Syrphidae, Diptera) in Basic Types of Agroecosystems in Karlovo Valley (Bulgaria) 49
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Syrphid Communities (Syrphidae, Diptera) in Basic Types of Agroecosystems in Karlovo Valley (Bulgaria) 49 Bulgarian Journal of Agricultural Science, 17 (No 1) 2011, 49-54 Agricultural Academy SYRPHID COMMUNITIES (SYRPHIDAE, DIPTERA) IN BASIC TYPES OF AGROECOSYSTEMS IN KARLOVO VALLEY (BULGARIA) E. MARKOVA and T. TEOFILOVA Sofia University ”St. Kliment Ohridski”, Department of Ecology and Environmental Protection, Faculty of Biology, 8, Dragan Tsankov Blvd., BG - 1164 Sofia , Bulgaria Abstract MARKOVA, Emilia and Teodora TEOFILOVA, 2011. Syrphid communities (Syrphidae, Diptera) in basic types of agroecosystems in Karlovo valley (Bulgaria). Bulg. J. Agric. Sci., 17: 49-54 This contribution is the first ecologicaly-faunistic study of the syrphid flies from Karlovo valley. Syrphid cenoses in two basic types of agroecosystems were examined – cereals with merged surface and maize. Fourteen agroecosystems were explored. Main population and cenotic parameters of the syrphid communities were iden- tified and analysed: species composition, evaluated qualitatively and quantitatively; occurrence of the species; population density; general average density; dominant and ecological structure. The study established 14 species syrphid flies. All species were new for the syrphid fauna of the valley. Key words: syrphid flies, Syrphidae, Karlovo valley, community, biological control Introduction as degree of occurrence, density of populations, set of dominants and trophy specialization of the Flies from the family Syrphidae are a major species. group bioregulators of the density of a large This study is the first ecologically-faunistic number of pests in agriculture and forestry. The investigation of the syrphid flies in the Karlovo density of predatory syrphid flies increases in di- valley area. Its purpose is to contribute to the rect proportion with the increasing of the number replenishment of the database, determining the of the pest. At small density of the pest, they fully actual status of this important for the functioning suppress it, and at its high density, they maintain of ecosystems group insects in Bulgaria and hence it below the threshold of economic harm (Adash- to its sterling use for the purposes of the biological kevich, 1975). These characteristics define them as and integrated pest control. extremely promising bio-agents in the fight against the organisms harmful to plants. Material and Methods The use of syrphid flies is impossible without an inventory of the resources available, without a During the investigation were examined 14 thorough knowledge of the species composition agroecosystems, of which 7 sown with cereals with and number of ecological characteristics, such merged surface (4 with wheat and 3 with rye) and 7 E-mail: [email protected] 50 E. Markova and T. Teofilova sown with maize. Wheat ecosystems were situated The established species and their density in the near Klisura, Karlovo, Vasil Levski and Domlyan different ecosystems were presented in Tables 1 and ecosystems with rye – near Stoletovo, Kara- and 2 velovo and Voynyagovo. Maize ecosystems were Species composition in the two examined types near Klisura, Stoletovo, Karavelovo, Voynyagovo, of agro-ecosystems differed in the number of their Karlovo, Vasil Levski and Domlyan. components. In the cereals with merged surface The material of syrphid flies was collected in a were established 12 syrphid flies and in the maize way allowing qualitative and quantitative assess- ecosystems the number of the found species was ment. The method of “mowing” was used, with double less – 6 species. a standard entomological sack with a diameter of Within the cereal ecosystems with most species 30 cm. The material collection was carried out in was distinguished the wheat near Domlyan – 7 dry and quiet weather before noon. Ten samples of species found, and most impoverished was the each ecosystem in each gathering were taken. The wheat ecosystem near Karlovo – only 4 species. number of swathes in each sample was 50, and the Ecosystems with rye near Stoletovo, Karavelovo, average length of the swath was 1 m. Only adult Voynyagovo and the ecosystem with wheat near stages of syrphid flies were reported. Vasil Levski had 6 species each and those with For determination of the taxonomic similarity wheat near Klisura had 5 species. between the faunistic complexes in the different Among the tested maize ecosystems richest ecosystems and between the complexes of main in species (6 species) was the ecosystem near species was used the coefficient of Jaccard (Wall- Voynyagovo, and with least species number (3 work, 1976) and the degree of proximity between species) - the ecosystem near Klisura. Five syrphid the complexes was assessed by Zlotin (1975). The species were found in the maize ecosystems near similarity in population density was determined Stoletovo and Domlyan, and 4 - in the ecosystems by the coefficient of Jaccard-Naumov (Chernov, near Karavelovo, Karlovo and Vasil Levski. 