Below a #grasshopper nymph of the #Chorthippus #biguttulus #group, including closely related European #species C. biguttulus, C. brunneus, and C. mollis. They cannot be clearly differed #morphologically, only by their #songs. B. Gottsberger & F. Mayer (2019) studied mechanisms of #speciesboundarystabilization between C. brunneus/C. biguttulus, which can #hybridize. But hybrids exhibit #songpreferences of C. biguttulus females.

©#StefanFWirth 2025

Ref
https://doi.org/10.1111/jeb.13490

Photos
S.F. Wirth