JIM CONRAD'S
NATURALIST NEWSLETTER
Issued from the woods a few miles east of
NATCHEZ, MISSISSIPPI, USA

August 19, 2012

SEVEN-SPOTTED LADYBUG
On a head-high Sesbania beside a flooded wildlife field in St. Catherine Creek National Wildlife Refuge just south of Natchez a bright red ladybug caught Karen's eye, and she pointed it out to me. You can see the bug at http://www.backyardnature.net/n/12/120819la.jpg.

I'm always glad to see ladybugs because they are such important insects, voraciously preying on aphids and other plant-damaging invertebrates, plus ladybug numbers have plummeted, as made clear at the LostLadybug.Org website at http://www.lostladybug.org/.

I'm also glad to find ladybugs because on the Internet there's a wonderful, free, well illustrated, interactive identification key, at http://www.discoverlife.org/20/q?guide=Ladybug.

With that fun-to-use key I figured out that our Sesbania-perched ladybug was the Seven-spotted Ladybug, COCCINELLA SEPTEMPUNCTATA, an alien species introduced into the US from Europe in 1956. In Europe Seven-spotteds are the most common ladybug species. One reason it's become so widespread in the US is that it's been repeatedly introduced here as a biological control agent to reduce aphid numbers. It's such a handsome, beneficial species that despite being an invasive it's been designated the official state insect of six different states -- Delaware, Massachusetts, New Hampshire, Ohio, Pennsylvania, and Tennessee.

The ladybugs' bright colors warn birds and other predators that ladybugs are bad to eat. Seven-spotted Ladybugs secrete toxic alkaloids -- N-oxide coccinelline and its free base precoccinelline -- from joints in their legs.

You might consider getting involved in the Lost Ladybug Project, designed to monitor the welfare of the various ladybug species, and particularly welcoming for younger participants. Despite my age, I thought the Project folks might appreciate my fairly decent picture documenting the species in a part of the country less studied than many others so I went to the Lost Ladybug site at http://www.lostladybug.org/, clicked on "upload photos," provided collection information such as exact latitude and longitude, and uploaded my picture. I was surprised a few days later when an email informed me that the ID had been confirmed, my information added to the Lost Ladybug databank, and that I could see my submission at http://lostladybug.org/contributors-images.php?id=2420.

If you visit that page not only can you see my picture but also links at the page's left take you to interesting maps and pictures that are extremely informative about which species are where, and how often they're seen. Our Seven-spotted Ladybug turns out to be very frequently documented all across the continent, including by several other spotters in Mississippi, so my observation is not a big deal. However, now I'm so sensitized to ladybugs and well informed about them that henceforward I intend to make special efforts to look for them, and continue contributing to the Lost Ladybug Project's database.

*****

FEMALE SOUTHERN HOUSE SPIDERS
A couple of Newsletters ago we looked at the male Southern House Spider who hangs in a cobweb in the storage room where I work. You can see that long-bodied, long-legged fellow at http://www.backyardnature.net/n/a/kukulcan.htm.

Since harmless Southern House Spiders are somewhat similar to poisonous Brown Recluse Spiders, this week I went looking for Recluses. In another storage building, knowing that Brown Recluses most commonly are found in dark, narrow spaces between and beneath things, I turned over a knee-tall, blue, plastic Coleman cooler, and found what's seen at http://www.backyardnature.net/n/12/120819sp.jpg.

The cottony ball above the spider is the egg bag she is guarding. Notice the juvenile spider below the big spider's abdomen. From leg tip to leg tip is about two inches (5cm). At first I thought I had a Brown Recluse, but the front part, the cephalothorax, lacked the distinct violin-shaped silhouette characteristic of that species. A close-up of this one's cephalothorax is shown at http://www.backyardnature.net/n/12/120819sq.jpg.

It took my heat-dazed mind awhile before it occurred to me that maybe this was a female Southern House Spider. When researching the male we'd learned that in this species females are much stubbier and have relatively shorter, thicker legs than males. On the Internet it was easy to see that this was the case. It's interesting to compare the slender male at the top of our Southern House Spider page with this much heavier female. This species demonstrates tremendous "sexual dimorphism."

