On August 10, 1926, a Stinson Detroiter
SM-1 six-seater monoplane took off from the rudimentary airstrip at Tallulah,
Louisiana. The Detroiter was the first airplane built with an electric starter
motor, wheel brakes, and a heated cabin, but it was not a good climber, so the
pilot leveled off quickly, circled the airstrip and surrounding landscape, held
open the specially fitted sticky trap beneath the plane’s wing for the
designated ten minutes, and soon returned to land. As he touched down, P.A.
Glick and his colleagues at the Division of Cotton Insect Investigations of the
U.S. Bureau of Entomology and Plant Quarantine ran out to meet him.
It was a historic flight: the first attempt
to collect insects by airplane. Glick and his associates, as well as researchers
at the Department of Agriculture and at regional organizations such as the New
York State Museum, were trying to discover the migration secrets of gypsy
moths, cotton bollworm moths, and other insects that were munching their way
through the nation’s natural resources. They wanted to predict infestations, to
know what might happen next. How could they contain these insect enemies if
they didn’t know where, when, and how they traveled?
Before Tallulah,
high-altitude entomology had barely got off the ground. Researchers sent up
balloons and kites fitted with hanging nets, climbed up pylons, and pestered
lighthouse keepers and mountaineers. But armed now with the new airplane
technology, Glick went down to Tlahualilo in Durango,
Mexico. There, 3,000 feet above the valley plain, his pilots trapped the pink
bollworm moth, a feared invader of the U.S. cotton crop. Face-to-face with the
unanticipated scale of his task, Glick wrote tersely that “the pink bollworm
moths are carried in the upper air currents for considerable distances.”
There were only a few flies
and wasps in that first trap at Tallulah. But over the next five years the
researchers flew more than 1,300 sorties from the Louisiana airstrip and
captured tens of thousands more insects at altitudes ranging from twenty up to
15,000 feet. They generated a long series of charts and tables, cataloguing
individual insects of 700 named species according to the height at which they
were collected, time of day, wind speed and direction, temperature, barometric
pressure, humidity, dewpoint, and many other physical variables. They already
knew something about long-distance dispersal. They had heard about the
butterflies, gnats, water-striders, leaf-bugs, book-lice, and katydids sighted
hundreds of miles out on the open ocean; about the aphids that Captain William
Parry encountered on ice-floes during his Polar expedition of 1828; and about
those other aphids that, in 1925, made the 800-mile journey across the frigid,
windswept sea between the Kola Peninsula and Spitzbergen in just 24 hours. Still, they were taken aback by the
enormous quantities of animals they were discovering in the air above Louisiana
and unashamedly astonished by the heights at which they found them. All of a
sudden, it seemed, the heavens had opened….