The genus Troglocladius Andersen, Baranov et Hagenlund, gen. n. is erected based on T. hajdi Andersen, Baranov et Hagenlund, sp. n. collected at 980 m depth in the Lukina jama—Trojama cave system in Croatia. Morphological features such as pale color, strongly reduced eyes and very long legs make it a typical cave animal. Surprisingly, it has also retained large wings and appears to be capable of flight which would make T. hajdi the first flying troglobiont worldwide, disproving previous beliefs that bats are the only animals capable of flying in complete darkness. Morphologically the new species does not readily fit within any described genus, but shares characteristics with genera both in the tribes “Metriocnemini” and “Orthocladiini”. Bayesian molecular phylogenetic analysis using the markers COI, 18S rDNAs, 28S rDNA, CADI, and CADIV groups it with the genera Tvetenia, Cardiocladius and Eukiefferiella in the tribe “Metriocnemini”. Troglocladius hajdi may be parthenogenetic, as only females were collected. The discovery confirms the position of the Dinaric arch as a highly important hotspot of subterranean biodiversity.

A checklist of aquatic Empididae (dance flies) from Croatia (36 species in subfamily Clinocerinae and 14 species in subfamily Hemerodromiinae) is presented, including information related to the Ecoregions in which species were found and specific species traits. Clinocerinae are represented by five genera, with Wiedemannia Zetterstedt being most species rich (20 species) and Clinocerella Engel least numerous with only one species. In Hemerodromiinae there are 8 species of Chelifera Macquart and 6 species and Hemerodromia Meigen. In addition, a discussion related to the species included and excluded from the list is provided. Most species are univoltine with adults emerging in Spring and Summer, although Kowarzia barbatula Mik and Wiedemannia (Eucelidia) zetterstedti (Fallén) are present throughout the year and Wiedemannia (Chamaedipsia) aequilobata Mandaron occurrs in Winter. The Croatian species assemblage is similar to the well-studied fauna of neighboring Slovenia (63 spp.). It is recommended that some rare species and the streams they inhabit should be considered for greater protection.

Berdeniella keroveci sp. nov. is described based on males collected in Croatia. Current knowledge of the psychodid fauna of Croatia is reviewed and new records of 16 species are presented. Short taxonomic notes on Pericoma pseudocalcilega Krek, 1972, Pneumia balkanica (Krek, 1990), Pneumia mutua (Eaton, 1893), Clogmia albipunctata (Williston, 1893) and Lepiseodina tristis (Meigen, 1810) are given. In total, 33 species of Psychodidae are known to occur in Croatia.