Singing and cryptic speciation insects.

Biologists have long known of the existence of 'inaudible' songs in insects, but recent work has shown such substrate-borne or near-field signals to be virtually ubiquitous, and often correlated with high numbers of sibling species. In a sexual context, silent singing has the formidable advantage of privacy: neither predators nor sexual competitors can listen and disrupt. Privacy enhances species recognition by promoting signal complexity. It also encourages the evolution of intricate signals in females as well as males, leading to obligatory dueting behavior during pair formation. Current evidence suggests that song divergence in dueting taxa can facilitate rapid, sympatric speciation.