Nocturnal flight activities of the female Asian gypsy moth, Lymantria dispar (Linnaeus) (Lepidoptera: Lymantriidae)

Abstract

The flight and other behavior of the female Asian gypsy moth, Lymantria dispar, were observed in a net cage under natural photoperiodic conditions in May-August in Yokohama City, Japan. Both virgin and mated females moved by flight between 19:00 and 21:00, which coincided with one to two hours after sunset. Virgin females continued releasing pheromone, i.e., calling behavior, at the new site and sometimes copulated with males at night. If they could not copulate that night and in the subsequent daytime, they flew again the subsequent evening. Mated females started oviposition after their flight and thereafter did not move again. The mean flight speed of a virgin female was estimated as 21.3 m/min. The flight duration was approximately 10 min for both virgin and mated females, and therefore females could move 200 m on average and a maximum of 750 m during one night. These nocturnal activities of the Asian gypsy moth should be considered in order to establish effective control.