Dragonflies, Humility, and the Conservation of Biodiversity

A female Widow Skimmer (Libellula luctuosa).  Copyright: Richard Telford, 2014

A female Widow Skimmer (Libellula luctuosa). Copyright: Richard Telford, 2014

By:  Richard Telford

In 1970, Roger Tory Peterson wrote, “Entomologists fall into two categories:  those who find insects endlessly fascinating and those who would get rid of them.”  Reflecting the controversy at that time over the indiscriminate use of DDT (for which the U.S. Environmental Protection Agency would subsequently issue a cancellation order in 1972) and other pesticides, Peterson suggested that the latter group of entomologists might “eventually wind up working for chemical companies, devising more sophisticated techniques of annihilation.”   The dualism that Peterson notes above, though necessarily oversimplified, is nonetheless reflective of a pattern that extends far beyond the world of entomologists.  Insects have a remarkable capacity to evoke in their human observers both fear (largely irrational and unfounded) and wonder (quite rational and well founded).  In his ground-breaking books on the insect world, Grassroot Jungles (1937) and Near Horizons (1942), Edwin Way Teale extolled the immeasurable value of the latter response; it required, he argued, only the willingness to slow the pace of our hectic lives long enough to observe a complex and remarkable world we largely overlook.

A female Eastern Pondhawk (Erythemis simplicicollis), perched on the author's son's tricycle handlebar, consumes an insect taken on the wing.  Note a discarded appendage in the  Copyright 2014, Richard Telford

A female Eastern Pondhawk (Erythemis simplicicollis), perched on the author’s son’s tricycle handlebar, consumes an insect taken on the wing. Note a discarded appendage in the foreground. Copyright: Richard Telford, 2014

Few insects offer a more ready source of wonder than dragonflies, which are grouped with damselflies in the order Odonata.  The name Odonata is derived from the Greek odonto, meaning tooth—a reflection of their powerful, sharp-toothed mandibles and maxillae, the paired upper and lower jaws that facilitate quick, efficient consumption of prey.  Dragonflies, which form the suborder Anisoptera, take prey only in flight, often cupping their six barbed legs in a basket-like shape in order to entrap their target; smaller prey is often consumed without landing.  The maxillae contain a pronged inner piece that James G. Needham described in his classic 1929 A Manual of the Dragonflies of North America as “perfectly shaped for a meat fork, used for holding a captured insect and for turning it as the mandibles cut it up.”  The deftness of this process is readily apparent when observing a perched dragonfly speedily consume its prey.  This is just one of a host of evolutionary adaptions that have shaped the dragonfly into the unrivaled aerial predator of the insect world.

A top view of a female Widow Skimmer(Libellula luctuosa). The complex venation of dragonfly wings  can create up to 3,000 isolated "cells" in the membrane of each individual wing,  Copyright: Richard Telford, 2014

A top view of a female Widow Skimmer(Libellula luctuosa). The complex venation of dragonfly wings can create up to 3,000 isolated “cells” in the membrane of each individual wing. Copyright: Richard Telford, 2014

Dragonflies possess four wings, each of which can move independently of the others and can rotate on a forward and backward axis, yielding a supremely dynamic capacity for flight.  Dragonflies can fly in all geometric planes.  Helicopter-like, they can fly straight up and down or hover in place.  They can fly backward and forward, turn abruptly at acute angles, and repeatedly flip their bodies.  Harvard Biochemist Stacey Combes, leading a team of researchers who have studied dragonfly flight in a specially built enclosure at the Combes Laboratory in Bedford, Massachusetts, has noted that dragonflies can perform hundreds of such flips while hunting, seemingly without significant exertion.  Her team has also documented predation success rates as high as 90 percent in some dragonflies—a truly astonishing figure.  Equally astonishing is the speed with which dragonflies engage in these aerial acrobatics.  Dragonflies routinely fly at speeds of 15 to 30 miles per hour, with some species flying considerably faster.  Credible speed estimates for the Green Darner (Anax junius), for example, range between 35 and 55 miles per hour during straightaway flight.  This prompted Edwin Way Teale, in Grassroots Jungle, to title his dragonfly chapter “Winged Bullets.”

