Recent Distribution and Ecological Notes on the Dryopid Beetle Pomatinus substriatus Müller, 1806 (Dryopidae: Coleoptera) in Serbia

The aim of this paper is to present recent distribution and to provide some ecological notes on the dryopid beetle Pomatinus substriatus (Muller, 1806) in Serbia on the basis of field research in the period from 2010 to 2013. During the research, P. substriatus was recorded at 36 localities situated at 27 streams and rivers in total and one reservoir in Serbia (the Bojnik Reservoir). The species was found to be the dominant water beetle species at 12 localities/watercourses: The Mosna/Porecka River, Gornjak/Mlava, Neresnica/Pek, Kusici/Pek, Usce/ Studenica, Lepenac/Rasina, Svođe/Lužica, Vlasotince/Vlasina, Krivi Do/ Visocica, Trnski Odorovci/Jerma, Lucani (upstream Stenjevac Brook confluence)/Bjelica and the Gugaljski Most/Zapadna Morava River. According to the national watercourse classification (Official Gazette of the Republic of Serbia, 74/2011), most of the watercourses where the species was recorded belong to Type 3 (small to medium streams, altitude to 500 m, with domination of large fractions of substrate). The highest abundance of adults was detected in August and September of 2013 at 3 localities (Mosna/Porecka River, Lepenac/Rasina and Svođe/Lužnica). Larvae were very rare in samples and found only at two localities (Usce/Studenica, June 16 2011 and Leskovac/Veternica, May 29 2012). Considering the species' habitat preference, it was found that larvae and adults of P. substriatus predominantly inhabit stretches of streams with domination of medium or large-sized stones, while occasionally it can be found in small stagnant water puddles. Additionally, some individuals were found in fragments of tree trunks and rotting branches submerged in water. The population trend of P. substriatus could not be assessed based on the collected data. The objective of the study is to contribute to the general knowledge of the species autecological characteristics and distribution in Serbia.