Cosmoderus femoralis Sjöstedt, 1901

Material examined: 3 males [CH8626 (SR, TI, CHR), CH 8627 (SF, TI, CHR), CH8628 (CHR)], CAMEROON, 2018, obtained alive from P. Grabowitz, Cologne .

Bioacoustics. The tegmina of Cosmoderus femoralis males show the typical Hetrodini shape (Fig. 2). The left file carries 65 relatively small teeth (Table 1; Fig. 4), much more than in the species described above. The recorded male produced its calling song only at night. In the beginning it made crescendoing series of syllables lasting a few seconds, but these sequences quickly became longer ending in very long trills (Fig. 5A, 8A; longest recorded uninterrupted songs 46 and 66 minutes). The spectrum of the song is typical for Hetrodini with the peak at 16 kHz (Fig. 6).

Genitalia. The genitalic sclerites consist of a large, central, triangular, basal part (titillator) with a very short rectangularly-bent tip and two smaller lateral elements (Fig. 9A).

Chromosomes: 2n = 25 (24 + X0), FN = 29; pairs 1 and 2 submetacentric (= bi-armed), 3–12 and X chromosome acrocentric (3 males); thin C-positive paracentromeric bands in all of the chromosomes and an interstitial one in the first pair of autosome (Fig. 12A).