Contribution to the knowledge of the Odonata fauna of Bosnia and H erzegovina – Results of the ECOO 2012

. As a part of the 2 nd European Congress on Odonatology (ECOO 2012), which was held in the beginning of July 2012 in Belgrade (Serbia), a post congress excursion to Bosnia and Herzegovina was organized. Between 6 and 12 August 2012 , altogether 36 localities in three biogeographical regions throughout Bosnia and Herzegovina were surveyed, and 52 dragonfly species were found. This represents 83% of the hitherto recorded dragonfly species for the country. The most significant results are the second record and a new locality of Somatochlora metallica , second record of Coenagrion hastulatum, and first observation of the strong population of Lindenia tetraphylla for the country. New records of rare and/or threatened species, i.e. Coe nagrion ornatum , Ceriagrion tenellum, Caliaeschna microstigma, Cordulegaster heros and Selysiothemis nigra , are also reported. The records of the most interesting species are briefly discussed from the aspects of biogeography and nature conservation.


Introduction
Bosnia and Herzegovina is a small country located in the western part of the Balkan Peninsula (Fig. 1).Karst mountains cover the largest, central part of the country separating the southern and the Mediterranean area of Herzegovina from the lowland area of North Bosnia.As a consequence, three biogeographical regions can be distinguished: the Mediterranean, Alpine and Continental (Kulijer et al. 2013, Redžić et al. 2008).Due to the poor research activities in the past, and as a consequence of the recent war, the country remained one of the least explored in Europe in terms of dragonfly fauna.Although numerous papers with dragonfly records from the country have been published over the past 120 years, most of them include only small number of records or cover only a small portion of the investigated area.The earliest dragonfly records from the country originate from 1888, and can be found in the entomological collection of the National Museum of Bosnia and Herzegovina, where some of the first specimens from the Balkan Peninsula are kept (Kulijer & Marinov 2010).This collection is the most significant source of information on dragonflies of Bosnia and Herzegovina from the past.More than 60 years ago, the old Odonata collection of the National Museum of Bosnia and Herzegovina was reviewed by Adamović (1948), who reported 45 species for the country.In a brief overview of the dragonfly fauna of the former Yugoslav republics, Bedjanič & Bogdanović (2006) mention a total of 53 species for Bosnia and Herzegovina, while Boudot et al. (2009) listed 50 species for the country.Recently, Jović et al. (2010) compiled a list of 57 dragonfly species, based upon reviewing the literature and new faunistic data.Several papers, which contribute to the knowledge of the dragonfly fauna in the country, have also been published recently, including Bedjanič (2011) and Kulijer (2012).
The dragonfly studies in Bosnia and Herzegovina have recently been significantly intensified, and a great number of new records have become available.In 2009, a national survey and mapping of dragonfly distribution in the country was launched, and the dragonfly database of Bosnia and Herzegovina was created (Kulijer et al. 2013).The first comprehensive revision of Odonata in Bosnia and Herzegovina that includes all available data from literature, revision of museum collections, and a significant number of new, previously unpublished records is given by Kulijer et al. (2013).It includes records of 63 species for the country.
As the 2 nd European Congress on Odonatology (ECOO 2012) was held in Belgrade (Serbia) in the beginning of July 2012, it was an opportunity to investigate the dragonfly fauna of the Balkan Peninsula as well as to present richness of species and habitats of one of the most preserved and odonatologically least known regions of Europe.Two post congress excursions to Bosnia and Herzegovina and Macedonia were organized.In this article, we present and discuss results of the post congress excursion to Bosnia and Herzegovina made between 6 and 12 August 2012.

Study area
Our survey included all three biogeographical regions of the country.Northern Bosnia, bordering on the Sava River in the north, is a lowland region under the continental influence from Central Europe and Pannonian planes that stretch further to the north.In this area we visited two localities: one on the first (L 1) and one on the last day of the survey (L 36).At both locations, numerous gravel pits were found; some of them were largely overgrown by vegetation and hardly accessible, while others that are still in use were more or less without vegetation.At the last location we also inspected a small section of the Drina River in the border area to Serbia.
South Herzegovina region, influenced by the Mediterranean climate from the Adriatic Sea, with 55 known species, is the dragonfly richest region of the country (Kulijer et al. 2013).The most interesting habitats in this area are found in the lower part of the Neretva River basin.Our research focused on Hutovo Blato Nature Park and the Trebižat River Valley.Hutovo Blato (L 8-12) is one of the most important marshland areas of the country, and one of the most significant dragonfly areas.While traveling from the Neretva River Valley towards the mountain areas of East Bosnia, we also inspected several habitats at the Bregava River (L 24), Dabarsko polje (L 25) and Gatačko polje (L 26-27).Some of the most interesting habitats in central part of the country are glacial lakes, ponds and bogs in the high mountain zone above 1,400 m.These lakes host populations of several species, mainly of the northern European distribution which, in this area, are at the southern border of their distributions (Kulijer et al. 2013).On one of the last survey days we inspected some of these habitats in Zelengora Mts. in Sutjeska National Park, where most of these lakes are located.In Zelengora Mts., we inspected the Donje Bare and Gornje Bare Lakes, and forest habitats along the road and ponds near Gornje Bare Lake (L 28-32).While traveling through Central Bosnia, we also made few quick stops in order to investigate several habitats, mainly running water (L [33][34][35].

