from the woods near Natchez, Mississippi, USA
July 25, 2004
ON THE CHARM OF PREDACEOUS DIVING BEETLES
I think most of us are wired to be "charmed" by certain things, at least when we're children and our minds are still open. The term "charmed" is too weak for the state of mind I'm describing, but I don't think English has any better word. I'm referring to a feeling akin to "love at first sight," except that it's a fixation on something besides another person. It amounts to an inexplicable, perfectly irrational, passionate fascination for something.
I've always thought that "being charmed" by something was the Creator's manner of nudging our lives toward certain paths leading to fulfillment. For example, as a child I was charmed by many things, especially trees and turtles, so here I am still talking about trees and turtles. One of my lesser charmings focused on Predaceous Diving Beetles.
On the farm in Kentucky we kept large, wooden barrels beneath the eaves of one of our sheds for collecting water for laundry and bathing. Predaceous Diving Beetles took up residence in the barrels and I spent hundreds if not thousands of hours with my head over the barrels' rims looking down at them. They were about 3/16-inch long (5 mm), oval shaped and brownish with a black band at the rear end (the brownishness revealed itself as golden flecks in bright sunlight). You can see what may be the very species I'm remembering by clicking here.
About all my beetles did was to paddle about within the barrels' water looking for tiny critters to eat, often coming to the water's surface to take air into their rear ends, thus spending a lot of time upside down at the water's surface. What transfixed me was the beetles' ability to explore at will their three- dimensional, sunlight-charged world, alternately spiraling like vultures in the air, then diving deeply through clear water charged with sunlight that exploded inside tiny, free-floating algal cells. The beetles were like spaceships wandering among stars. Their liberty and scintillating milieu contrasted so exquisitely with the life of farm-kid me stuck in a very fat body anchored in an obscure corner of rural Kentucky.
I've been thinking about those days lately because the barn-eave bathtub here in which I soak for a moment during the hottest part of each day has a nice population of Predaceous Diving Beetles. If you change the tub's water, the beetles will be back the next day. Mainly they feed on flying ants that descend in the wrong place.
By "Predaceous Diving Beetle" I mean one of many species belonging to the Predaceous Diving Beetle Family, the Dytiscidae. There's actually a second species in my tub, a larger, black one who bites my skin as I soak, but I've never been "charmed" by that one.
FIRE ANTS & WANDERING GLIDERS
Speaking of insects capturing my imagination, this week at the edge of a field I came upon a gathering of dragonflies -- between 50 and 70 medium-size (body length 1.9 inch, 4.8cm, long), yellowish individuals all of the same species, forming a very animated, diffuse cloud about the size of a normal bedroom. The cloud's epicenter lay over a fire-ant mound from which hundreds of fire ants were emerging, about a third of them being winged. As the winged ants fluttered into the air they were snatched by the dragonflies. I doubt that a single fire ant survived its flight and for that I am grateful to the dragonflies.
For about 15 minutes I stood there trying to identify the dragonflies with the "Dragonflies through Binoculars" book Jerry Litton gave me, but the creatures simply flew so fast back and forth above the fire ant mound that I couldn't see the details needed. I concentrated so hard on the darting insects that I got motion sick and had to go sit down.
In about an hour I returned and this time a couple of dragonflies were resting on bluestem stems and now I could see that they were Wandering Gliders, PANTALA FLAVESCENS. And what a surprise when I read that "It is the only dragonfly found around the world, breeding on every continent except Europe." The book also considers it "The world's most evolved dragonfly" because of its exceptional ability to travel long distances, including over oceans where they may fly day and night for thousands of miles. The species is known to feed in swarms, just as I was seeing, but the more normal fare being small insects stirred up by large animals. There's a fine page on this species at www.esb.utexas.edu/jcabbott/odonata/bfl/bflspecies.asp?TaxaID=311
The part about this species that sets me daydreaming is the book's remark that the species "drifts with the wind as it feeds on aerial plankton until an air mass of different temperature produces the rain pools in which it breeds."
Imagine -- floating for days high in the air, feeding on plankton suspended there, so attuned to air pressure and humidity that you know when temporary pools are forming below you. And it's true that I found this swarm about an hour after a nice shower. These dragonflies seem to dance through the sky like my Predaceous Diving Beetles dance through clear water.
One of my favorite books is a German one, "Die unendliche Geschichte," or "The Unending Story" by Michael Ende. In the book, the hero Atréju rides about the world on a "Glücksdrache," a "lucky-dragon," which is "a creature of air and warmth, a creature of unbounded happiness, and despite its enormous size, as light as a summer cloud."