A close-up view of the compound eyes of a female Blue Dasher (Pachydiplax longipennis).  The ommatidia, or individual lenses,  are plainly visible.  Copyright: Richard Telford, 2014

A close-up view of the compound eyes of a female Blue Dasher (Pachydiplax longipennis). The ommatidia, or individual lenses, are plainly visible. Copyright: Richard Telford, 2014

One other adaption deserving special note is the dragonfly’s pair of bulbous compound eyes, each of which can contain up to 30,000 ommatidia, or individual lenses, each with its own cornea.  The extraordinary perceptive sensitivity of such a structure, in conjunction with the size and placement of the dragonfly’s compound eyes, yields a nearly 360-degree field of vision—a critical adaption that facilitates the flight patterns and the predation success rate outlined above.  The dragonfly’s acuity of sight likewise provides a critical defense against predation.  Furthermore, while the human eye contains three opsins, or light-sensing proteins, dragonfly eyes can possess up to five.  So, while we effectively perceive color through the RGB scale (Red, Blue, Green,) dragonflies can additionally perceive ultraviolet light invisible to humans as well as plane-polarized, or reflected, light.  This latter capacity is clearly valuable to a creature that begins its life in water and is destined to return there; both the female and the male return to the water, the former to lay eggs and the latter to protect her during that vulnerable process.

A female Common Whitetail Skimmer (Plathemis lydia) at the day's end.  Unless disturbed, it will remain there until the warmth of the following day revives it.  Copyright: Richard Telford, 2014

A female Common Whitetail (Plathemis lydia) at rest behind the author’s compost pile at the day’s end. Unless disturbed, it will remain there until the warmth of the following day revives it. Copyright: Richard Telford, 2014

Early this summer, toward dusk, I walked out to the compost pile located at the edge of our yard.  Just behind the compost pile, in an overgrown former strawberry garden, I spied a dragonfly suspended by its six legs, wings spread, where it would sleep for the night.  Prior to reading Edwin Way Teale’s Journey Into Summer (1960), I had never thought about the sleep of insects.  In his book, Teale on a number of occasions notes finding insects at rest at twilight or by flashlight during the night.  Teale’s observations of this phenomenon, which had persisted in my mind only in abstract form, took shape before my eyes.  The natural world reminds us that there is so much to learn, or at the least so much to which we can pay attention if we choose to do so.  I stood long at our compost pile, swarmed by mosquitoes and mesmerized by the beautiful symmetry of this extraordinary creature, which I would later identify as a female Common Whitetail (Plathemis lydia); its stillness at rest contrasted sharply with its swift, deliberate, predatory daytime flight.  I hastily fetched a camera and tripod and, with long exposure times, took several photographs.

A female Eastern Pondhawk (Erythemis simplicicollis) perched in a group of bearded irises.  Copyright:  Richard Telford, 2014

A female Eastern Pondhawk (Erythemis simplicicollis) perched in a group of bearded irises. Copyright: Richard Telford, 2014

From that moment, influenced in part by recent time spent reading the correspondence between Rachel Carson and Edwin Way Teale housed at the University of Connecticut’s Dodd Research Center, and in part simply by a sense of wonder and appreciation, I have spent the summer photographing the dragonflies that hunt the cleared half acre of our old farm property.  All of the photographs that accompany this writing are the product of that effort.  As I do summer chores and projects, I keep near at hand a tripod-mounted camera with macro lens affixed.  While I sense that I have seen a greater variety of dragonfly species this summer than I can recall seeing during any of the previous ten summers spent in our 1770 farmhouse, I suspect this is not true.  Instead, this perception may simply result from, in Teale’s words, my choice to “pause like [a] stooping giant to peer down into the grassroot jungle at [my] feet.”

