The function of the female mimic signal in Enchenopa binotata treehoppers

Some animals mimic behaviors or signals of conspecifics while courting.
Sexual mimicry is beneficial when it increases
reproductive success. We explored the function of a novel form of
sexual mimicry in the courtship display
of male Enchenopa treehoppers. Males produce plant-borne
vibrational advertisement signals, to which females respond.
Interestingly, males also produce a female mimic signal, and we
experimentally tested its function. First, with a female priming
hypothesis, we tested if this signal would increase female response.
However, females were as likely to respond to playbacks with or without
this. Second, with a male inhibition hypothesis, we tested if the mimic
signal would inhibit competing males. However, males were as likely to
produce displays after playbacks with or without the mimic signal. Third,
with a self-boost hypothesis, we tested if males performing the mimic
signal would show higher signaling effort. Males that produced the mimic
signal had higher signal rates and longer signals than males that did not
produce it. We suggest that the mimic signal provides the males with
positive motivational feedback. Consequently, the evolution of sexual
mimicry –and signal repertoires– may be influenced by the effects on the
sender itself, besides the effects on the audience.