*****

STILTS IN THE REFUGE'S PUMP-FLOODED FIELDS
Because of the drought upstream the Mississippi River is so low that in places barge traffic is impossible. Therefore I wasn't surprised this week when Karen and I visited St. Catherine Creek National Wildlife Refuge just south of Natchez and found that where during most of the year there are flooded fields and swamps, now there's dry land. However, many fields were indeed flooded, for the Refuge managers pump water into them specifically for wildlife. An article in the Natchez Democrat reports that in the Refuge about 200 acres (81has) are being flooded for birds.

Even now in August well before most migrating birds have begun arriving from the North certain water-loving species were using the flooded flats, such as the Black-necked Stilt stalking through shallow water at http://www.backyardnature.net/n/12/120819st.jpg.

Mostly we've seen Black-necked Stilts in Mexico, but here they're summer breeders, and some might overwinter here in mild winters. The species appears to be expanding its area of distribution. One wonders how birds like stilts are surviving this summer's extreme drought, which is occurring mostly in the Black-necked Stilt's breeding grounds in the western and south-central US. This year for many species the Refuge's artificially-flooded fields are truly refuges.

*****

JUVENILE WHITE IBISES
Also we've seen lots of White Ibises in Mexico, but they didn't look like the ones spotted this weekend in St. Catherine Creek National Wildlife Refuge's pump-flooded fields. Our Mexican White Ibises have been white. You can see the brown wings and brownish head but white rump of a juvenile White Ibis flushed from a flooded ditch at http://www.backyardnature.net/n/12/120819ic.jpg.

Another brown-winged juvenile foraging on a flooded field's spillway took to the air when we drew too near and landed nearby. You can see him next to a similarly spooked Snowy Egret at http://www.backyardnature.net/n/12/120819ib.jpg.

White Ibises breed in our area and might overwinter during mild winters.

*****

JUVENILE BLUE-WINGED TEALS
At http://www.backyardnature.net/n/12/120819tl.jpg you see a couple of ducks whose identity had me stumped until the male on the right positioned himself perfectly for sunlight to illuminate his blue wing patch bordered with a white stripe. The rest of his plumage doesn't match any I can find for the Blue-winged Teal, but with such a blue, white-bordered "speculum," what else could he be? Neither duck's bill is long enough to be a Shoveler.

Blue-winged Teals nest well to the north of here, only overwintering in this area, so these must be fresh arrivals. The species is known to undertake spring migration later than most ducks, and fall migration early, so their appearance here must qualify as an early arrival. After such a long, hot, humid summer, just seeing them evokes thoughts for more agreeable weather to come.

*****

A WHITE, YELLOW-LEGGED, LITTLE BLUE HERON
Now in mid August not only are juvenile birds with strange plumages showing up but also wandering adolescent birds are turning up in strange places. One morning this week I heard a squawking unusual for this wooded area and traced it to big, gawky, white bird perched atop the neighbor's martin box, as shown at http://www.backyardnature.net/n/12/120819he.jpg.

This is an immature Little Blue Heron, evidently freshly fledged because usually Little Blues in their white juvenile plumage display dark, slate-colored legs, not yellow ones. In the Refuge I saw some blotchy immature Little Blues, so-called Calico Herons, but they were too fast to get a picture of.

*****

LADY'S EARDROP VINE'S STRANGE FRUITS
Something fairly constant in the world of flowers and fruits is that the vast majority are symmetrical -- either radially symmetrical like acorns or bilaterally symmetrical like a maple or ash samara. Even with something like a pear with its top bulge veering off to one side, if you cut across its center perpendicularly to its axis, inside you'll find a radially symmetrical, star-shaped part where the seeds form. Therefore, in Nature unsymmetrical fruits catch your eye. The other day at the edge of a swamp in St. Catherine Creek National Wildlife Refuge just south of Natchez a soft-woody vine with grapevine-like tendrils was bearing hundreds of odd-shaped fruits, as shown at http://www.backyardnature.net/n/12/120819br.jpg.

