Is it a bat or a male? A female moth (Syntomeida epilais, Lepidoptera: Erebidae: Arctiinae) adapts its acoustic signals for defense or courtship

Courtship behavior in the polka-dot wasp moth Syntomieda epilais is the most elaborate acoustic communication system known in the Erebidae. Both males and females must emit their acoustic signals for successful mating under natural conditions in the presence of insectivorous echolocating bats. Females of S. epilais were stimulated during their courtship period (between 02 ÷ 30 and 06 ÷ 30) with playback of conspecific male and female signals and of a sympatric bat attack sequence and their acoustic emissions were recorded. On the third night post-eclosion at the initiation of courtship behavior, females discriminate among these types of acoustic series, responding preferentially to conspecific male signals. In contrast, during the first two nights post-eclosion, they respond strongly to the bat attack sequence but not to conspecific male signals. It is demonstrated that post-mated female moths stop responding to conspecific male signals, while continuing to respond to the bat attack series. These and other novel observations suggest that these female moths can modulate their acoustic signals, according to the stimulating conditions for defense against bats or courtship, by varying their response thresholds and latencies.