The island's tiniest dragons seldom stir fear, even among those with little love for life on four or more legs, for they stalk close to the ground and cling to the shady side of herbs and grasses that ring still ponds and stagnant drains. Barely an inch in length, Coenagrionid damselflies in a subfamily known as midgets are among the smallest living odonates, being mere pins of veined wing and slivery body guided by bicolour eyes and an appetite for even flimsier insects that coast through the undergrowth between the banks and low bushes. In turn, their forays into the open, inconspicious as they are, render the minute hunters vulnerable to the swoops of sharp-sighted fellow zygopterans with the speed and power to pluck a wisp from the air.
Locally, Agriocnemis femina is the most common member of a genus known as wisps, dartlets or shadeflies. At home by waters too shallow or squalid for more finicky damsels, the variable wisp is barely apparent to casual visitors of urban wetlands who would scarcely stoop to survey the scummy fringes of lily pools and puddles in the park. Seldom aloft, nubile males are clad in a powdery bloom of blueish grey and white and might be taken for a spot of water or shiny stain on the stems they clutch. Immature males don a coat of green and black with orange tail-lights, which is confusingly mirrored by adult females that appear to be andromorphs of their younger brothers. Adding to the mix is the cherry red garb of underaged girls, whose warning colours seem to deter neither old men nor young studs.
Three other species of wisps, including one recent discovery distinguished by the expression of pruinescence only in adult females, occur in Singapore. Agriocnemis nana, both sexes of which bear baby-blue abdomens, is a rare dwarf confined to the marshy edges of the island's wooded heartlands. A third species, Agrocnemis pygmaea, was last recorded in 1858, despite sharing the habitat preferences of the variable wisp, young males of which closely resemble adult pygmaeas and can be reliably told apart only by examining their terminal appendages.
It's not clear if the distributional anomalies of the genus are artifacts of prehistorical biogeography or the result of a century of anthropogenic fragmentation. Variable wisps, given their tolerance for disturbed habitats, probably find enough stepping stones in the ditches that criss-cross the country to escape the ravages of restless urban planners. The dwarf wisp is a prisoner of intractable avenues. Agriocnemis minima is a mystery, for it occurs in Thailand, Borneo and the Malay Peninsula but was not known from Singapore. Unknown barriers to dispersal may have prevented some from reoccupying their colonial haunts. But perhaps all it would take for these midgets to reach fresh territories might be an upward gust strong enough to lift teneral fliers or gravid dames high into the trade winds or tropical storms that sweep over shallow seas and seed the continents with life on closed wings.
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