Description of the song of Isophya beybienkoi (Orthoptera, Tettigonioidea)

The male calling song and female reponse song of Isophya beybienkoi, an endemic species of the Slovak Karst, are described for the first time and illustrated by oscillograms. The male calling song is a long syllable-sequence composed of "A" and "B" type syllables. The arrangement scheme of these syllable-types is AAA...A - BAAA...A - BAAA...A - BAAA...A and so on (where AAA...A means a varying number of "A" syllables and "-" is a distinctively longer intersyllable interval). This complex song is highly characteristic and differs clearly from all the songs that have been described in this genus until now confirming the validity of this interesting species. Females emit a short response song with a rather variable pulse repetition pattern during the intersyllable interval immediately after the "B" syllable of the male. Basic statistics for several rhythmic characters of the song of both sexes are presented.