A close-up of some curvy, 1¼-inch long (32mm) fruits is shown at http://www.backyardnature.net/n/12/120819bs.jpg.

Technically these fruits are achenes -- they're dry, one-seeded and don't split open upon maturity. Sunflower "seeds" are achene fruits.

The vine is variously called Lady's Eardrops, Eardrop Vine, Buckwheat Vine, and Red Vine. It's BRUNNICHIA OVATA, a member of the Buckwheat Family, the Polygonaceae, and it's mainly a Southeastern US species, inland found as far north as southern Illinois.

Studies list Lady's Eardrops' fruits as a "duck food," and surely other critters eat them, too.

*****

SMARTWEED
Speaking of members of the Buckwheat Family, when I was growing up on the bottomland farm in western Kentucky back in the 50s and 60s the most commonly encountered member of that family was the knee-high weed shown at http://www.backyardnature.net/n/12/120819pm.jpg.

That's the Pennsylvania Smartweed, PERSICARIA PENSYLVANICA, and my father hated it because in low parts of his soybean fields where water pooled after rains, sometimes he had more smartweed than soybeans. Smartweed grew rampantly in drainage ditches and along roadsides. With the advent of the scorched-earth herbicide use we have nowadays, you seldom see the smartweed oceans we sometimes had back then. Even then I admired their vigor, and with my magnifying glass I liked nosing into its little flowers, a close-up of which one is shown at http://www.backyardnature.net/n/12/120819pn.jpg.

One flower feature seen here typical of members of the Buckwheat Family is that the white, five-lobed flowers are not differentiated into the usual green calyx and colorful corolla. Rather there's a "perianth," which is what you call the colorful part when the calyx and corolla are merged into one thing. Inside the perianth six or so stamens surround a taller, divided style, the style branches terminating with globular stigmas, where pollen is supposed to germinate.

Maybe the easiest-to-see field mark of members of the Buckwheat Family, however, is a vegetative feature, which is unusual. The stems of most Buckwheat Family members are surrounded by very conspicuous stipules where leaves attach to the stems. You can see our Smartweed's stipule at http://www.backyardnature.net/n/12/120819po.jpg.

The online Flora of North America lists 26 Persicaria species for North America, and features of the stipule are very important in "keying out" the various species. The stipule of our Pennsylvania Smartweed is distinctive by being like a cylinder of brownish cellophane that bulges out somewhat at the base, and which at the top bears no fringe of hairs or slender spines. Without noticing these stipule features it can be hard to distinguish this species from closely related ones.

Once the flowers have set fruit you can rake the plant's spikelike inflorescence through your fingers and tiny, black, shiny, achene-type fruits will gather in the palm of your hand. Since this is the Buckwheat Family, I'll bet that if you had enough of these fruits you could grind them into a flavorful and nutritious meal, but they're so tiny that there'd be a lot of work for just a little meal. Birds, especially ducks, and other wildlife love them, though.

I read that indigenous Americans used tea made from the whole plant for diarrhea and made poultices from the leaves for piles.

Despite Pennsylvania Smartweed being so weedy, it's a native American plant occurring over most of forested North America except for western Canada and much of the northwestern US. It also extends through Mexico and Central America deep into South America.

When I was a kid I always wondered what was so smart about smartweed. Etymologists say that the name derives from the fact that smartweed juice on your skin causes it to smart -- to be irritated. However, I've never found smartweed juice to have any effect at all on my skin.

*****

WOOD SAGE AT WOODS EDGE
At weedy edges of bottomland and swamp woods nowadays a certain robust, waist high herb is issuing exotic-looking flowers. The blossoms are arranged in pale, spikelike racemes that show up vividly against the dark green woods. You can see a typical inflorescence arising from a leafy stem at http://www.backyardnature.net/n/12/120819tm.jpg.

