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 Cicadetta brevipennis s. lat. Fieber, 1876 Distribution General distribution (only acoustically-validated data): Southern Europe : Bulgaria, Croatia, Italy, Romania, Serbia, Slovenia; Central Europe : Austria, Hungary (summarised by Hertach et al. 2016 ). Distribution in Bulgaria : During our research, Cicadetta brevipennis s. lat. was found for the first time in Bulgaria and some of the song recordings were used in the research of Hertach et al. (2016) . The species was found at 33 localities in the eastern Danubian Plane, southern Lower Mountain Pre-Balkan, southern Lower Mountain Pre-Balkan, southern Balkan Mts., Pirin Mt., Tundzha-Burgas Valley, eastern Rhodope Mts. and Strandzha Mt. (Fig. 39 ). In this survey, the majority of the population was found between sea level and 600 m (97% of the population) (Fig. 40 ). It was also recorded at Tvarditshki Prohod on Eleno-Tvarditshka Planina (1079 m a.s.l.), which is extremely high for this species. Notes Acoustic behaviour : The song was described by Gogala and Trilar (1999) , Gogala (2002) , Gogala and Trilar (2004) , Trilar and Holzinger (2004) , Gogala (2006) , Trilar et al. (2006a) and Hertach et al. (2016) . The calling song (Fig. 41 ) is a repetitive pattern of a long echeme (duration 4.2 +/- 3.3 s) increasing in intensity, followed after a short interval (duration 0.05 s) by a short and loud echeme (duration not exceeding 0.05 s) ( Boulard 1995 , Gogala 2002 , Gogala and Trilar 2004 ). The next long and short echeme sequence follows after a pause of 1.1 +/- 0.3 s ( Hertach et al. 2016 ). The dominant frequency is 14.6 +/- 0.8 kHz ( Hertach et al. 2016 ). Selected sound samples of Cicadetta brevipennis are available on the web pages Songs of the European singing cicadas ( Gogala 2020 ). Materials : Suppl. material 9 Diagnosis Hertach et al. (2016) based on acoustic, morphological, molecular, ecological and spatial data of Cicadetta brevipennis s. lat. (Fig. 38 ) from Spain, France, Italy, Switzerland, Germany, Austria, Slovenia, Croatia, Serbia, Bulgaria and Romania recognised five lineages. Cicadetta petryi (Schumacher, 1924) was recognised as a valid species and Cicadetta brevipennis was grouped into three subspecies. However, some populations of Cicadetta brevipennis s. lat. from Bulgaria were recognised as separate lineage and may be a completely new taxon, but the dataset was not informative enough for the conclusions ( Hertach et al. 2016 ). In the meantime, we have collected new data from Bulgaria and Greece and further comprehensive analysis is needed to clarify the systematics for this region.