These Wandering Gliders sailing in clouds of wing- glisten, so sensitive to currents of air, and tending to visit Earth mainly at that magical moment right as the sun comes out after a summer rain, are the closest thing I've ever seen to a real Glücksdrache.
COMMON CHECKERED SKIPPERS
The other day on a slender, flowering spike of purple vervain I spotted a small butterfly warming its wings against the rising sun. It was especially pretty, the wings being dark brown but heavily "checkered" with small, white spots artfully arranged in broad bands, the wings neatly fringed in white. It was the Common Checkered Skipper, PYRGUS COMMUNIS, shown at http://wisconsinbutterflies.org/species/220
When I spot a plant or animal that in any way strikes me as other than a daily visitor, I always pay special attention. I'd seen butterflies similar to this one, but you just never know when something rare and noteworthy might appear. Therefore, immediately upon spotting the skipper I got my Audubon Field Guide and confirmed its identification. Several rarer, look- alike species do exist, such as the Tropical Checkered Skipper and the Small Checkered Skipper, but this time I just had the Common.
Still, the exercise gave me a chance to read more about this more common neighbor. The book says that its caterpillars eat leaves of the Mallow, or Hibiscus, Family, so maybe now I know who ravaged my hibiscuses this spring!
I hope you don't forget the fun you can have using field guides to identify things, to find rare occurrences, and to get new insights into organisms you thought you already knew all about. Field guides open all kinds of doors. Also don't forget my web pages describing field guides and telling how to use them, and where to get them, at www.backyardnature.net/fd_guide.htm
FLOWERING CRABGRASS The other day I was happy to find a flowering specimen of Crabgrass, DIGITARIA SANGUINALIS, in the garden. In many towns and suburbs Crabgrass may be the most commonly encountered wild-growing grass, but here it can't compete with other weeds. Crabgrass is to the plant world what House Sparrows are to the bird world -- they require someone to be constantly degrading the local ecology just to survive. Like House Sparrows, Crabgrass is a species introduced from Europe.
This was the first Crabgrass I'd found out here, and that enabled me to prepare a Crabgrass Flower Structure Page for my nature website. Crabgrass flowers themselves are less interesting than how the flowers are arranged in their flower cluster. The cluster is composed of several spike-like racemes arising from the very top of a stem, the "peduncle," the way fingers arise from the palm of hand. In fact, since fingers are "digits," that accounts Crabgrass's genus name -- Digitaria.
My new Crabgrass-flower-structure page is at www.backyardnature.net/fl_crabg.htm
BOOKS FOR THE SEASHORE
Leslie in Alabama is homeschooling her kids and wrote asking me if I know of a nature site like mine focusing on the seashore. She needed help teaching about seashore plants and animals during an upcoming fieldtrip to the beach.
I didn't know of such a site, but I suggested that she use the approach outlined on my "3 Steps to Knowing Nature" page at www.backyardnature.net/listopen.htm. First identify plants and animals, then "look up the names" and, finally, continue gathering information around those names for the rest of your life.
To further help Leslie and others wanting to know more about seashore life I've added a couple of new pages providing book titles dealing with the identification and interpretation of seashore biota. On these pages you can review the books and order them from Amazon.com if you want. To access the pages go to www.backyardnature.net/amazon/index.htm and click on Option #6, "At the Beach."
MORE ON HOT HUMAN BODIES
I had thought that last week's remarks on Homosexuality in Nature would bring the most comments from subscribers, but more words bounced back about keeping cool than anything else. Maybe it's just too hot these days to think about society's big questions. What people really want to focus on is keeping cool.
Leon up at Vicksburg recalled that back in his wandering days out West he often saw native Americans "sitting out in the hot desert selling rugs and jewelry -- I believe they were Navajos -- sometimes under a tent, but not always. They were wrapped in layers of what looked like wool blankets to me!" He also noted that Lawrence of Arabia and his cohorts were wrapped from head to toe, not naked.
I suspect that if the hot air around Leon's Navajos and Arabians had been as humid as it is in southern Mississippi, soon they would have become disciples of nakedness, too. If you think about all the National Geographic shows you've seen on traditional cultures in humid tropical areas, I'll bet you recall seeing more nakedness than covering up.
However, I have been in villages of the Lacandon people in lowland southern Mexico, and they wore not only long hair but also white, tunic-like coverings reaching to their knees, so maybe sometimes even in hot, humid areas covering yourself can be a reasonable option.
