Dozens of dragonflies are flitting about the engineering quadrangle when I arrive in the morning. The sun is still low but already blinding. Light glints off wings and abdomens, turning them into harmless (to humans) tracer bullets ricocheting over the grass. I wanted to identify the species and understand the frenzy so I contacted the Department of Ecology and Evolutionary Biology, and got an answer from assistant professor Volker Rudolf:
“I'd guess they are Pantala flavescens, the Wandering Glider. They form migrating swarms this time of the year. They are indeed feeding, and this is when they are migrating and laying eggs in puddles & ponds. As an interesting side note, this species occurs worldwide and in some parts of the world they engage in the longest migration of any insect. The monarch [butterfly] travels a maximum distance of about 3,000 miles. Pantala travels 11,000 miles across the Indian Ocean from India to South West Africa, twice a year.”
Strength and beauty linked is always impressive, in insect or poem. Pantala is the Ur-dragonfly, a perfect killer, so well-adapted it has colonized the world. The authors of the magisterial Dragonflies of North America (Scientific Publishers, rev. ed. 2000) bluntly call Pantala flavescens “The one cosmopolitan dragonfly.” In Dragonflies through Binoculars: A Field Guide to Dragonflies of North America (Oxford University Press, 2000), Sidney W. Dunkle writes:
“The world’s most evolved dragonfly, it 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. Over the ocean they fly day and night for thousands of miles…It is the only dragonfly found around the world, breeding on every continent except Europe. On many oceanic islands, such as Easter Island, it is the only dragonfly.”
In “September Swamp” (The Door in the Wall, 1992), Charles Tomlinson refers with memorable precision to the “swift, aerial transaction” of dragonflies, and says “All movement is below, save for the blue / Crackle of the dragonflies through static air.” I remember sitting at the end of a dock on a lake in northern Ohio, fishing and listening to the buzz of dragonflies – “crackle” is a better word, reinforced by “static” – as they investigated the rod, the line and me. It was an intimate sound, less like the public drone of cicadas than the private purr of a cat. In Cracks in the Universe (2006), Tomlinson includes “Dragonflies”:
“Dragonflies
flock to this garden
like swallows in autumn
(it is high summer):
such glamour
in predation, scissor-jawed
and single-minded,
they radar their way
past obstacles,
flying in formation,
pilots who are their own craft,
speed their sole stratagem:
cold that means death to them
makes them begin
to disappear just as the dark
comes cooling in.”
Tomlinson confirms my first impression of the dragonflies in the quad -- they resemble swallows, dipping and diving as they harvest airborne meals. “Radar” works for bats, not dragonflies, but I like “pilots who are their own craft, / speed their sole stratagem.” I can’t imagine catching a dragonfly in flight with my hands, or grasping a good poem after the first read.
[For another post on dragonflies and a good poem about them, go here.]
Thursday, July 14, 2011
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