Perennial emergence of aquatic dipteran families (Insecta, Diptera) at tufa barriers in the Plitvice Lakes National Park

Dvokrilci (Insecta, Diptera) su brojem porodica i brojnošću jedna od najznačajnijih skupina vodenih kukaca koji su razvili brojne prilagodbe na vodeni okoliš i nalazimo ih u svim vodenim staništima. Ličinke i kukuljice žive u vodenim staništima, a emergencijom prelaze na kopno. Odrasle jedinke dvokrilaca prikupljane su mjesečno na sedrenim barijerama Labudovac i Kozjak-Milanovac u Nacionalnom parku Plitvička jezera tijekom 13 godina, od veljače 2007. do kraja 2019. godine. Cilj istraživanja je utvrditi raznolikost i sličnost između sastava i strukture porodica vodenih dvokrilaca na obje sedrene barijere tijekom 13 godina s naglaskom na emergencijske značajke najzastupljenijih porodica i preferenciju prema mikrostaništu. Na sedrenoj barijeri Kozjak-Milanovac postavljeno je 6 emergencijskih klopki, a na sedrenoj barijeri Labudovac 6 emergencijskih klopki od 2007. do 2011. godine te 7 emergencijskih klopki od 2012. do 2019. godine. Klopke se međusobno razlikuju po supstratu i brzini strujanja vode. Prikupljeni materijal izoliran je do redova, a red Diptera određen je do porodica. Tijekom 13 godina prikupljeno je i determinirano 79222 jedinki iz 13 porodica vodenih dvokrilaca na sedrenoj barijeri Labudovac te 66785 jedinki iz 16 porodica vodenih dvokrilaca na barijeri Kozjak-Milanovac. Na sedrenoj barijeri Labudovac dominira porodica Chironomide dok na sedrenoj barijeri Kozjak-Milanovac porodica Simuliidae. Vrhunac emergencije na obje sedrena barijere zabilježeni su u ljetnim mjesecima za vrijeme viših temperatura vode i kod nižeg protoka vode. Porodice Empididae, Muscidae, Psychodidae i Simuliidae pokazuju pozitivnu korelaciju između abundacije i brzine strujanja vode te prefereiraju mahovinu od prisutnih substrata, dok ostale porodice nisu pokazale statistički značajnu sklonost prema određenom tipu mikrostaništa ili brzini strujanja vode.True flies (Insecta, Diptera) are with number of families one of the most important groups of aquatic insects, which have developed numerous adaptations to the aquatic environment and are found in all aquatic habitats. Larvae and pupae live in aquatic habitats, and with emergence they transfer to terestrial habitats. Adult speciment were collected monthly at the Labudovac and Kozjak-Milanovac tufa barriers in the Plitvice Lakes National Park for 13 years, from February 2007 to the end of 2019. The goal of the study is to determine the diversity and similarity between the composition and structure of aquatic Diptera at both tufa barriers over 13 years with emphasis on the emergence characteristics of the most represented families and preference for microhabitat. 6 emergence traps were installed at the Kozjak-Milanovac tufa barrier, and 6 emergence traps were present at the Labudovac tufa barrier from 2007 to 2011 and 7 emergence traps from 2012 to 2019. The traps differ from each other in the substrate and the water flow rate. The collected material was isolated up to the order, and the order Diptera was identified up to the family level. During 13 years, 79222 individuals from 13 families of aquatic Diptera at the Labudovac tufa barrier and 66785 individuals from 16 families of aquatic Diptera at the Kozjak-Milanovac tufa barrier were collected and identified. At the Labudovac tufa barrier the dominant family is Chironomidae, while at the Kozjak-Milanovac tufa barrier the dominat family is Simuliidae . The peak of emergence at both tufa barriers was recorded in the summer months during higher water temperatures and at lower water discharge. The families Empididae, Muscidae, Psychodidae, and Simuliidae show a positive correlation between abundance and water flow rate and they prefere moss from all present substrates, while other families did not show a statistically significant preference to a particular type of microhabitat or water flow rate