Role of vision throughout the flight initiation sequence of the Colorado potato beetle

Abstract

AbstractThe role of vision in the flight initiation sequence of the Colorado potato beetle,Leptinotarsa decemlineata(Say) (Coleoptera: Chrysomelidae), was assessed by comparing the behavioral sequences and frequencies of takeoffs of untethered and tethered beetles with and without vision. Results showed that vision plays a critical role in the successful completion of the launch and the maintenance of lift for the adult Colorado potato beetle. The sequence was interrupted immediately before or during the lifting of the mesothoracic legs or before the launch for most blind beetles. Liftoffs of untethered beetles over a 1-h period in a flight chamber were reduced significantly, by 77%, in blind beetles compared with normal beetles. In addition, the preponderance of upward (dispersal) flights following successful liftoffs of normal beetles was replaced by a preponderance of downward (short) flights for blind beetles. Blind beetles that did not have to launch themselves because they were tethered initiated flight as frequently as tethered normal Colorado potato beetles. The duration and repeatability of flights initiated by tethered blind Colorado potato beetles were also similar to those of flights initiated by tethered normal Colorado potato beetles in a stationary environment. Together, the results of the tests with untethered and tethered beetles indicate that vision is a key factor during flight launching and for flight continuation.