Material and methods
The Odonata were surveyed between 6 and 12 August 2012.The weather during the survey period was sunny, sometimes with high noon temperatures of over 35 o C, or 40 o C in the Mediterranean area.In general, the weather was very favourable for dragonflies, and mostly without rain or wind.
Mainly dragonfly adults were observed, while exuviae and larvae were searched for only sporadically.In total, we visited 36 localities (Fig. 1, Tab. 1): 26 in the Mediterranean region, 8 in the Alpine region, and 2 in the Continental region of the country.The division into three biogeographical regions is based on the map of the distribution of biogeographical regions in Europe (EEA 2005).
Our intention was to investigate as many different habitats as possible, but the short time of the excursion limited the research.The selection of localities was based on the possibility to find the most interesting species, and to present the diversity of species and habitats of the West Balkans and -with it -Bosnia and Herzegovina.Although we visited all three biographical regions of the country, the restricted time enabled detailed study only in the Mediterranean region.This region hosts some of the most interesting and most endangered taxa in the country.The region is characterized by rich and diverse freshwater habitats that are insufficiently researched.
All the records collected during this research have been entered into the national dragonfly database, and voucher specimens deposited in the collections of the National Museum of Bosnia and Herzegovina in Sarajevo.

Results
Altogether, we collected 357 records of 52 species from 36 localities.The list of recorded species with the locality data is presented in Table 2. Remarks on some interesting species are provided in the discussion section.

Discussion
During the six days of our survey, 52 species were found.Compared to 63 Odonata species reported for Bosnia and Herzegovina by Kulijer et al. (2013), our findings comprise 83% of all known dragonfly species in the country.
The commonest species were Platycnemis pennipes and Anax imperator, both found at 20 localities (56%).Orthetrum coerulescens was found at 19 localities (53%) and Ischnura elegans at 18 (50%).Seven species, i.e.Lestes virens, Coenagrion ornatum, Coenagrion scitulum, Aeshna mixta, Brachytron pratense, Somatochlora meridionalis, and Sympetrum meridionale, were observed at only one locality.We found 12 species in all three regions of the country.Although significant numbers of species were found during time-restricted research, the numbers of the recorded species and their abundance do not reflect the actual richness of the visited areas -especially in the Alpine and Continental parts of the country.As a consequence of short or early flight period, some of the species were either probably missed or under-recorded.Gomphus vulgatissimus is a common and abundant spring species in all regions of the country, and -although we visited several localities, where the species has been recorded in past years (Kulijer, unpublished data) -we failed to find a single specimen.Some other common spring species were also quite rare: P. nymphula was recorded at only two localities at higher altitudes, and B. pratense, common species in the Mediterranean area of the country, only at Deransko Lake, where a single female was observed.
For several nationally important species, i.e.Ceriagrion tenellum, Caliaeschna microstigma, Somatochlora metallica, Selysiothemis nigra, our observations add new localities and extend their known range in the country.

Notes on selected species
At the beginning of the 20 th century, Viktor Apfelbeck discovered a new form of Calopteryx in Herzegovina and named it Calopteryx balcanica.After inspecting the specimens collected by Apfelbeck, Fudakowski (1930) described this form as Calopteryx splendens balcanica.This taxon is known only from the Balkans, where it is present in coastal areas.In Bosnia and Herzegovina, rich populations are known from karst rivers of southern Herzegovina (Kulijer et al. 2013).We were lucky to observe C. s. ancilla and C. s. balcanica together and in great abundance in their typical habitat on the Neretva and Trebižat Rivers.

