An experimental study of the refusal display in the damselfly Platycnemis pennipes (Pall.) (Zygoptera: Platycnemididae)

Females in tandem or having been in tandem, single females laying eggs and juvenile females can demonstrate refusal display to conspecific males and those of certain closely related spp. Refusal display has some successive states depending on the male’s persistence. The responses of P. pennipes males to the refusal display by females were studied by means of 11 models. These differed in the presence and position of the abdomen. Female models with abdomens that rise at angles of 45" and 90" obtained the largest number of negative reactions. At an extreme state of refusal display (abdomen rises to maximal angle) the number of positive reactions by a male rose, but seizure of the female in tandem was hampered. Males demonstrate a threat display that is similar to female refusal display. In the natural environment threat display probably decreases the frequency of homosexual contacts, whereas refusal display of females leads to an economy of male time and energy.