LEPIDOPTERAN LEVITATIONS

On a morning about fifteen years ago, I took a pleasant stroll not far from the little city of Rivas, along Lake Nicaragua's western shore. As I walked, a dark splotch bobbing on the water's surface caught my eye, and I waded out to retrieve a large, lovely, and very dead butterfly. I set it on a drawing pad to dry in the sun before painting the watercolor studies from which I later completed the piece on the left. The insect was unfamiliar to me. Its intricately vermiculated underwings reminded me of the Caligo owl butterflies I knew well, and indeed, it turned out to be a close relative. Upon my return to the states, I consulted the literature. My sketch corresponded to Opsiphanes tamarindi, but I felt insecure identifying it as such. That species had never been recorded in the region, and the nearest suitable habitat was well over 100 miles away.

A hundred miles is a long way to walk, and on first blush, it's hard to credit dainty butterflies with making such transits, but it would be wrong to underestimate their powers. The autumn migrations of American Monarchs (Danaus plexipus) are legendary, and that species' sturdy four-inch wingspan has carried it across the Pacific to new havens in Australia and Hawaii. It regularly shows up on the British Isles as well. It's a little staggering to imagine how many of these insects end up floating pelagically, in the position of my Opsiphanes.

As a boy of eight or nine, I found a moth whose wings spanned over six inches. It clung, nearly dead, inside a cinder block, sheltering from the rain. Its dark gray, almost black wings bore a light zig-zag band that brought a stark beauty to its otherwise drab appearance. It would be several years before I learned that I had found a Black Witch (Ascalapha odorata), a common Neotropical species that disperses widely after metamorphosing. Finding one in Utah was not terribly surprising; they regularly cross the Canadian border.

Small and frail though they may seem, many insects and other invertebrates are well adapted to disperse across amazing distances. Tiny creatures belonging to dozens of orders can traverse thousands of miles within a fleeting lifespan. Occasionally they colonize a new land. More often, their lives end tragically—lost, helpless in the jet stream, or buried at sea, or burning out in a hostile climate, like the Black Witch that died trembling at the bottom of a terrarium in northern Utah—an inauspicious end to a several thousand mile odyssey made by an insect that might have started life as a caterpillar in a Mimosa tree, not far from the little city of Rivas, along Lake Nicaragua's western shore.
_____________________
upper: OPSIPHANES TAMARINDI (1995) Acrylic 11" x 7"
lower: BLACK WITCH 1994) Acrylic 5" x 3"