A New Piece in the Puzzle of Insect Flight

Three scientists by the names of Stephen Yanoviak, Mike Kaspari, and Robert Dudley, of the University of Arkansas at Little Rock, University of Oklahoma and the University of California-Berkeley respectively, have recently been studying the Arboreal bristletails (pictured above) in the Amazon Forest. These insects do not have wings but rather they have a filament on their bodies that they can manipulate and use as a rudder system. Armed with the filament, the median caudal filament, the insect can safely maneuver through the air from tree to tree in tropical forests.

This insect has long been considered an evolutionary precursor to many winged inhabitants of the Amazon Forest. “Directed aerial descent, such as gliding and maneuvering, may be an important stage in the evolution of winged flight” says Dr. Yanoviak. A study in Peru where these insects were dropped off of high branches proved the effectiveness of the median caudal filament. With the filament present approximately 90% of the dropped insects successfully landed on an opposing tree. When the filament was removed the number of bristletails landing successfully dropped significantly.

The evolution of something as complicated as flight has always been an interest to biologists. “The existence of aerial control ability in a wingless insect and its habitat in trees is consistent with the hypothesis of a terrestrial origin for winged flight in insects,” Yanoviak said. This discovery helps add another piece to the puzzle of the evolution of flight.

-Jillian O'Keefe (Group C week 6)