Synchronous Crepuscular Flight of Female Asian Gypsy Moths: Relationships of Light Intensity and Ambient and Body Temperatures

Abstract

Female gypsy moths (Lymantria dispar) of Asian heritage studied in central Siberia and Germany exhibit a highly synchronous flight at dusk, after light intensity falls to about 2 lux. This critical light intensity sets the timing of flight behaviors independent of ambient temperature. Flight follows several minutes of preflight wing fanning during which females in Germany and those from a laboratory colony (derived from Siberian stock) raised their thoracic temperatures to 32-33?C at ambient temperatures of 19-22?C. Thoracic temperature of females in free flight exceeded the air temperature (19-22?C) by approximately 11-13?C. The duration of wing fanning was strongly dependent on ambient temperature. In Germany, where ambient temperatures at dusk ranged between 21 and 25?C, females wing fanned for only 2.1 +/- 0.2 (SE) min; in the much colder temperatures prevalent at dusk in Bellyk, central Siberia (11-13"C), females spent 11.2 +/- 0.6 min in preflight wing fanning. The majority (+/

Citation

Charlton, Ralph E.; Carde, Ring T.; Wallner, William E. 1999. Synchronous Crepuscular Flight of Female Asian Gypsy Moths: Relationships of Light Intensity and Ambient and Body Temperatures. Journal of Insect Behavoir. 12(4): 517-531.