The distribution of closely related Chalcolestes parvidens and C. viridis in Bosnia and
Herzegovina is still insufficiently known.Recent field surveys and the revision of museum collections suggests that C. parvidens is much more common in the country (Kulijer et al. 2013).Our survey also supports this, as we found C. parvidens at two localities but none with C. viridis.
Until recently, Coenagrion ornatum was known only from the specimens stored in the collections of the National Museum in Sarajevo.Recent field surveys revealed that the species is much more common in the country, especially at richly vegetated streams and ditches in the poljes (Kulijer 2012, Kulijer et al. 2013, Kulijer unpublished data).During our survey, we found the species only at a single locality, which is most likely due to the type of visited habitats and the early flight period of the species.
Coenagrion hastulatum is one of the most interesting species found in Zelengora Mts.Bedjanič (2011) recorded the species for the first time in the country, at these lakes, a year before, in the end of June.Although the main flight period of the species usually finishes at the beginning of July, we managed to find several individuals -male and female -on Gornje Bare Lake, and a male specimen on Donje Bare Lake together with thousands of Enallagma cyathigerum, which made our spotting of C. hastulatum much more difficult.This makes the second report of the species on these lakes and in the country, confirming the presence of the local population.
The distribution of Ceriagrion tenellum in the western part of the Balkan Peninsula is mainly restricted to a narrow belt along the Adriatic coast (Boudot et al. 2009, Dijkstra & Lewington 2006, Kalkman 2005).In Bosnia and Herzegovina, this species is mainly known only from a small number of localities in the south (Kulijer et al. 2013).Recently, the species was also found at a small lake in central Bosnia (Kulijer, unpublished data).In Croatia, just near the border with Bosnia and Herzegovina, there are also some known populations (Bogdanović et al. 2008, Vinko 2011).During our survey, we observed the species at three localities -of which two are new for the species and first in the Trebižat River Valley.At L 3, several adults and two tandems were found at a small shallow pond fully overgrown by bushes and trees.The species was not observed at nearby stretches of the Trebižat River with richly developed vegetation along its banks.At L 16, adults and copula were found in the dense Carex vegetation along the Mlade River, and also on branches and leaves of bushes and trees that fully cover a small pond in the vicinity of the river.The pond is very similar to the one at L 3.
The European distribution of Caliaeschna microstigma is restricted to the Balkans (Boudot et al. 2009).In Bosnia and Herzegovina, the species occurs at the western border of its range.The species inhabits springs, fast flowing streams, and small rivers of the Herzegovina region (Kulijer et al. 2013).Our observations add new data to the knowledge of the species distribution in this area.In the Trebižat River Valley, the species was quite abundant, and often found together with Cordulegaster sp., especially the locally dominant C. heros.
One of the most interesting findings was the discovery of the population of Lindenia tetraphylla during the boat trip on Deransko Lake (Fig. 2) and along the Krupa River -both in Hutovo Blato Nature Park.L. tetraphylla was mentioned for the first time for the country by Bedjanič & Bogdanović (2006).All the previous records and the species status in the country were summarized and discussed by Kulijer et al. (2013).Our observations represent the first record of a strong population of this species in the country.Although only males were seen, the large number (at least 40 males at L 10, and 30 at L 11) and the territorial behaviour suggest that the species breeds in the area.The main number of individuals was observed patrolling over Deransko jezero, which is a shallow (about 0.5 m deep) muddy-bottom lake.Some club-rush and water lilies are growing in the central part, while the lake is surrounded by a vast area of dense reed beds, and fed by small cold streams and rivers from the nearby springs.The similar habitat of L. tetraphylla was reported in Turkey (Kalkman et al. 2004).Many of the observed individuals were of dark -dominantly black -form (Fig. 3), which is one of the characteristics of the population of L. tetraphylla in the Neretva area, regarded as separate, officially still undescribed species by Bogdanović (2006)   Two species of the genus Cordulegaster are present in Bosnia and Herzegovina.Although both can be found in most areas of the country, C. bidentata dominates in central, mountainous region, while C. heros prevails in the north and south (Kulijer et al. 2013).We mostly investigated Cordulegaster habitats in the Trebižat River Valley.C. heros was recorded at seven localities -all being karst springs (Fig. 4), while C. bidentata was found at two places.Both species, including exuviae, were found at Peč Mlini (L 20) (Fig. 5).At this locality, adults and exuviae of C. microstigma were also observed.Ovipositing of C. heros was observed downstream, while C. bidentata and C. microstigma were observed upstream.The distribution and status of the closely related Somatochlora metallica and S. meridionalis in the country is discussed by Kulijer et al. (2013).Up until our field trip, only one record of a single male S. metallica had been known from Donje Bare Lake, found in 2009 (Kulijer et al. 2013).During our investigation, numerous individuals, tandems and ovipositing females were observed at Donje Bare and Gornje Bare Lakes in Zelengora Mts.This was the second record and a new locality (Fig. 6) of the species for the country, and the first time that a population of the species was observed.On the other hand, although we found it at only one locality (L 4), S. meridionalis is much more common -during recent surveys it has been  present in this area -as already reported by Kulijer et al. (2013).The record of S. nigra at Krenica Lake (L 21) in northwest Herzegovina is the westernmost for the country.Quite unexpectedly, the species was also observed at our last locality, near Pavlović Bridge in North Bosnia (L 36).From a parked car, a male imago sitting on burned vegetation was observed by D. Vinko and M. Billqvist.Even though no picture was taken and no sampling was made, it was close enough to the car to be determined with certainty.While this species is typical of the Mediterranean coast (Boudot et al. 2009), it is not suspected to be found inland.A vagrant was found 245 kilometres from the coast, in the area that is separated from the coast by high mountains and without any river flowing to the south, which is a very strange site.The record from gravel pits near Pavlović Bridge (L 36) is so not only by far the northernmost for the country, but also an interesting and rare occurrence of this species this far inland.As the species is known as a strong migrant (Boudot et al. 2009), the records from a wider area of south Herzegovina are to be expected, while the occurrence of the species at Pavlović Bridge is most likely to be just a very rare observation of a vagrant individual.

