The Importance of Low-Frequency, Substrate-Borne Sounds in Lacewing Communication (Neuroptera: Chrysopidae)

Courting green lacewings of Chrysopa carnea Stephens, C. downesi Banks, and several other species communicate with their partners by exchanging acoustical signals produced by vigorous jerking of the abdomen. Intraspecific communication was unaffected when an area of microtrichia associated with a possible stridulatory structure was excised from the wing of a sexually receptive C. carnea male. Additionally, no high-frequency audio sounds were detected by analysis of oscillographs; however, males and females of C. carnea and C. downesi responded to recordings of conspecific calls when the low-frequency oscillations were transmitted to a compliant substrate and when all high-frequency information was filtered out. Therefore, exchange of low-frequency substrate oscillations is sufficient for intraspecific communication in the lacewing species studied. Evolutionary implications are discussed briefly.