THE ROLE OF COURTSHIP SONGS IN REPRODUCTIVE ISOLATION AMONG POPULATIONS OF GREEN LACEWINGS OF THE GENUS CHRYSOPERLA (NEUROPTERA: CHRYSOPIDAE).

Male and female lacewings tremulate during courtship, establishing duets that always precede copulation. Three distinct courtship songs are found in populations of the green lacewing Chrysoperla plorabunda (P1, P2 and P3 song morphs). Analysis of five features of the songs for individuals collected from Connecticut, Idaho, Oregon and California showed few differences within song morphs, but sympatric song morphs differed significantly in temporal features of the songs and their mode of presentation. Playback experiments using recorded songs were performed on females with all possible sympatric and allopatric combinations of females and recorded songs. The results showed that females strongly prefer to duet with recordings of males of their own song type and usually showed no responses to songs of other types. Thus, song differences are effective barriers to reproduction between the sympatric morphs. Our results support the hypothesis that the three song morphs are true biological species.