This female Widow Skimmer(Libellula luctuosa) repeatedly return to this perch during a long sequence of hunting flights.  Copyright: Richard Telford, 2014

This female Widow Skimmer(Libellula luctuosa) repeatedly returned to this perch during a long sequence of hunting flights. Copyright: Richard Telford, 2014

Recently, our local state roads have been lined with advertising signs for a regional Mosquito Squad franchise.  The signs promise, “No Bugs. No Bites. No Kidding.”  It is an unfortunate echo of Roger Tory Peterson’s statement above.  Several years ago, Lynne Peeples, writing for the Huffington Post, reported on mounting criticism that Mosquito Squad’s marketing use of a superhero-like cartoon character, Dread Skeeter, targets children and obfuscates both the human health and environmental risks inherent in spraying neurotoxic chemicals for insect control.  At a time when pollinating insect populations are suffering catastrophic declines, so much so that the White House just today issued a press release outlining the problem and proposing a course of mitigating actions, we must rethink our relationship with the insect world.  A world with no bugs and no bites is likewise a world with no biodiversity, and that is a world in which even the human species cannot survive.  In 1937, Edwin Way Teale wrote, “We cannot ignore the insects; we cannot dismiss them as insignificant.”  In 1970, Roger Tory Peterson wrote, “[…] insects, because of their astronomical numbers, are undeniably important in our lives.  They cannot be ignored.”  Still, more than 50 years after the publication of Rachel Carson’s Silent Spring, we struggle to accept the notion that our co-existence with the rest of the natural world cannot be negotiated on our terms alone.  Where Dread Skeeter succeeds, dragonflies, which rely principally on mosquitos and small gnats for survival, will vanish, and each loss of this kind precipitates a cascade of other such losses—another lesson that we have been slow to learn.

A female Blue Dasher (Pachydiplax longipennis) in the obelisk position.  Some dragonflies assume this position to reduce the percentage of body surface area that is exposed to the sun, effectively cooling them.  Copyright: Richard Telford, 2014

A female Blue Dasher (Pachydiplax longipennis) in the obelisk position. Some dragonflies assume this position to reduce the percentage of body surface area that is exposed to the sun, effectively cooling them. Copyright: Richard Telford, 2014

Recent research on dragonflies has revealed an extraordinary dimension to their hunting.  Rather than pursuing its prey, a dragonfly intercepts it, meaning that it must calculate the distance, speed, and direction of its target, adjusting its own speed and direction accordingly.  In this context, the predatory success rates of dragonflies documented at the Combes Laboratory are even more impressive. While its superb capacities for flight and vision certainly facilitate this action, it is a complex set of neurological functions that makes such sophisticated targeting possible.  This complexity, much of which we do not yet fully understand, should give us pause.  According to the fossil record, dragonflies have existed for nearly 300 million years, a fact which can perhaps begin to give us insight on this complexity.  Teale argued in 1937 that humans have “lived on earth but a single hour in comparison to the long history of the insects.”  The implicit humility of this statement is critical to the long-term preservation of the insect world and of biodiversity itself.

A male Blue Dasher (Pachydiplax longipennis).  Copyright:  Richard Telford, 2014

A male Blue Dasher (Pachydiplax longipennis). Copyright: Richard Telford, 2014

 

Exploring the Near at Hand

An Arrow-shaped Micrathena spider (Micrathena sagittata) backlit in a web it wove between two of our front porch columns.  Copyright Richard Telford, 2012

An Arrow-shaped Micrathena spider (Micrathena sagittata) backlit in late day sun in a web spanning two front porch columns of the author’s home. Copyright Richard Telford, 2012

By:  Richard Telford

Living in Baldwin, New York on western Long Island in 1936, American naturalist writer Edwin Way Teale lacked wilderness.  At least, to the casual observer it might seem so.  Teale, however, was not the casual observer.  He had for several months searched for a site with sufficiently varied habitat to support the widest possible variety of insect life, finally chancing upon an abandoned apple orchard just fifteen minutes from his home.  As he later noted in his 1942 book Near Horizons, the site included “a line of slender cedars, a weedlot, […] interlacing row[s] of apple trees, [… a] margin of solid ground along the swampedge, […and] a spur of land [that] juts out into the brown water of the swamp stream where slope and swamp meet at […] a great mound of wild-cherry trees [that] lifts its green bulk above the level of the cattails.”

