Cent. Eur. J. Biol. • 7(5) • 2012 • 917-926 DOI: 10.2478/s11535-012-0061-0 Central European Journal of Biology Mosquitoes (Diptera, Culicidae) of the Morava River floodplain, Slovakia Research Article Lucia Strelková*, Jozef Halgoš Department of Ecology, Faculty of Natural Sciences Comenius University, 842 15 Bratislava 4, Slovakia Received 07 February 2012; Accepted 15 May 2012 Abstract: Research on the Morava River floodplain mosquito fauna was carried out from April to October in 2009 and 2010. Altogether, 5864 adults were collected and identified from 12 selected sites. The presence of 28 mosquito species belonging to6 genera were confirmed in the study area. The floodplain of the Morava River is known for its frequent inundationevery year. The floods are quite irregular and often followed by the mass production of mosquitoes. The most abundant species were Aedes vexans (41.4%), Ae. cinereus (7.5%), Ae. rossicus (16.7%), Ochlerotatus sticticus (20.5%), and Culex pipiens (3.1%). Ae. vexans and Oc. sticticus are typical outbreak species for the Morava River floodplain. The years 2009 and 2010 differed in the number of floods, which influenced the mosquito faunal composition and abundance during theyear. Keywords: Mosquitoes • Morava River Basin • Seasonal changes • Floods • Floodplain ©VersitaSp.zo.o. 1. Introduction There are 50 mosquito species recorded in Slovakia. More attention started to be paid to the family Culicidae Spreading of diseases across Europe in the last several at the beginning of the 20th century due to the occurrence years has led to the necessity of mosquito monitoring. of malaria in Slovakia, which was eradicated in 1963 [2]. Tropical mosquito-borne diseases like dengue, Mosquitoes transmitted or still transmit four arboviruses: chikungunya, and West Nile fever have rapidly become Ťahyňa, Čalovo, Sindbis, and West Nile [3], in the territory a threat to public health in Europe that is proving difficult of Slovakia. West Nile virus was reported in humans from to confront. The presence and spread of these types several countries in Central and Eastern Europe and the of diseases depend on many different and interacting Mediterranean last year, and 2010 saw the highest number factors, such as the current distribution of mosquitoes of human cases reported, suggesting it has become a re- and their population densities, climate, wind patterns, emerging pathogen in Europe [4] (http://archive.defra.gov. proximity to bodies of water, land use, and vegetation. uk/foodfarm/farmanimal/diseases/monitoring/documents/ In addition, the frequency of intercontinental travel wnv-europe.pdf). Another mosquito-borne disease in and trade and global warming allow foreign species Slovakia is dirofilariosis. The first autochthonous case in to establish themselves in new environments, where Slovakia was recorded in dogs in 2005, and first human their natural enemies are not found. In the recent past, case occurred in 2007 in Western Slovakia [5], the area considerable fluctuation in air temperature has been where our research was carried out. At present, dirofilariosis typical for spring and summer. Precipitation has been is regarded as the fastest-spreading arthropod-borne irregularly spread during the year, in contrast with disease, and represents a high infection risk for both normal conditions featuring long dry periods alternating animals and humans [6]. with heavy rains, which caused localised or extensive The Morava River floodplain, with various types floods with mosquito calamities [1]. of stagnant waters, offers suitable conditions for * E-mail: [email protected] 917 Mosquitoes (Diptera, Culicidae) of the Morava River floodplain, Slovakia mosquito hatching. Variation in climatic conditions can Devín Castle near the town of Bratislava to the village of lead to noticeable changes taking place in freshwater Moravský Svätý Ján. The study sites represent different ecosystems, which are particularly evident in the types of stagnant waters (including plesiopotamal, species composition and ecology of the examined palaeopotamal, breeding sites in forests and on animal groups [7]. The key factors that influence meadows, and temporary ponds created and filled by composition, abundance, and ecology of mosquito rainfall or groundwater). Selected characteristics of the species are changes in the hydrological regime and 12 study sites are summarized in Table 1. water and air temperatures. The Morava River floodplain Material was collected at least once a month from is characterized by its frequent and often irregular floods April to October, depending on floods. Some of the every year. These floods create ideal breeding habitats study sites were not always accessible due to flooding. for floodwater species of mosquitoes of the genera Adults were collected by sweeping the