1975). Dominant structure of the communities Syrfid complexes in the studied ecosystems was established in 4-grades classification of Arza- varied not only by the number of their forming masov, Dolbik, Hotko and Shevtsova (Hotko et al., components, but also by qualitative composition. 1982), and the species occurrence – in 3-grades Taxonomic similarity between the species spectra classification of Bodenheimer and Balogh (Dazho, of the two types agroecosystems was low – 29 %, 1975). The population density was calculated by which illustrated the major qualitatively disparity the method of Gilyarov (1974), and the data on between them. Taxonomic difference between the average density were statistically processed syrfid complexes also underlined in comparing and were shown for 1 ha. the species complexes within the limits of the same type of crop. The differences between the Results and Discussion species composition in the various points of cere- als with merged surface in most of the cases (11 Species composition cases) were too large. The largest difference was During the investigation 14 species syrphid flies observed between the ecosystems with rye near belonging to 6 genera from subfam. Syrphinae and Stoletovo and Voynyagovo (taxonomic similarity 2 genera from subfam. Milesiinae were established between species spectra was only 20 %). In 6 of (Peck, 1988). the cases similarity was medium, and it was high All identified by the survey species were com- in 4 of the cases. Qualitatively closest to each municated for the first time for the syrphid fauna other were the ecosystems with rye near Voynya- of Karlovo valley. govo and the one with wheat near Domlyan and Syrphid Communities (Syrphidae, Diptera) in Basic Types of Agroecosystems in Karlovo Valley (Bulgaria) 51 Table 1 Species composition and numbers (number individuals.ha-1) of the syrphid flies in the investigated cereals with a merged surface Klisura Stoletovo Karavelovo Voynyagovo Karlovo Vasil Levski Domlyan Species 2 29 2 29 2 29 2 29 2 29 2 29 2 29 June July June July June July June July June July June July June July Episyrphus 67 67 133 67 133 67 133 67 133 balteatus (Deg.) Metasyrphus 67 133 67 200 67 133 67 67 corollae (Fabr.) Sphaerophoria 67 67 menthastri (L.) S. rueppelli 67 (Wied.) S. scripta (L.) 67 67 200 67 333 133 200 200 67 133 133 200 Syrphus 67 vitripennis Mg. Melanostoma 67 133 67 133 133 mellinum (L.) Paragus 67 67 200 tibialis (Fall.) Eristalis 67 133 133 67 arbustorum (L.) E. nemorum (L.) 67 67 133 E. tenax (L.) 67 133 67 67 133 67 133 Syritta 200 67 200 200 67 133 pipiens (L.) also the wheat ecosystems near Vasil Levski and Average qualitative proximity was determined in Domlyan (with taxonomic proximity 63 %). High 3 of the cases, and the taxonomic proximity was similarity was found also between the wheat eco- high in most of the cases – 17. Qualitatively clos- system near Klisura and the ecosystem with rye est were the ecosystems with maize near Stoletovo near Stoletovo, and between the ecosystems with and Voynyagovo and those near Voynyagovo and wheat near Klisura and Vasil Levski (taxonomic Domlyan (taxonomic affinity between them – 83 affinity 57 %). %). The situation in ecosystems with maize was In conducted examination the impression was rather different. In only one of the cases the taxo- that the more abundant species composition of nomic similarity was low – between ecosystems syrphid flies in cereals with merged surface in near Vasil Levski and Karlovo (taxonomic similar- Karlovo valley (12 species), compared with those ity was only 10 %). The other maize ecosystems in the neighboring Zlatitsa-Pirdop (8 species) and were closer in terms of their species composition. Kazanlak (6 species) valleys (Markova, Tsonev, 52 E. Markova and T. Teofilova Table 2 Species composition and numbers (number individuals.ha-1) in the investigated ecosystems with maize Klisura Stoletovo Karavelovo Voynaygovo Karlovo Vasil Levski Domlayn Species 3 30 3 30 3 30 3 30 4 31 4 31 4 31 June July June July June July June July June July June July June July Episyrphus 67 133 67 67 200 67 267 67 67 67 67 200 balteatus (Deg.) Metasyrphus 67 67 133 67 200 67 133 133 corollae (Fabr.) M. luniger (Mg.) 133 67 Sphaerophoria 67 67 133 133 67 67 67 67 philanthus (Mg.) S. scripta (L.) 67 133 67 133 133 133 200 133 133 67 200 200 Syritta pipiens (L.) 200 67 67 1993; Markova, 2003). Taxonomic similarity Population density between species spectra in the wheat ecosystems The density of syrphid flies in both examined of the Zlatitsa-Pirdop and Karlovo valleys was 54 types of agroecosystems was not the same. The %, i.e. average. The taxonomic composition in the general average density in the ecosystems with wheat ecosystem in Kazanlak valley, however, was cereals was 490 ± 46 ind.ha-1. In the ecosystems quite different from the one found in the wheat and with maize density was 357 ± 37 ind.ha-1, i. e. 1.4 rye ecosystems in Karlovo valley. The similarity times lower than in the cereals.