A side view of one of its unusual flowers is shown at http://www.backyardnature.net/n/12/120819tn.jpg.

This wildflower is good to know because it's so widely distributed -- found throughout nearly all of forested North America, into Mexico and Cuba -- and it flowers appear during that super-green, in-between season when it's too late for spring wildflowers and too early for fall ones. Because this herb is so widely distributed it goes by several names, including Wood Sage, Germander, Canada Germander, American Germander, Hairy Germander, and Wild Basil. It's TEUCRIUM CANADENSE, and if you know your herbs and wildflowers you'll have recognized from the plant's flower anatomy, its tooth-margined (serrated), opposite leaves and its squared stems that Wood Sage is a member of the Mint Family, the Lamiaceae.

The flowers are adapted to pollination by long-tongued bees, including bumblebees, honeybees, as well as by bee flies, thick-headed flies, and various butterflies or skippers.

Wood Sage reminds us that all mint species don't necessarily produce "minty-smelling" herbage. Wood Sage's leaves smell mildly foul, with no hint of mintiness.

Web pages dealing with medicinal plants copy from one another the mind-numbing sentence "A tea made from the leaves is diaphoretic, diuretic and emmenagogue," but in general nowadays Wood Sage isn't regarded as being particularly medicinal. It's just nice to see, and it makes pollinators happy, and their predators.

*****

HOODED ARROWHEADS AT THE WATER'S EDGE
Along the muddy banks of Butler's Lake in St. Catherine Creek National Wildlife Refuge just south of Natchez a handsome aquatic plant with large, glossy, arrowhead-shaped leaves atop long, slender, succulent petioles form a pretty fringe, punctuated here and there with small clusters of inch-wide (2.5cm), white flowers hiding among shadows below the leaves, as shown at http://www.backyardnature.net/n/12/120819sg.jpg.

Anyone who hangs around wetlands soon learns that these water-loving plants can be called Arrowheads. They're monocots, like lilies, orchids and grasses, and belong to the Water-plantain or Arrowhead Family, the Alismataceae, and the Arrowhead genus, Sagittaria. I assumed that these plants were the Broadleaf Arrowhead, Sagittaria latifolia, commonly found throughout eastern North America south to northern South America. However, about 24 Arrowhead species are treated in the online Flora of North America, so I figured I'd better confirm my assumption, and it's a good thing I did.

The above picture shows some important field marks I hadn't noticed while at Butler Lake. For example, in the photograph's lower, left corner, notice that on the thick flower-cluster stem, or peduncle, immature fruits are forming on similarly thick flower stems, or pedicles, and that the pedicels are shorter than the pedicles of the flowers above them, and strongly curved downward. Also, the green sepals below the developing fruiting heads wrap around the future fruits, instead of flaring outward or turning backwards. A close-up of some flowers shows another distinctive feature, at http://www.backyardnature.net/n/12/120819sh.jpg.

Namely, the three petals, instead of being completely white as in most Arrowhead species, are conspicuously blotched below with yellow-green.

So, this isn't the Broadleaf Arrowhead, but rather one often called the Hooded Arrowhead. Experts are about evenly divided as to whether it's a variety of Sagittaria montevidensis, in which case its name is SAGITTARIA MONTEVIDENSIS var. CALYCINA, or whether it's a full species, Sagittaria calycina. The Flora of North America goes with the former, so that's how we'll list it here. The variety calycina is described as occupying mud flats of lakes and rivers in much of the central US, from West Virginia to Colorado, and southern Minnesota into Louisiana and eastern Texas, with outlying populations here and there, especially in California and Mexico. The broader species, montevidensis, differs in having dark purple spots at the petal bases, instead of yellow-green ones, and is a native of South America, but has been introduced in many places.

This and other Arrowhead species produce peanut-sized, starchy tubers relished by ducks and other wildlife, as well as indigenous Americans in former times. Other names for Arrowheads in general are Duck Potato and Indian Potato. In our first picture you may have noticed that many entire leaves had been stripped from their petioles. Beavers and muskrats are known to eat Arrowhead leaves so probably that's what happened here. Leaf removal had been almost total over a large area. The leaves in our photograph appear to be smaller ones emerging after the removal of the first blades.