Walking in the footsteps of French entomologist Jean Henri Fabre, whom he admired deeply, Teale rented the old orchard for ten dollars annually and, as Fabre had done at the Harmas de Sérignan in Provence, France beginning in 1879, worked deliberately to convert the site into an insect garden that would provide “the habitat of nearly every kind of insect found in the region.”  In this insect garden, Teale conducted intensive observations for six years while, for most of that time, maintaining his day job as a staff writer and photographer for Popular Science magazine, a job he came to loathe due both to the sense of confinement it imposed upon him and to the capriciously brutal politics of the magazine editorial room.  For Teale, the insect garden was not just a place for observation but a place for escape from the modern world’s “well-grooved path remote from the Enchanted Ponds and Mad Rivers of the open world.”

An Eastern Forktail damselfly photographed in the author's backyard.  Copyright Richard Telford, 2013

An Eastern Forktail damselfly (Ischnura ramburii) photographed in the author’s backyard. Copyright Richard Telford, 2013

In 1937, Teale published Grassroot Jungles, a book that compiled 130 macro photographs of insects, taken mostly at his insect garden, with accompanying text that expounded the life history of many featured specimens.  Teale’s photography was astounding for its day, and the book was featured in a full front-page review in The New York Times Book Review on December 19, 1937.  Reviewer Anita Moffett wrote, “Mr. Teale is well known for his insect photography, and these pictures combine fact with imaginative power in depicting the beauty and goblinlike [sic] grotesqueness of the fascinating and almost unknown world to which the reader is introduced.”  She noted that Teale’s book demonstrated that the study of insects could “be pursued in one’s own backyard as well as at the ends of the earth.”  Here, Moffett simply echoed Teale’s premise in Grassroot Jungles that “At our feet, often unnoticed in the rush of daily events, is the wonder world of insects,” the exploration of which “is a back-yard hobby open to all, […which] can begin a few feet from your own doorstep.”

The egalitarian quality of backyard nature study was not a trivial consideration in 1937 America, still largely in the economic throes of the Great Depression and four years away from a war-driven recovery.  Though the economic landscape has largely changed, the openness to all of backyard nature study is no less significant for a host of reasons that extend far beyond simple economics.  In fact, Teale’s premise is arguably more salient in the present age of widespread habitat fragmentation, rapid development, increasing privatization of large wilderness parcels, the alarming disconnection of so many children from the natural world, and a social media-blitzed society that makes Teale’s “rush of daily events” seem pastoral by comparison.

A male American Goldfinch (Carduelis tristis) eating petals of Daisy Fleabane (Erigeron annuus) less than ten feet from the author's back door.  Copyright Richard Telford, 2012.

A male American Goldfinch (Carduelis tristis) eating petals of Daisy Fleabane (Erigeron annuus) less than ten feet from the author’s back door. Copyright Richard Telford, 2012.

In a time when we feel increasingly disconnected not just from the natural world but from ourselves, it is perhaps more important than ever that we “pause like stooping giants to peer down into the grassroot jungle at our feet,” that we re-attune ourselves to the magnificent complexities of the natural world that go largely overlooked in the jumble of our daily lives.

Teale consciously manipulated the environment of his insect garden to maximize habitat, and thus the site’s inhabitant variety.  His manipulations included “an ageing pie-tin holding dabs of honey and syrup to provide a treacle-trough for ants and flies and wild bees” and “bits of decaying meat to bring carrion beetles from afar.”  However, such manipulations are not necessary for the back-yard naturalist.  The fecundity of the insect world, to our senses, seems to know no bounds, even in the smallest of natural landscapes.  Consider the fruit fly explosion that occurs when fruit is left a few days too long on the kitchen countertop.  It is perhaps a dangerous byproduct of that fecundity that we largely overlook the reality that many insects presently face potential extinction.  As of this writing, the Connecticut Department of Energy and Environmental Protection, for example, lists nearly 150 insect species as endangered, threatened, or of special concern.  Still, there are abundant insects to be seen on nearly any plot, even the most encroached upon or inhospitable.  This fact was illustrated for me this past summer during a trip to the local building supply store.

