Cover Caption: The cover image is based on the Research Article Proteomic diversification of spermatostyles among six species of whirligig beetles by Roberto Gomez et al., https://doi.org/10.1002/mrd.23745.

Whirligig beetle sperm travel cooperatively through the female reproductive tract attached to a spermatostyle, a poorly studied rod-like structure. Proteome characterization revealed that spermatostyles are comprised of a restricted set of proteases and possess catalytic activity. Spermatostyle composition was also found to codiversify with spermatostyle length and female tract morphology.