Wing-waving behaviors are used for conspecific display in the Japanese scorpionfly, Panorpa japonica

Species of scorpionfly (Mecoptera) in the family Panorpidae perform wing-waving behaviors, whereby they rotate their front and rear wings at the same time. Previous studies have suggested that a male, which carries food for use as nuptial gifts for females, performs the wing-waving behavior when the male gives the gift to a female or competes with other males. However, when and how the wing-waving behavior occurs during a series of nuptial giftings and male–male competitions have not been investigated. Therefore, we here observed the role of wing-waving behavior during the processes of giving nuptial gifts and male–male competition in the Japanese scorpionfly Panorpa japonica in the laboratory and field. Unlike previous studies, only males performed wing-waving behavior toward females, while females did not exhibit the behavior in the wild. Also, males always performed wing-waving behavior before male–male competition. After a male–male competition, winner males continued wing-waving behavior, but loser males never performed the behavior against the winner male. A comparison of wing-waving behaviors before competitions between winner and loser males showed that the frequencies of wing-waving behaviors were higher in winner than in loser males. The present results suggest that the wing-waving behavior functions in the inter-sexual and intra-sexual selection in P. japonica. Digital video images related to the article are available at http://www.momo-p.com/showdetail-e.php?movieid=momo210513pj01a and http://www.momo-p.com/showdetail-e.php?movieid=momo210513pj02a and http://www.momo-p.com/showdetail-e.php?movieid=momo210513pj03a.