CONTRIBUTION TO THE KNOWLEDGE OF ORTHOPTERA ON BELASITSA MOUNTAIN, SOUTH-EAST MACEDONIA

First records about Orthopteran fauna of Macedonia were reported by Doflein [1], Berland & Chopard [2] and Burr et al. [3]. Most of the records, however, concern the present territory of Greece (see Chobanov & Mihajlova [4]). Later on, Ramme [5–10] and Us [11] added a significant amount of data including new species for the science described by Ramme (see the latter citations). A second period of active studies on the fauna and, partly, taxonomy of the group in Macedonia refers to the work of Karaman (e.g., Karaman [12–22]; for a full list of references see Chobanov & Mihajlova [4]). Us & Matvejev [23] made an attempt to synthesize all previous data, though several synonymous taxa were considered with repetitive information or former records for the present territory of Greece were included. Local faunistic contributions were published by Dimovski [24, 25] and single records of Orthoptera are fragmentary available in the literature (see Chobanov & Mihajlova [4]). The third period of studies started in the 2000s. Local faunistic information has been reported by Chobanov [26] and Micevski et al. [27] and the to-date information on Orthoptera of Macedonia has been critically summarized by Chobanov & Mihajlova [4]. In addition, three new species have been described from the territory of this country by Chobanov & Heller [28], Karaman et al. [29] and Chobanov et al. [30], some faunistic records were added by Lemonnier-Darcemont [31], Chobanov et al. [32] and a “Red list of Orthoptera of the Republic of Macedonia” was published by LemonnierDarcemont et al. [33]. Thus, currently the number of recognized species for Macedonia is 171 (with two additional subspecies). The aim of the present study is to obtain some basic knowledge of the Orthoptera fauna of the northern part of Belasitsa Mountain. Although the Orthopteran fauna of Belasitsa was thoroughly studied on the territory of Bulgaria (e.g., [34, 35]), presently there are no records from the Macedonian part of this area. In addition we present the records of Orthoptera from Belasitsa Mountain collected in the period April–November 2010.


INTRODUCTION
First records about Orthopteran fauna of Macedonia were reported by Doflein [1], Berland & Chopard [2] and Burr et al. [3]. Most of the records, however, concern the present territory of Greece (see Chobanov & Mihajlova [4]). Later on, Ramme [5][6][7][8][9][10] and Us [11] added a significant amount of data including new species for the science described by Ramme (see the latter citations). A second period of active studies on the fauna and, partly, taxonomy of the group in Macedonia refers to the work of Karaman (e.g., Karaman [12][13][14][15][16][17][18][19][20][21][22]; for a full list of references see Chobanov & Mihajlova [4]). Us & Matvejev [23] made an attempt to synthesize all previous data, though several synonymous taxa were considered with repetitive information or former records for the present territory of Greece were included. Local faunistic contributions were published by Dimovski [24,25] and single records of Orthoptera are fragmentary available in the literature (see Chobanov & Mihajlova [4]). The third period of studies started in the 2000s. Local faunistic information has been reported by Chobanov [26] and Micevski et al. [27] and the to-date information on Orthoptera of Macedonia has been critically summarized by Chobanov & Mihajlova [4]. In addition, three new species have been described from the territory of this country by Chobanov & Heller [28], Karaman et al. [29] and Chobanov et al. [30], some faunistic records were added by Lemonnier-Darcemont [31], Chobanov et al. [32] and a "Red list of Orthoptera of the Republic of Macedonia" was published by Lemonnier-Darcemont et al. [33]. Thus, currently the number of recognized species for Macedonia is 171 (with two additional subspecies).
The aim of the present study is to obtain some basic knowledge of the Orthoptera fauna of the northern part of Belasitsa Mountain. Although the Orthopteran fauna of Belasitsa was thoroughly studied on the territory of Bulgaria (e.g., [34,35]), presently there are no records from the Macedonian part of this area. In addition we present the records of Orthoptera from Belasitsa Mountain collected in the period April-November 2010.

AREA OF RESEARCH
Belasitsa Mountain is situated in the southeastern part of Macedonia, bounded between Bulgaria and Greece (Figure 1a). It is among the smallest by area mountains in Macedonia. From the neighbouring mountains Belasitsa is separated with the river valleys of Vardar in the west, Struma in the east, Strumicka in the north and Dojranska and Serska in the south. According to the altitude, it belongs to the group of high mountains (over 2000 m) [36]. The highest peak is Radomir (Kalabak) -2029 m at the border between Bulgaria and Greece. The highest peak on the territory of Macedonia is Tumba (1881 m), located at the border with the neighbouring countries Greece and Bulgaria. In the central part of the mountain (within Macedonia) the peak Visoka Chuka (1845 m) dominates, and in the eastern partthe peak Samer (1877 m).
From the structural-geological point of view, Belasitsa is a typical linear horst. It was formed as a mountain block during Pliocene between two parallel seedlings bounded in the north and in the south, rising as a horst between two sinking anticlinoria.
The mountain is built mainly out of metamorphic rocksamphibolites, different types of minerals, granite, gneiss, etc. The oldest are gneissmetamorphic rocks from the crystalline slates group of archaic age.
The low parts of the mountain are characterized by cimet-forest soils, and in the higher parts the brown-forest and mountain-meadow soils are most common. The belt between 600 and 1800 m is characterized by brown-forest soils.
The climate in the low-mountain belt (300-1000 m) is mountain continental with Mediterranean influence, while the mountain belt over 1000 m alt. is influenced by the cold continental climate [37].
The samples were collected using pitfall traps, representing a plastic cup with a volume of 0,5 liter. In total 140 traps were placed in 14 different localities referring to different altitudes on Belasitsa Mountain. At each locality 10 pitfall traps were placed along a transect line following the isohypse. The traps were 10 m apart in order to avoid possible interference between them. The upper edge of the trap was placed parallel to the soil surface. Formaldehyde-vinegar solution (1:7; 200 ml) was used as a preservative.

RESULTS AND DISCUSSION
As a result of the present study, 16 species of Orthopterans belonging to 6 families, 9 subfamilies and 16 genera were sampled. This number represents 22% of the species found in the Bulgarian part of the mountain and 9% of the species currently recorded from Macedonia. Therefore, our findings represent only a minor part of the taxa that are expected to occur in the Macedonian part of Belasitsa Mountain. The low number of taxa may be explained with a combination of factors: (1) the sampling has been conducted almost exclusively in forested habitats that are inhabited by a low number of orthopterans; (2) using a very specific collecting technique (soil traps) additionally may restrict the collecting success, avoiding the sampling of highly mobile species; (3) collecting has been performed on a single altitudinal line at the northern slope of the mountain. Thus, the present study is only an initial step for further complete investigations of the Orthopteran fauna of Belasitsa. Combining different collecting approaches in all plant associations of the mountain (including its southern slope with a well expressed Mediterranean climate influence) the number of species of Orthoptera is expected to reach at least 80. Distribution: The species is currently recorded from Italy, the western and southern Balkans and Asia Minor.
Distribution in Macedonia: One of the most widely distributed species in Macedonia occurring in diverse (mostly xeromorphic) habitats from the lowlands to the highest mountain summits.

CONCLUSION
This paper represents taxa that are expected to occur in the Macedonian part of Belasitsa Mountain and provides additional information on the occurrence of Orthoptera fauna. However, further studies are necessarily to improve our knowledge of Orthopteran fauna on Belasitsa Mountain as part of a higher biodiversity region.