I've been in very hot, humid parts of Argentina where during the hottest part of the afternoon people habitually sipped cups of steaming-hot Yerba Maté (from leaves of a kind of holly) and my hosts offered me hot English tea, the theory being that the resulting sweating and "something in the tea" cooled you off.
Hillary on the Gulf Coast found some great websites for those of us with nerdy tendencies. One of them touches on such things as how the Laws of Thermodynamics apply to the cooling of human bodies, and knowing that, for example, at 73°F (23°C) the average inactive adult male loses heat at a rate of about 90 watts purely as a result of his basal metabolism. This site is at http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/coobod.html#c1
Another site focuses on mathematically quantifying heat-loss, and there's a fine graph showing how body- heat considerations change depending upon whether you are naked or clothed. This Hong Kong site is at http://personal.cityu.edu.hk/~bsapplec/heat.htm
After I jog each morning I hose myself off but I keep sweating as I prepare breakfast at my campfire, as indicated by the honeybees who settle on my back, arms and legs as I work. I just ignore them and try to avoid annoying them. But Wednesday one got between my legs and when I took a step a bee thought she was under attack and I got stung.
When a honeybee stings you the first thing you should do is to see if the singer has come off, for, if it has, the poison sac will remain atop the stinger pumping poison into your skin long after the bee has gone. Remove the stinger as fast as possible. You can see a much magnified picture of a detached honeybee stinger with the poison gland atop it still pumping away at www.beeremoval.net/About_Bees/HB_stinger.JPG
A sad thing about the bee losing its stinger is that the bee then dies within a few hours. By stinging you, the bee is committing suicide. Therefore, from the bee's point of view, the question of whether the stinging must take place is a critical one. Stinging is not done lightly.
A lot of thinking has been done about how bees could have evolved so that individuals are programmed to give up their lives for the community's sake. To understand the answer you have to think in terms of the bee community's genetic heritage being carried by the queen, not the workers. In this light, we are almost struck with a sense of injustice when we see how expendable the workers' lives are. There's nothing democratic or even-handed here. The workers are created simply to work for the community, to sting when there's a need, and then to die.
Some serious thinkers have proposed that among such socialized insects as bees, the "individual" should be better thought of as the diffuse community of bees, not the individual bees we see at our flowers. In this concept the queen is seen as being like a gland secreting hormones and the workers are like corpuscles in the human circulatory system roaming about doing whatever the queen's hormones dictate. Is there really a rule in nature that a body has to be in one place -- that hormones must be transported in veins instead of on wings and six legs? We have examples of distinct species merging to form completely new life forms (fungi and algae merging to form lichens), so why can't the opposite be true, one thing manifesting itself as a community?
For me these insights are important to consider because part of the bedrock of my belief system is that I regard human beings as being no more than highly specialized mammals. In doing so I'm not at all belittling humans, but rather regarding other animals as much more complex, self-aware and beautiful than most people admit. Therefore, if what's spiritually important in me is my "sense of identity," my "consciousness," or my "soul," in the diffuse bee- individual to whom I with great pride claim biological relationship, just where is the "sense of identity," the "consciousness," or "the soul?"
Already it's known that consciousness or sense-of- identity doesn't reside in any particular cell or group of cells, or nerve or organ. Even people who lose half of their brain continue thinking and functioning as regular humans, perhaps showing only a certain "flatness" in their personalities. This thing we think of as our consciousness -- our selves -- appears to just happen, maybe as a natural consequence of being embedded inside a lot of complex electrochemical circuitry. If that's the case with bees, then how pretty it is to think of the bee soul as being focused in the hive, but diffusing outward into communities of flowers in the fields.
Of course once you start thinking in this direction, then you come face to face with Gaia -- the Earth- Ecosystem-self-awareness-complex. In other words, maybe the Earth does feel, and react, like a single living organism. Certainly a lot of what happens appears to support that idea. For example, ecosystem- destroying humans on an overpopulated Earth are analogous to germs infecting a human body. As the human body reacts to disease by producing antibodies to control the germ population, Gaia's body does the same thing as diseases, famines and wars appear among us humans.
And, beyond Gaia, the Universal self-aware complex...
So, this was the train of thought blossoming from my bee-sting. How wonderful to be a thinking human animal.
There's a fine site explaining what the Gaia Hypothesis is all about at www.oceansonline.com/gaiaho.htm