wild mushrooms I had enough nerve to eat. Once I'd nibbled one to be absolutely sure I wasn't going to die, I ate a little more, and when nothing happened, then I went pig wild. On our farm we had several dying cottonwood trees whose trunks were loaded with them. I'd melt a dollop of butter in a big skillet, cover the skillet's bottom with Oyster Mushrooms, then once everything was well fried I'd sprinkle on salt and pepper, and that was some of the most memorable eating of my life.

Actually, there's a good chance that what I ate wasn't the real Oyster Mushroom. That's because nowadays they've realized that what we've always thought of as one big, variable species actually consists of several. Happily, all the species can properly be called Oyster Mushrooms, and all are edible. One of the other species, Pleurotus populinus, specializes on growing on poplars, and cottonwoods are poplars. That looks like the "real" Oyster Mushroom in our picture.

Oyster Mushrooms live both on dead trees and logs, where they're "saprobic," and on living trees, in which case they are parasitic, and cause a white rot disease. Curiously, Oyster Mushrooms kill nematodes and bacteria in the rotting wood they live in.

I placed Phred's mushrooms on a table for a few hours before chopping them into an omelet. During that time, white spores fell from gills beneath the cap onto the dark table top. You can see the resulting accidental "spore print" at http://www.backyardnature.net/n/13/131013pn.jpg.

Often when identifying mushrooms I make spore prints to see what color they are, for some species produce black spores while others may produce gray or green ones, or spores of other colors. You can see that Oyster Mushrooms produce white spores.

*****

JUPITER IN GEMINI
Each morning a little before dawn when I step outside to begin my jog, if a clear day is in store, I'm greeted by a dazzlingly starry sky. Right overhead it's easy to make out the constellation Orion with its five bright stars defining the hunter's head, shoulders and feet, and smaller stars making his belt and sword. We've looked at Orion at http://www.backyardnature.net/n/x/orion.htm.

As I run southward, part of the sky just to the left, or east, of Orion's shoulder is dominated by the sky's brightest-of-all-stars, the Dog Star, Sirius. Sirius displays a "visual apparent magnitude" of -1.46 -- the lower the number, the brighter the star. Sirius is almost twice as bright as the sky's second brightest star, Canopus.

However, on these October mornings, something in the sky not too far from Sirius, and which isn't the Moon, is even brighter than Sirius. It shines with a dazzling apparent magnitude of -2.3. It's the planet Jupiter.

Nowadays Jupiter lies within the constellation Gemini, known as "The Twins" in English. A time exposure, with the left side of the picture showing Jupiter glowing brightly more or less in the center, and the left side displaying the same part of the sky but with Gemini's structure drawn in, and with some labels added, is shown at http://www.backyardnature.net/n/13/131013gi.jpg.

In that photograph -- with north at the top -- Pollux forms the head of the twin on the left, while Castor designates the head of the other twin. Pollux is a giant star with a visual magnitude of 1.1, and is about 33.78 light-years from Earth. Castor is actually more than one star. It's a sextuple star system (six stars) 52 light-years from Earth, with a magnitude of 1.6. You can see that Jupiter right now inhabits the place where the legs of the twin on the left come together.

M35 is a star cluster that's hardly visible in the picture, and I can't make it out with my naked eyes as I run. It should show up with binoculars, however. It consists of about 200 stars arranged in chains curving throughout the cluster, and it's about 2800 light-years from Earth. Since our galaxy, known as the Milky Way, is 100,000–120,000 light-years in diameter, M35 is a relatively near part of our own galaxy. You can see M35 and read about it at http://messier.seds.org/m/m035.html.

Wikipedia's Gemini page has much more information about the constellation Gemini and objects found in it at http://en.wikipedia.org/wiki/Gemini_(constellation).

As the months pass, it'll be interesting to watch Jupiter slowly wander across the sky. My star-chart program shows that this time next month it'll still be in Gemini, but a bit to the left, or east, of where it is now. Its normal direction is toward the east, relative to the star patterns behind it. However, on November 7th of next month, Jupiter will appear to stand still, then begin moving backwards, or in "retrograde motion," toward the west. It'll continue in retrograde westward motion until March 6, 2014, when it'll appear to turn around once again, and return to heading east. Of course Jupiter isn't really turning around -- it just appears so from Earth as both Earth and Jupiter orbit the sun at different speeds. A webpage doing a nice job explaining all this is at http://earthsky.org/tonight/jupiter-appears-to-stop-then-change-direction.

It takes 11.86 Earth years (or 4332 days) for Jupiter to orbit the Sun.

