First record of Chaetopteroides kosovarorum Ibrahimi & Oláh, 2013 (Insecta: Trichoptera) from the Republic of North Macedonia

Caddisfly specimens were collected with entomological net and ultraviolet light trap during 2016 and 2017 at eight localities in North Macedonia, Kosovo and Serbia. During this investigation we found 13 species. Here we report first record of Chaetopteroides kosovarorum from North Macedonia, as well as new localities for this species in Kosovo and Serbia. This species belongs to an extremely rare genus, inhabiting only few mountainous areas in the Balkans, and until recently has been reported only from its type locality in Kosovo.Beside this, several other rare species were recorded during this investigation such as: Rhyacophila obtusa and Drusus botosaneanui.


Introduction
The Balkan Peninsula is one of the most important biodiversity hotspots for aquatic insects and caddisflies in Europe with a high rate of endemism due to the geological, hydrological and climatic features of the area (e.g. Previšić et al. 2013;Schmidt-Kloiber et al. 2017). However there are still areas where knowledge about caddisfly fauna is still low. This is especially true for North Macedonia, but for several mountainous areas in Kosovo, Serbia, Albania and Montenegro as well. During the past decade, there is an intensification of studies related to caddisfly ecology, biogeography and taxonomy in the Balkan Peninsula (e.g. Graf et al., 2008;Ibrahimi et al. 2012aIbrahimi et al. , b, 2013Ibrahimi et al. , 2014aKučinić et al. 2013;Malicky 2005;Oláh 2010;Oláh et al. 2011;Oláh et al. 2013a, b, c;Previšić et al. 2014;Vučković et al. 2011;Waringer et al. 2009;Živić et al. 2006). Several investigations are also focused in Kosovo and North Macedonia, producing new records and species from the area (Bilalli et al. 2018;Gashi et al. 2015;Ibrahimi et al. 2012aIbrahimi et al. , b, 2013Ibrahimi et al. , 2014aIbrahimi et al. , b, 2016Oláh et al. 2010Oláh et al. , 2011Oláh et al. , 2013aOláh et al. , b, 2011Oláh et al. , 2018Oláh & Kovács, 2013Rimcheska et al. 2015;Slavevska-Stamenković et al. 2016).
The goal of this investigation is to contribute to the distribution and ecology of Chaetopteroides kosovarorum in the Balkan Peninsula.

Data sampling and processing
Adult caddisfly specimens were collected with entomological net and ultraviolet light trap during 2016 and 2017 Kosovo, North Macedonia and Serbia.
Collected samples were preserved in 80 % ethanol. The specimens were identified under a stereomicroscope with determination keys from Malicky (2004) and Kumanski (1985Kumanski ( , 1988

Discussion
Results presented in this paper are continuation of the initiated large scale investigation of caddisflies of the Karadak Mountains. Several first records of rare caddisfly species were presented in this area for Kosovo and North Macedonia during the past period, within these investigations (Bilalli et al. 2018). During the 60ties of the last century two species of the genus Chaetopteroides (Chaetopteroides bulgaricus (Kumanski, 1969) and Chaetopteroides maximus (Kumanski, 1968)) were discovered from Pirin and Vitosha mountains in Bulgaria. For several decades the localities from where these species were described were the only places from where both species were known. During 2013 (Olah et al. 2013) three other species of this genus were described from Kosovo and North Macedonia (Chaetopteroides kosovarorum, Chaetopteroides tunik Oláh, 2013 andChaetopteroides veges Oláh, 2013), all of them from single localities each. Finding of Chaetopteroides kosovarorum in Karadak Mountains during this investigation was somehow unexpected, considering the fact that it was previously considered that all species of this genus have narrow area of distribution. Additional sampling conducted in Serbia revealed that Chaetopteroides kosovarorum is widely distributed in the Balkan Peninsula. Currently it is known from 10 localities. It is probably the ancestral species of this genus from which most of the other species diverged. It was found that this species usually inhabits hypocrenal area of mountainous streams, usually shaded with high vegetation. Most of the localities where this species was found are located above or close to 1000 m, with the exception of station SK4 in Dërmjak village in Kosovo where it was found in considerably lower altitude (620 m). The highest altitude where this species was found is 1565 m asl.
During this investigation we found few other endemic species, contributing thus in the expansion of their known distribution area, namely Rhyacophila obtusa and Drusus botosaneanui. Rhyacophila obtusa is a rare species in the Balkan Peninsula known, only from few mountainous headwater streams in the area. A single specimen of Drusus botosaneanui found during this investigation in station SMK1 Tanushë shows that although in low abundance, this species is widely distributed in the Balkan Peninsula. It is one of the rarest species of the genus Drusus adapted to live in different qualities of streams and rivers, up to the considerably polluted environments.
This investigation adds to the ecology of Chaetopteroides kosovarorum and contributes to the better knowledge of the caddisfly fauna of Kosovo and North Macedonia.