Exiting with a cart full of lumber, an odd green shape on the brick-facing of the store caught my attention, a large female praying mantis vertically perched with at least 200 yards of asphalt separating her from any floral retreat.  I went to my car, emptied my lunch cooler, and, as nonchalantly as possible, trapped her, self-conscious of the piqued curiosity of several passersby.  I recalled the story of Edwin Way Teale’s domesticated praying mantis Dinah, whom he brought to the Brooklyn Entomological Society and, during a side trip to the New York Public Library, lost and eventually recovered on Broadway, near Times Square.  While I was tempted to drive the displaced mantis home to unleash her predatory powers in our garden, I worried about her survival of the trip and instead drove her to the far end of the parking lot where a long strip of dense thicket masked a long stretch of highway on the hillside above.

A Twelve-Spotted Skimmer dragonfly (Libellula pulchella)landing in the author's default insect garden.  Copyright Richard Telford, 2012.

A Twelve-Spotted Skimmer dragonfly (Libellula pulchella)landing in the author’s default insect garden. Copyright Richard Telford, 2012.

The previous summer, largely as a product of neglect, I had made a brief foray into the creation of an insect garden.  It was a busy summer, and with no conscious design I effectively relinquished our small backyard, surrounded by wooded acres, to the natural world. The resultant floral explosion included several species of goldenrod, common burdock, waist-high perennial ryegrass, jewel weed, and many other rapid colonizers.  By far the most prolific of these was daisy fleabane.  With this impromptu insect garden came insects of numerous species, including a host of damselflies and dragonflies attracted by the newly abundant prey stock.  These skilled aerial predators would sweep methodically above the canopy of our own “grassroot jungle” and reap the good living of summer.

A Twelve-Spotted Skimmer dragonfly (Libellula pulchella)having landed in the author's default insect garden.  Copyright Richard Telford, 2012.

A Twelve-Spotted Skimmer dragonfly (Libellula pulchella) having just landed in the author’s default insect garden. Copyright Richard Telford, 2012.

Interestingly, the dragonfly’s tightly grouped legs, effectively useless for locomotion on the ground, are held in a basket shape in flight, scooping up prey that is largely consumed on the wing. The daisy fleabane explosion had the additional effect of attracting a large cadre of American goldfinches, who rode the bobbing, fragile stalks on even the windiest days, plucking linear white petals by the mouthful, not ten feet from our kitchen windows.  Here, as Teale noted in Near Horizons, we could be “explorer[s] who stayed at home, […] voyager[s] within the near horizons of a hillside.”

Teale’s ten dollars per annum was money well spent.  His insect garden truly altered the course of his life.  The commercial success of Grassroot Jungles afforded him both an income and national recognition, allowing him to quit his job at Popular Science.  In notes he compiled for an autobiography titled The Long Way Home, which was neither finished nor published, Teale writes, “Remember sitting in Insect Garden in evening after hot day and coming to a final decision to quit.”

A female American Goldfinch (Carduelis tristis) eating petals of Daisy Fleabane (Erigeron annuus) less than ten feet from the author's back door.  Copyright Richard Telford, 2012.

A female American Goldfinch (Carduelis tristis) eating petals of Daisy Fleabane(Erigeron annuus) less than ten feet from the author’s back door. Copyright Richard Telford, 2012.

Thus, the site provided a space both for outward observation as well as introspection.  Jumping time in his notes, he continues, “I pack my books etc.  Leave on chill rainy day.  But my heart was bounding.  I was on my own.”  Teale would go on to publish Near Horizons in 1942, for which he would subsequently win the 1943 John Burroughs Medal for distinguished natural history writing, a recognition he prized greatly even up until the time of his death in 1980.  For us, too, the rewards of exploring the near at hand are plentiful.  Such exploration affords us opportunities for observation, for contemplation, for renewal of our sense of wonder, for appreciation of the complex world around us, and for humble acceptance of our small place in that world.