Not all Panorpa (Mecoptera: Panorpidae) scorpionfly mating systems are characterized by resource defence polygyny

Polygynous mating systems are classified according to the means that males use to control access to females. When resources critical for female reproduction are unevenly distributed or spatially clumped, monopolization of these resources may give males access to multiple females, leading to a resource defence polygynous mating system. Panorpa scorpionflies are frequently cited as an example of resource defence polygyny (RDP). Studies on American species have indicated that males monopolize food resources of different size according to their own body size, leading to differential mating success for males obtaining resources of different quality. Previous studies on European scorpionfly mating systems, however, cast some doubt on the existence of RDP. Using the same experimental approach as in the earlier studies on American Panorpa, we examined two European scorpionfly species (Panorpa alpina and P. vulgaris) to determine whether their mating systems can be characterized as RDP. Our results confirmed that scorpionflies are polygynous, but also showed that polygyny is not based on the monopolization of resources. Thus, we do not think that Panorpa scorpionflies can universally be characterized as resource defence polygynous.