As I mentioned in the previous blog post, what makes the katydid so interesting is the sound it makes! They make a loud, high-pitched clicking noises in order to attract mates.

However, in most species of katydids, the songs are only produced by the males. If the females also produce songs, they are usually non-repetitive and of such low intensity, and in response to the call of the males (Carlysle, 1975).

The way katydids produce these kinds of sounds are through a process known as stridulation. Typically one forewing possesses a vein modified with a series of cuticular teeth (the stridulatory file), whereas the contralateral wing bears a scraper or plectrum… During the closure of the wings, the scraper on one wing hits the file teeth on the other, creating a sound. Katydids produce two types of sound. These are the pure-tone sounds and the broadband sounds (Ewing, 1989).

Anatomical structure of the Katydid’s wings that creates the mating call

The wings of the katydid are mainly used as a mating call, since this structure is what they use to make the sound. In regards to evolution, besides the wings thickening over time, the function of these structures has not changed (Jost & Shaw, 2006).

Above, I have provided a video of a common meadow Katydid stridulating. Although it is not a broad-winged Katydid, they both still perform the same stridulating technique. It is super interesting to see and the video also includes a pretty awesome clip in slow motion!

References:

Carlysle, T. C. “MORPHOLOGY AND FUNCTION OF FEMALE SOUND-PRODUCING STRUCTURES IN ENSIFERAN ORTHOPTERA WITH SPECIAL EMPHASIS ON THE PHANEROPTERINAE.”

Ewing, A. W. “Arthropod bioacoustics; neurobiology and behavior. 1989.” Comstock, Cornell University Ithaca, NY

Jost, M. C., and K. L. Shaw. “Phylogeny of Ensifera (Hexapoda: Orthoptera) using three ribosomal loci, with implications for the evolution of acoustic communication.” Molecular phylogenetics and evolution 38.2 (2006): 510-530.