Checklist and provisional atlas of singing cicadas (Hemiptera: Cicadidae) of Bulgaria, based on bioacoustics Author Trilar, Tomi Slovenian Museum of Natural History, Ljubljana, Slovenia https://orcid.org/0000-0003-0636-2881 ttrilar@pms-lj.si Author Gjonov, Ilia Sofia University, Faculty of Biology, Department of Zoology and Anthropology, Sofia, Bulgaria https://orcid.org/0000-0002-4239-9756 gjonov@cicadina.com Author Gogala, Matija Slovenian Academy of Sciences and Arts, Ljubljana, Slovenia matija.gogala@guest.arnes.si text Biodiversity Data Journal 2020 8 54424 54424 http://dx.doi.org/10.3897/BDJ.8.e54424 journal article http://dx.doi.org/10.3897/BDJ.8.e54424 1314-2828-8-e54424 00D3F97C107752E784967973F66E47A8 Cicadatra persica (Kirkaldy, 1909) Distribution General distribution: Southern Europe : Bulgaria (this study), North Macedonia; Eastern Europe : Russia (south European Russia); Middle East : Iran, Israel, Syria, Turkey; Transcaucasia : Armenia, Azerbaijan, Georgia; Central Asia : Pakistan (summarised by Duffels and van der Laan 1985 and Sanborn 2014 ). According to Kudryasheva (1979) the western limit of distribution of Cicadatra persica in the Mediterranean reaches as far as Sicily, but has not been confirmed by recent fieldwork with bioacoustic methods (Thomas Hertach, personal communication). Distribution in Bulgaria : Two male and one female specimen of Cicadatra persica from Sliven are kept in the collections of SOFM and MZPW (Figs 23 , 24 ). These data have never been published before. Cicadatra persica is also mentioned for Bulgaria in literature by Hava (2016) from Sozopol on the Black Sea coast, but in this study, we find that the specimen was misidentified with an unusually coloured Cicadatra atra because of the large differences in body size. Using bioacoustic methods, we searched in Sliven and its surroundings under ideal weather conditions for singing cicadas and in suitable habitat (based on our own field experiences from North Macedonia ( Gogala and Trilar 1998 , Gogala and Trilar 2003 , Gogala et al. 2005 )), but could not detect the presence of Cicadatra persica . Notes Acoustic behaviour : The song with intensive wing clicking was described by Gogala and Trilar (1998) . Some years later, Gogala and Trilar (2003) also described the mechanism of wing clicking. Like many other Cicadatra species, Cicadatra persica also has two types of songs: continuous calling song and courtship song with wing clicks. It is obvious that many species of this genus combine the normal tymbal sounds with clicks produced by wing beats against the body or substrate during their courtship song ( Gogala and Trilar 1998 ). The phrases of a continuous calling song can last for many minutes without interruption (Fig. 25 ). They begin without a distinct pattern of amplitude modulation and sometimes end with one or a few separate, irregular echemes. The frequency range is between 5.8 and 12.4 kHz (at -20 dB level) with maximum amplitude close to 8.4 kHz. In this wide frequency band, there are many small frequency peaks, 670-1300 Hz apart due to the ultrastructure of this song, which consists of pulses (tymbal rib clicks) with a repetition period of about 0.8 to 1.5 ms (repetition frequency 670 - 1250 Hz) ( Gogala and Trilar 1998 ). Courtship song (Fig. 26 ) consists of phrases (duration 5-7 s, average 6 +/- 1.3 s) with a long series (N = 59 +/- 14) of rapidly repeated wing clicks (repetition period 89 +/- 15 ms and repetition frequency approx. 11 Hz), which ends with a loud tymbal echeme with increasing amplitude (duration 186 +/- 26 ms). After a short pause, the wing clicks of the next phrase begin again. The first interval between the clicks is usually a bit longer and the last 2-6 intervals of a phrase are even longer. The interval between the last click and a tymbal echeme is extremely variable and can last between 60 and 600 ms. The frequency spectrum of tymbal echemes is similar to the spectrum of a continuous song, but the wing clicks have a wider frequency spectrum (2-20 kHz) with a maximum amplitude between 3 and 7 kHz (Gogala and Trilar 1998). The clicks always occur in connection with the opening and closing of the forewings. The hindwings remain more or less in the same position during this cycle (Gogala and Trilar 2003). The males singing close together often synchronise the phrases almost simultaneously, so that the tymbal echemes appear, but are slightly shifted for about 50-150 ms (Gogala and Trilar 1998). In addition to these two types of song, a few irregular tymbal echemes are recorded with the same spectrum as the continuous song, usually before the cicadas flew away. This may be an alarm song (rivalry song or distress call) by animals singing or courting too close together ( Gogala and Trilar 1998 ). Selected sound samples of Cicadatra persica are available on the web pages Songs of the European singing cicadas ( Gogala 2020 ). Materials : Suppl. material 5 Diagnosis Cicadatra persica (Fig. 22 ) is an ecologically very peculiar species that lives on steep slopes of river gorges overgrown with thermophilic Mediterranean vegetation.