Science Past  from the issue of July 30, 1960

LIP-SMACKING GRASSHOPPER — A grasshopper with a talent for lip-smacking has turned out to be quite an unusual insect. Paratylotropidia brunneri Scudder is the first insect known to communicate over fairly long distances by producing an audible sound from the mouth — literally smacking its lips…. Produced at the rate of six or seven per second, usually in groups of four, the grasshopper ticks resemble a shorter, softer version of the ticking song of a katydid. The call can be heard several yards away…. It may be … that the grasshopper’s lip-smacking signal evolved through a stage in which feeding noises were significant. At present it may be effective as a long-range signal only in areas where there are few other sound-producing insects.