vegetation with Aedes and Ochlerotatus. The years 2009 and 2010 entomological nets (diameter 25 cm) for 10 minutes at differed in the number and frequency of flood events. each breeding site. Collection began in the early morning Changes in climatic conditions lead to changes in the at site 1 and continued over all sites in one day. Water phenology of mosquitoes [7]. Earlier snow melt and temperature was also measured at breeding sites. The spring precipitation could result in a shift in the larval collected mosquitoes were killed by ether, transported development of the spring monovoltine species [7]. The to the laboratory, and stored in the freezer. Sex was mosquito production can be influenced by the extent determined using a stereomicroscope. All males were of flooding and previous precipitation, and the final dissected and external genitalia were mounted in mosquito assemblage depends on the local hydrological Canada balsam. Morphological identification keys were conditions [8]. used for species identification [10,11]. We used PAST software version 1.95 (http://folk.uio.no/ ohammer/past/) to evaluate the data for site similarity based 2. Experimental Procedures on the presence/absence of species (Jaccard index). The Morava River floodplain is one of the last well- preserved wetlands in Central Europe [9]. Collections 3. Results of mosquitoes were made at 12 selected sites in the Morava River floodplain (Figure 1) from April to October Years 2009 and 2010 were very similar when considering in 2009 and 2010. The study area extends from the the mean monthly air temperature (Figure 2). The Figure 1. Locations of collection sites in the Morava River floodplain, Slovakia (source: www.maps.google.com). 918 L. Strelková, J. Halgoš Altitude (m Depth Shading Sediment Site Latitude (N) Longitude (E) Biotope Ambience above sea level) (m) (%) type 1. Moravský Sv. Ján - before 48°36’01,4’’ 16°56’39,9’’ 83.3 SP 0.4 W, M 20 earth embankment 2. Moravský Sv. Ján - behind 48°36’01,4’’ 16°56’39,9’’ 83.3 D 0.4 W 100 mud embankment 3. Lantov - tributary 48°34’10,5’’ 16°57’16,0’’ 150.6 Pal 1 M 40 mud 4. Lantov - meadow 48°34’10,5’’ 16°57’16,0’’ 150.6 Moor 0.7 M 0 mud 5. Malé Leváre a 48°33’15,2’’ 16°57’38,0’’ 140 D 0.5 W 100 mud 6. Malé Leváre b 48°30’50,6’’ 16°56’00,4’’ 112 D 0.4 W 100 mud 7. Vysoká pri Morave 48°19’14,8’’ 16°54’29,8’’ 137 Ple 0.5 S,M 75 mud 8. Devínske jazero - meadow 48°16’23,4’’ 16°55’46,1’’ 136.1 Ple 0.2 M 10 mud 9. Devínske jazero - forest 48°16’18,9’’ 16°55’52,0’’ 131 D 0.6 W 100 earth 10. Devínske jazero - tributary 48°15’42,2’’ 16°57’30,9’’ 123.6 Ple 0.5 M 10 mud 11. Devínska Nová Ves - 48°19’49,0’’ 16°97’40,4’’ 124 D 0.2 W 100 earth alluvial forest 12. Devín - near the castle 48°10’33,4’’ 16°58’40,1’’ 124 SD 0.8 W, M 50 mud Table 1. Characteristics of the study sites. Abbreviations: D = depression filled by groundwater, SP = pool filled with water in spring only, Ple = plesiopotamal, Pal = palaeopotamal, W = wood, M = meadow, S = suburban area. Figure 2. Mean monthly air temperature and precipitation in Moravský Svätý Ján (data from Slovak Hydrometeorological Institute in Bratislava). greatest differences occurred in April (14.4°C in 2009 lasted from May to September, with the highest values and 10.4°C in 2010) and September (16.5°C in 2009 in May and August. and 13.9°C in 2010). The other months differed by no A total of 5864 adult mosquitoes belonging to 28 more than 2°C. The years 2009 and 2010 differed in the species were collected (Table 2). A total of 3205 adults water level and precipitation values throughout the year were collected in 2009. The months with the highest (Figures 2 and 3). While the floods in 2009 occurred in abundance were July and August. The most abundant the spring and summer months only, the year 2010 was species were Ae. vexans, Oc. sticticus, Ae. rossicus, atypical with respect to the frequency and duration of and Ae. cinereus (Table 3), together representing over floods. The water level of the Morava River reached its 85% of all specimens collected. There was only one highest values in March, May and June, but Figure 3 peak of abundance of all species sampled in 2009, shows that raised water levels occurred many times although there were several generations of some throughout the year. In 2009, higher rates of precipitation species (Figure 4). A total of 2659 adult mosquitoes were lasted from February until March, from May until August, collected in 2010. The most abundant species were Ae. and in November. In 2010, high mean precipitation vexans, Oc. sticticus, Ae. rossicus, and Cx. pipiens 919 Mosquitoes (Diptera, Culicidae) of the Morava River floodplain, Slovakia Figure 3. Daily water level values of the Morava River in Moravský Svätý Ján in 2009 and 2010 (data from the Slovak Hydrometeorological Institute, Bratislava).