So, this is an important, worthy species and on that hot morning in the Refuge it was good seeing it thriving and contributing to the broader community so lustily there at the water's edge.

*****

FLUORITE ON GRAVEL
When I returned to the car Karen had collected several pieces of limestone gravel that had been trucked in to cover the road. What had caught Karen's eye is that some of the faces of these rock particles displayed a distinct violet hue, as shown at http://www.backyardnature.net/n/12/120819ft.jpg.

Karen had collected similarly colored amethyst in a mine in Arkansas so she was excited and full of questions, knowing that amethyst is a valued gemstone and that where there's a little amethyst there might be more.

"Fluorite," I said, which Karen didn't find very convincing. That particular violet hue is rare among rocks, and she'd only seen amethyst of that color.

The definitive way to distinguish the two minerals is by noting the form of their crystals. Amethyst is a form of quartz, so its crystals are normally six-sided prisms. In contrast, fluorite crystals normally are cubic, with four sides. However, the violet mineral on this limestone gravel wasn't forming crystals large enough to see without a microscope, so that evidence wasn't available to us.

My ground for calling it fluorite and not amethyst was that the violet color appeared on the face of a piece of limestone gravel. Limestone is mainly calcium carbonate (CaCO4), and fluorite is calcium fluoride (CaF2). Both are based on calcium, and fluorite is known to occur in mineral veins in association with limestone.

In contrast, amethyst, being a form of quartz, is silicon dioxide (SiO2), based on silicon. Though quartz is abundant in most forms of sand and as an "impurity" in sedimentary rocks like limestone, it originates in igneous and metamorphic environments. The limestone from which our gravel was made was a sedimentary rock, not an igneous or metamorphic one. Karen had seen her amethyst in a quartz-crystal-collecting mine up in northwestern Arkansas, amethyst was to be expected there, but not here.

But, it's interesting enough to find fluorite, for that mineral can be very pretty and useful. Sometime it forms spectacular crystals worthy of exhibition in museums, and sometimes it's used decoratively. It's also much used in industry, where it is referred to as fluorspar.

Because of fluorspar's low melting temperature, traditionally it's been used as a flux. In the field of metallurgy, fluxes are substances employed to refine metals by combining with impurities to form a molten mixture that can be readily removed. So, in the production of aluminum, for instance, fluorspar is added to ore, it combines with the non-aluminum part, then you remove the fluorspar "slag" that separates from the aluminum, and are left with a more refined aluminum. Purer forms of fluorspar are used to manufacture opalescent glass, enamels and cooking utensils. The highest grade of fluorspar is used to make hydrogen fluoride and hydrofluoric acid, both much used by the pharmaceutical and other industries. For example, hydrogen fluoride serves as a catalyst during the oil refining process.

*****

FREE, WELL ILLUSTRATED, ONLINE, INTERACTIVE IDENTIFICATION KEYS
Lately at http://www.discoverlife.org/mp/20q the DiscoverLife.Org website has made available a wide selection of well illustrated, interactive identification keys to a wonderful hodgepodge of plants and animals. There are keys to the wildflowers, trees, snakes and salamanders of North America, as well as the frogs and toads of Panama, the land snails of Jamaica, and many other groups.

My own webpage at http://www.backyardnature.net/i-ident.htm also has become fairly popular because it provides many other links to online pages helping with identification -- from the very technical and enormous "Flora of North America" to the "Common Ticks of Illinois" and "Common Wildlife Scat Found around the Home."

*****

FEATURED ESSAYS FROM THE PAST:

"A Perfect Black-Necked Stilt," from the April 14, 2007 Newsletter, at http://www.backyardnature.net/n/p/070414.htm.

"Nature Jazz," from the January 3, 2010 Newsletter, at http://www.backyardnature.net/n/p/100103.htm.

*****

Best wishes to all Newsletter readers,

Jim