Data for: A novel cricket morph has diverged in song and wing morphology across island populations

Divergence of sexual signals between populations can lead to speciation,
yet opportunities to study the immediate aftermath of novel signal
evolution are rare. The recent emergence and spread of a new mating song,
purring, in Hawaiian populations of the Pacific field cricket
(Teleogryllus oceanicus) allows us to investigate population divergence
soon after the origin of a new signal. Male crickets produce songs with
specialized wing structures to attract mates from afar (calling) and
entice them to mate when found (courtship). However, in Hawaii, these
songs also attract an eavesdropping parasitoid fly (Ormia ochracea) that
kills singing males. The novel purring song, produced with heavily
modified wing morphology, attracts female crickets but not the parasitoid
fly, acting as a solution to this conflict between natural and sexual
selection. We’ve since observed increasing numbers of purring males across
Hawaii. In this integrative field study, we investigated the distribution
of purring and the proportion of purring males relative to other morphs in
six populations on four islands and compared a suite of phenotypic traits
(wing morphology, calling song, and courtship song) that make up this
novel signal across populations of purring males. We show that purring is
found in varying proportions across five, and is locally dominant in four,
Hawaiian populations. We also show that calling songs, courtship songs,
and wing morphology of purring males differ geographically. Our findings
demonstrate the rapid pace of evolution in island populations and provide
insights into the emergence and divergence of new sexual signals over
time.