STUDY RESULTS OF THE PRESENCE OF Culicoides spp. IN SERBIA DURING 2017

During 2017, 784 insect samples were examined and the presence of Culicoides spp. was established in 25.51% of samples. Earlier research has found that the dominant population of Culicoides spp in Serbia belongs to Obsoletus complexes, established in 60.05% of analyzed samples. Out of the entire insect population analyzed, males were found in 22.84%, unpigmented (young) females in 67.97%, females who took blood in 7.39%, whereas 1.35% were gravid females. Culicoides spp. from the Pulicaris complex was established in 38.85% of examined samples. Males were found in 18.91%, unpigmented (young) females in 71.72%, females who took blood in 9.09%, and 1.11% were gravid females. Other types of culicoids have been established in less than 10% of the examined samples. During examination, the most prevalent species were Culicoides obsoletus, C. picturalis, C. lupicaris, C. scoticus and C. fascipennis.


INTRODUCTION
Entomofauna of Serbia is rich and diverse. Among this abundance of arthropods and insects, some species were not a topic of interest of the experts since they did not stand out as potential vectors, or simply did not come to the point that experts were dealing with them (Krunić, 1986). This was the case with the family of Ceratopogonidae, which belongs to the family Culicodina. Insects of the genus Culicoides spp. have not been studied in Serbia, so there were contradictory opinions about their persistence in our area (Pavlović et al., 2002). Only with the outbreak of bluetongue disease in 2006, the study of this kind of insects became important and the first research was started in order to determine the presence and extent of these insects (Pavlović et al., 2002). The research carried out during 2006-2007 confirmed their presence throughout the territory of Serbia. Research in the period 2011-2012 was focused on the study of Cullicoides species that are present in Serbia (Pavlović et al., 2009). Finally, in 2014, the re-emergence of bluetongue disease emphasized the need for continuous control of the presence of these insects (Maksimović Zorić et al., 2016). Since then, continuous annual monitoring of these insects has been conducted that gave an insight into their seasonal dynamics as well as the most dominant species (Pavlović et al., 2014;2016a;2016b;2017). In that period, a total of 784 entomological check-ups were made. Culicoides spp. samples were collected from all epizootic areas in Serbia. Determination of Culicoides spp insects was made by morphometric method recommended by the Italian National Reference Centre for Exotic Diseases (National Reference Centre for the study of Exotic Animal Diseases (CESME)) and OIE Reference Laboratory for Bluetongue Istituto Sperimentale Zooprofilattico dell' Abruzzo e del Molise "G. Caporale" (IZSAM) from Teramo, Italy. Species definition of Culicoides spp. has traditionally been based on the morphology of adult insects (Goffredo and Meiswinkel, 2004). Adult individuals of Culicoides spp. are notable for their characteristic wing pigmentation pattern and distribution of wing microtrichia, which in certain species can be used as the principle diagnostic feature. In practice, however, the requirement is that specimens should be slide mounted, image-captured, measured and analysed, which is time consuming and therefore the use of morphometries for identification purposes in high-throughput systems such as surveillance programs is recommended (Weeks et al., 1999;Mathieu et al., 2012).

RESULTS
Of the total number of insect samples, the presence of Culicoides spp. was established in 25.51% (200/784).
In the epizootic area of Belgrade, Culicoides spp. was found in 24.39% Earlier research has found that the dominant population of Culicoides spp in Serbia belongs to Obsoletus complexes, which was established in 60.05% of samples. Males were found in 22.84% samples, non-pigmented (young) females in 67.97%, females taking the blood at 7.39%, while 1.35% were pregnant females.
Culicoides spp. from Pulicaris complexes were found in 38.85% samples. Among tested samples, males were found in 18.91% samples, non-pigmented (young) females in 71.72%, females who took blood in 9.09% and 1.11% were pregnant females.
Other types of Culicoides are set up in less than 10% of the examined samples.

DISCUSION
During the previous examinations, 22 species of Culicoides were found and the following species were dominant in 2017: Culicoides obsoletus, C. picturalis, C. lupicaris, C. scoticus and C. fascipennis. As compared with the period 2015-2016, a change in a faunistic sense since the dominant species in the previous period included C. obsoletus, C. pulicaris, C. parrots and C. nubeculosus (Pavlović et al., 2017).
Increasing spread of Culicides, the emergence of new genera in some areas and the large number of these insects is a consequence of climate change. In the last century, the mean air temperature in the world increased by 0. Culicoides's seasonal dynamic is directly correlated with temperature and humidity. Culicoides from both groups -Obsoletus and Pulicaris complex, were reaching maximum abundance in spring and autumn, which is normal for this species (Conte et  Culicoides are also subjected to molecular assays (RT-PCR) to analyze the presence of blue tongue viral genome. The genome of blue tongue disease virus was identified in one sample from the territory of the Mionica municipality in September 2016, which is an expected finding considering the outbreak of this disease just in the month of September.

CONCLUSION
During 2017, a total of 784 entomological check-ups were made. Of the total number of insect samples, the presence of Culicoides spp. was established in 25.51% (200/784). During the examination period, there was a change in view of dominant species of Culicoides species. In our examination dated 2017, the dominant species were Culicoides obsoletus, C. picturalis, C. lupicaris, C. scoticus and C. fascipennis. As compared with the period 2015-2016 there was a change in the faunistic sense, that is, the dominant species in the previous period were C. obsoletus, C. pulicaris, C. parrots and C. nubeculosus. This was influenced by microclimatic and other biotic factors.