02531nas a2200133 4500008004100000245007900041210006900120520206600189100002902255700002302284700001902307700001802326856005302344 2008 eng d00aMatched Filters, Mate Choice and the Evolution of Sexually Selected Traits0 aMatched Filters Mate Choice and the Evolution of Sexually Select3 a

Background: Fundamental for understanding the evolution of communication systems is both the variation in a signal and how this affects the behavior of receivers, as well as variation in preference functions of receivers, and how this affects the variability of the signal. However, individual differences in female preference functions and their proximate causation have rarely been studied.

Methodology/Principal Findings: Calling songs of male field crickets represent secondary sexual characters and are subject to sexual selection by female choice. Following predictions from the ‘‘matched filter hypothesis’’ we studied the tuning of an identified interneuron in a field cricket, known for its function in phonotaxis, and correlated this with the preference of the same females in two-choice trials. Females vary in their neuronal frequency tuning, which strongly predicts the preference in a choice situation between two songs differing in carrier frequency. A second ‘‘matched filter’’ exists in directional hearing, where reliable cues for sound localization occur only in a narrow frequency range. There is a strong correlation between the directional tuning and the behavioural preference in no-choice tests. This second ‘‘matched filter’’ also varies widely in females, and surprisingly, differs on average by 400 Hz from the neuronal frequency tuning.

Conclusions/Significance: Our findings on the mismatch of the two ‘‘matched filters’’ would suggest that the difference in these two filters appears to be caused by their evolutionary history, and the different trade-offs which exist between sound emission, transmission and detection, as well as directional hearing under specific ecological settings. The mismatched filter situation may ultimately explain the maintenance of considerable variation in the carrier frequency of the male signal despite stabilizing selection.

1 aKostarakos, Konstantinos1 aHartbauer, Manfred1 aRömer, Heiner1 aTregenza, Tom uhttps://dx.plos.org/10.1371/journal.pone.000300501922nas a2200169 4500008004100000245016900041210006900210520130700279653002001586653001201606653001501618653001501633100002101648700002201669700001801691856004301709 2019 eng d00aDiscovery of an acoustically locating parasitoid with a potential role in divergence of song types among sympatric populations of the bush cricket Mecopoda elongata0 aDiscovery of an acoustically locating parasitoid with a potentia3 a

The bush cricket Mecopoda elongata provides a striking example of sympatric intraspecific divergence in mating signals. Five completely dis- tinct song types are found in various parapatric and sympatric locations in South India. While there is convincing evidence that population diver- gence in M. elongata is being maintained as a result of divergence in acous- tic signals, cuticular chemical profiles, and genital characters, the causes of the evolution of such divergence in the first place are unknown. We describe the discovery of a tachinid parasitoid with an orthopteroid hear- ing mechanism affecting M. elongata. This parasitoid may have a role in driving the extraordinary divergence that had occurred among M. elongata song types. Over two years we sampled individuals of three sympatric song types in the wild and retained individuals in captivity to reveal rates of parasitization. We found that all three song types were infected with the parasitoid but that there were significant differences among song types in their probability of being infected. The probability of tachinid parasitiza- tion also differed between the two sampling periods. Therefore, it is pos- sible that parasitoid infection plays a role in song type divergence among sympatric bush cricket populations.

10acryptic species10akatydid10aspeciation10aTachinidae1 aDutta, Rochishnu1 aReddy, Manjunatha1 aTregenza, Tom uhttps://jor.pensoft.net/article/34115/