Bioacoustics of Aphrodes diminuta

Remarks. A. diminuta was originally described as a subspecies of A. bicincta based on differences in body size and penis shape ( Ribaut, 1952; Figs. 20–21 ). The original description of A. centrorossica was published after the death of Zakhvatkin in the collection of unfinished manuscripts some of which apparently were not intended for print in the present form; for this reason some taxa were described in these articles in insufficient detail ( Zakhvatkin, 1953 ). Bluemel et al. (2014) treated A. centrorossica as a junior synonym of A. diminuta without any explanation. Based on original descriptions of both forms and on comparison of morphological and acoustic data on West-European populations from Bluemel et al. (2014) with our material we share the opinion that A. diminuta = A. centrorossica .

Male calling signals. Calling signal is a single or regularly repeated phrase. As a rule it consists of several syllables with elaborate temporal pattern ( Figs. 40–41 and 43 ); occasionally the male produces single syllables with irregular intervals up to 10–15 minutes and more ( Fig. 42 ). Each syllable begins with a prolonged succession of variable pulses; occasionally its temporal pattern is irregular. In the initial syllable of a phrase this succession is about 3–6 times longer than in the next ones ( Figs. 40–41 and 43 ). Then follows a more constant part of the syllable consisting of one rather long pure-tone pulse and a train of very short pulses with noise frequency spectra; this train begins quietly and reaches maximum intensity in the second half or in the end ( Figs. 44–49 ). Difference in frequency spectra between pure-tone and noise pulses is clearly visible on the sonogram ( Fig. 49 ). Relative amplitude of different components of a syllable can vary to a great extent ( Figs. 47–48 ). No distinct differences were revealed between the signals of males from different localities even situated at a distance of several thousand kilometres ( Figs. 44–48 ).