*****

JUNIPER PARADOX
Many landowners in this area feel that if they allow Ashe Junipers to grow on their property they are being bad neighbors. That's because, they tell you, the junipers -- called "cedars" here -- "suck up" vast amounts of water, and are an invasive species that came into the area maybe 40 years ago. Many landowners spend a lot of money to have their junipers cut, heaped into piles, and burnt. I've had no luck convincing anyone that, in fact, Ashe Junipers are a native, co-dominant species in our natural Liveoak-Juniper forests, and that they don't use more water than other species.

This week a friend brought to my attention a 2010 paper by B.P. Wilcox and Y Huang entitled "Woody plant encroachment paradox: Rivers rebound as degraded grasslands convert to woodlands," appearing in Geophysical Research Letters 37. The "degraded grasslands" in the title are mainly ranchland overgrazed by cattle and/or goats, and the "woody plant encroachment" is mainly encroachment by Ashe Junipers.

Having analyzed stream-flow trends of four major rivers over a period of 85 years here in the Edwards Plateau, this was their conclusion:

"... contrary to common and widespread perceptions, streamflows have not been declining. In fact, the contribution of baseflow (supplied by springs and groundwater) has doubled —- even though woody plant cover has expanded and rainfall amounts have remained relatively constant."

You can read the paper's abstract for free, or buy the paper in PDF format, at http://onlinelibrary.wiley.com/doi/10.1029/2009GL041929/abstract.

*****

JUNIPER GROUP POLARIZATION
While thinking about why people kill their Ashe Junipers, saying that the trees "suck up" too much precious water and are invasive -- despite studies showing the opposite -- I came upon the concept of "group polarization." Polarization occurs when a group makes decisions that are more extreme than the initial inclination of its members. Wikipedia goes further into the matter at http://en.wikipedia.org/wiki/Group_polarization.

One explanation for why group polarization takes place is called the "social comparison theory." It postulates that when people belong to a group they pay attention to how others think. In order to gain acceptance, they take positions similar to everyone else’s, but a little more extreme, thus not only making clear that they agree with the group’s beliefs, but even that they are to be admired for "leading in the right direction."

That theory sounds right to me, and my experience is that normally polarized groups go beyond that. For example, around here my impression is that those most aggressively ridding the landscape of junipers belong to a polarized group consisting of folks conspicuously championing conservative traditional values -- flags by doors, quoting Bible verses, etc.

I'm guessing that conservative traditional values and killing junipers got lumped together because cattle need grasslands, not juniper woods, and in this area cattle and goat ranchers, who normally are conservative folks with traditional values, are much esteemed. People see ranchers clearing junipers, even receiving government subsidies to help them do so, so if ranchers and the government are against junipers, other "good, all-American citizens" also should be against junipers.

The polarization of groups who lump unrelated issues is dangerous. By definition, group polarization works against following The Middle Path. Though humans are born with a rainbow of differing, genetically based biases and needs, healthy societies average out those often-conflicting impulses into societal norms and behaviors more or less distributed along The Middle Path. During human evolution, until now, that Middle Path has been a sustainable one.

What happens when The Middle Path is abandoned? We'll see what happens to the US if Congress continues avoiding the Middle Path. The thing that happens when members of a polarized group kill junipers because they wish to be good neighbors is that soil erosion results; aquifers get plugged with sediment from the erosion; sunlight-glare-absorbing, cooling, oxygen-producing greenery and wildlife cover are removed from the landscape, and; beautiful, worthy, natural beings meant to live exactly here are destroyed on the false grounds that they "suck up water" and are invasive.

This isn't to say that junipers should be allowed to grow everywhere. Historically, juniper numbers were controlled by occasional large fires. However, with roads and fenced-in ranches, now such fires are suppressed and junipers can take over to the exclusion of nearly everything else. Sometimes the removal of junipers actually results in increased biodiversity.

In our area The Middle Path with regard to Ashe Junipers would lead to a landscape mosaic where junipers are cleared from some areas, but in others are granted sanctuary. Here in the recharge zone of important aquifers, juniper woodlands would be honored for contributing to the aquifers' recharge. But, nowhere would junipers be killed just because that's what's done by good, all-American neighbors.

*****

FEATURED ESSAYS FROM THE PAST:

"On the Ecology of Human Diversity" from the August 28, 2005 Newsletter, at http://www.backyardnature.net/n/p/050828.htm

"Why Destruction Might be So Much Fun" from the May 9, 2004 Newsletter, at http://www.backyardnature.net/n/p/040509.htm  

*****

Best wishes to all Newsletter readers,

Jim

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