Novel Wing-Flashing Behavior in a Scorpionfly (Panorpa debilis) May be Competitive

Abstract

Scorpionflies (Mecoptera: Panorpidae) are important models for studying sexual selection and mating strategies. However, much is still unknown about their behavior and natural history. Here we describe a wing-flashing behavior in a population of Panorpa debilis Westwood from central New York. Wing-flashing has been previously observed, but not described in Mecoptera. We use a combination of direct observation and video analysis in an attempt to understand the motivation behind this behavior: is wing-flashing behavior used for attraction of mates, for control of food resources, or perhaps neither? If wing-flashing is involved in mate attraction, we would expect skewed wing-flashing ratios between males and females and a high rate of wing-flashing aimed at conspecifics of the opposite sex. If the behavior is instead used for intraspecific competition for resources, we would expect a high degree of wing-flashing aimed at conspecifics of the same sex or indiscriminate of sex. We demonstrate that this behavior is non-random — and most likely competitive in nature — by showing that wing-flashing preferentially occurs near other individuals, and by comparing wing-flashing rates across males and females in a variety of situations. Both sexes used wing-flashes in response to the opposite sex, though most wing-flashes were female to female signals. Wing-flashing was even observed as a response to potentially competitive arthropods like harvestmen (Leiobunum spp.). In addition to their suitability as study organisms for mating behavior, P. debilis, may be a useful organism for studying animal communication and signaling.