Biogeographical and conservation perspective
From a biogeographical point of view, the Dinaric Alps are one of the most important refugia in southeastern Europe that harbour interesting disjunct relict populations of several boreal dragonfly species.These habitats are insufficiently explored and potentially threatened due to effects of climate change and increasing human activity.To date, the Zelengora Mts. are the only known locality in Bosnia and Herzegovina where Coenagrion hastulatum and Somatochlora metallica have been found.Additionally, numerous lakes and ponds in this area also host what are probably the most significant populations of Aeshna juncea and A. grandis in the country (Kulijer et al. 2013).We had luck with perfect weather at both locations, where rich dragonfly communities were observed; although the lack of time and the remoteness of the mountain lakes prevented us to visit more of these interesting localities.
Strong permanent populations of L. tetraphylla are rare in Europe (Boudot et al. 2009, Dijkstra & Lewington 2006, Schorr 1998).In Croatia, several populations have been reported by Belančić et al. (2008), with the closest population inhabiting the Neretva River delta.Further investigations are needed to determine whether permanent local population exists at Hutovo Blato.

Figure 6 .
Figure 6.Gornje Bare Lake (L 30) in Sutjeska National Park, the second discovered locality of Somatochlora metallica in Bosnia and Herzegovina (photo: D. Vinko).Slika 6. Jezero Gornje bare v Nacionalnem parku Sutjeska je za Bosno in Hercegovino druga znana lokaliteta kovinskega lesketnika (Somatochlora metallica) (foto: D. Vinko).The range of Selysiothemis nigra in Europe is restricted to the Mediterranean, where the scattered populations are mainly present in coastal areas (Boudot et al. 2009, Dijkstra & Lewington 2006).Our observations from Hutovo Blato confirm that the species is widely Records of C. ornatum, L. tetraphylla, and C. heros are especially interesting from the conservation point of view.These species are listed in the Annexes II and/or IV of the Habitats Directive.L. tetraphylla is also listed as Vulnerable (VU) in the European Red List of Odonata and C. ornatum, C. heros, C. bidentata, and C. microstigma as Near Threatened (NT) (Kalkman et al. 2010).In the Mediterranean region, C. heros is Vulnerable, and C. ornatum, B. pratense, C. microstigma, C. bidentata, L. tetraphylla, C. aenea, S. metallica are Near Threatened (Riservato et al. 2009).Additionally, several recorded species, i.e. C. hastulatum, C. tenellum, A. grandis, C. microstigma, S. metallica and S. nigra, are rare, or have restricted distribution in Bosnia and Herzegovina (Kulijer et al. 2013).

Table 2 .
Checklist of the Odonata species recorded during the post congress excursion of the 2 nd European Congress on Odonatology (ECOO 2012) to Bosnia and Herzegovina.The references for the locality where each species was observed are given.Species listed in Annexes II and/or IV of the Habitats Directive are printed in bold.Tabela 2. Seznam vrst kačjih pastirjev, najdenih v okviru pokongresne ekskurzije 2. evropskega odonatološkega kongresa (ECOO 2012) v Bosno in Hercegovino.Zapisu vrste je dodan seznam lokalitet, na katerih je bila vrsta najdena.Vrste, uvrščene v Prilogo II in/ali IV Habitatne direktive, so v krepkem tisku.