Behaviour 2019
Evolution and plasticity of a newly discovered drumming behavior
E Dale Broder1, Aaron W Wikle1, Sam M McCammant2, James H Gallagher1, Robin M Tinghitella1. 1University of Denver, Denver, CO, United States; 2St Ambrose University, Davenport, IA, United States

Both selection and plasticity are hypothesized to play important roles in coupling new signals with receiver responses. Sexual signals are often complex, multimodal, and shaped by both natural and sexual selection. We asked if Pacific field crickets produce substrate-borne vibrations in addition to the airborne acoustic and chemosensory signals used in courtship. This system is evolving rapidly; within the past 20 years three new prominent male morphs have arisen (silent, purring, and rattling), each producing different, attenuated airborne songs compared to ancestral males. We documented low-frequency substrate-borne vibrations produced by wing movements, and frequency but not amplitude differed between morphs. We also observed foreleg drumming, a common type of vibrational signal in arthropods that has not been described in this species. Drumming was more common in the morphs with quieter airborne song than in ancestral type males. To explore the role of plasticity, we reared males in two acoustic treatments and found that both male courtship behavior and female responses to males were developmentally plastic.