Silva Balcanica, 16(1)/2015 NEW RECORDS OF DOLICHOPODIDAE (DIPTERA) FOR BULGARIA. COMPARISON OF DOLICHOPODID DIVERSITY ON RIVER BANKS AND IN SOME FORESTS OF THE UPPER THRACIAN PLAIN Mihail Kechev 1, 2, Mariyana Ivanova1 1 University of Agribusiness and Rural Development – Plovdiv 2 Bulgarian Scientific Selection-Technical Union – Plovdiv Abstract The paper gives information about 35 dolichopodid flies collected in a small woodland and aquatic site situated in the Upper Thracian Plain (Bulgaria). Ac- cording to the abundance in the investigated ecosystem samples are divided in five groups: eudominant – Poecilobothrus regalis (54.17%), dominant – Hercostomus thraciensis (13.38%), subdominant – Hercostomus plagiatus (8.52%), rare – 8 spe- cies (1 – 5%), subrare – 24 species (<1%). Four of the species (Chrysotus femoratus, Hercostomus plagiatus, Rhaphium pectinatum and Lamprochromus bifasciatus) are newly recorded to the fauna of Bulgaria. Diversity and similarity indices are calcu- lated and comparisons are made of the studied site with two other sites from which dolichopodid flies are collected and investigated before. Key words: Bulgaria, Diptera, Dolichopodidae, new records, diversity index, similarity index INTRODUCTION Family Dolichopodidae, often called long-legged flies, encompasses small to medium sized (1-10 mm) mostly predatory flies. The World dolichopodid fauna is presented with about 7000 species and 240 genera (Yang et al., 2006, Grichanov, 2007). One of the main factors for its distribution is humidity and the flies of this family are aquatic and semi-aquatic inhabitants that can be found in the vegetation around lakes, ponds, marshes, rivers and brooks. The dolichopodid fauna of Bulgaria is known with 169 published species (Ke- chev, 2011, Kechev et al., 2014 and Kechev, Negrobov, 2015) up to now. In Bulgaria investigations of these flies on ecosystem level are scarce. The main purposes of this work are to collect dolichopodid flies from a site situated in the Upper Thracian Plain, to describe collected samples and present di- versity and similarity with two other sites previously being examined. This is just a 87 pilot examination showing the need of investigations on ecosystem level searching for the reasons of diversities and similarities and explaining geographical and sea- sonal distribution of dolichopodid on a scientific basis. STUDIED AREA The investigated site (Fig. 1, 2 and 3), called Basha, is situated in the Upper Thracian Plain, 3 km southwest of the town of Chirpan (Bulgaria). Geographical coordinates – 42°10’39”N, 25°17’58”E, 149 m a. s. l. The sampling site represents a small pond (fig. 3), overgrown by different hygrophilous plants. The size of the pond is about 30 m length and 20 m width, depth – 1-1.5 m. The entire site is surrounded by agricultural lands, only a small stream flows on the south of it. The trees are presented by Populus sp., Salix fragillis L., Salix triandra L., Juglans regia L., Sambucus nigra L., Morus alba L., Ailanthus altissima (Mill.) Swingle. The most dominant shrubs and grasses are presented by Urtica dioica L., Mentha aquatica L., Arctium lappa L., Aristolochia clematitis L., Conium macula- tum L., Cirsium vulgare (Savi) Ten., Rosa canina L., Rubus ceasius L., Cardamine sp. The plant species in the water are Typha latifolia L., Carex sp., Berula erecta (Huds.) Coville. Most common vertebrate species in this place are marsh frog – Rana ridibun- da (Pallas, 1771) and European pond turtle – Emys orbicularis (Linnaeus, 1758). Material AND METHODS The material for the present work was collected by sweeping in the period from May 2013 to April 2014 (24 collecting trips from 2 May 2013 to 21 April 2014). The studied site was visited three times per month and insects were collected for 1 h per trip (from 5 to 6 p.m.). Adults collected in the field were put in vials con- Fig. 1-3. Studied area: 1. Map of Bulgaria with an indication of investigated area; 2. Google Earth map of the site; 3. Picture of the studied site. 88 taining 75% ethanol. The specimens were sorted in the laboratory with a binocular microscope. The faunistic list gives the following information: date of collecting, number of collected specimens per date (males and females), name of collector and distribution. One species is given with its generic name (Medetera sp.), because only female was collected. However, without male in one sample, the determination is difficult. Studies of Negrobov (1991), Pollet (2004) and Grichanov (2007) are used for species’ distribution. Google Earth software (version 7.1.1.1888) was used for Fig. 2, geographical coordinates and altitude. The dominance structure is evaluated according to Heydemann’s classifica- tion of five degrees of dominance: eudominant species (>30% of all collected speci- mens), dominant (10-0%), subdominant (5-10%), rare (1-5%), subrare (<1%). The study evaluates biodiversity considering the following measures: Species Richness – the total number of different organisms present. Shannon-Wiener Diversity Index – this measurement takes into account species richness and proportion of each species within the local aquatic community. where pi = the proportion of individuals of species i Maximum diversity possible Evenness Typical values are generally between 1.5 and 3.5 in most ecological studies, and the index is rarely greater than 4. The Shannon index increases as both the rich- ness and the evenness of the community increase. The fact that the index incorpo- rates both components of biodiversity can be seen as both strength and weakness. It is strength because it provides a simple, synthetic summary but it is weakness because it makes it difficult to compare communities that differ greatly in richness. The most common dominance measure is Simpson’s index. Simpson Index – a measurement that accounts for the richness and the per- cent of each species from a biodiversity sample within a local aquatic community. The index assumes that the proportion of individuals in an area indicate their impor- tance to diversity. Simpson’s index is based on the probability of any two individuals drawn at random from an infinitely large community belonging to the same species: 89 where again pi is the proportion of individuals found in species i. For a finite community, this is Interpretation: D is a measure of dominance, so as D increases, diversity (in the sense of evenness) decreases. Thus, Simpson’s index is usually reported as its complement 1-D (or sometimes 1/D or –lnD). Since D takes on values between zero and one and approaches one in the limit of a monoculture, (1-D) provides an intuitive proportional measure of diversity that is much less sensitive to species richness. Simpson’s index: D The probability that two randomly selected individuals in the community be- long to the same category (e.g., species). Simpson’s index of diversity: 1 – D The probability that two randomly selected individuals in a community be- long to different categories (e.g., species). Simpson’s reciprocal index: 1/D The number of equally common categories (e.g. species) that will produce the observed Simpson’s index. D is influenced by two parameters – the equitability of percent of each species present and richness. For a given species richness, D will decrease as the percent of the species becomes more equitable. The indices described above are calculated for two more sites described in previous studies (Kechev, 2012b; Kechev et al., 2014) and Sørensen index, also known as Sørensen similarity coefficient, is calculated: a – common species in region A and B, b – number of species in region A that do not exist in region B, c – number of species in region B that do not exist in region A. Results Faunistic list DIAPHORINAE Schiner, 1864 Argyra argyria (Meigen, 1824) Material examined: 02.V.2013, 3♂♂; 10.V.2013, 1♂; 20.V.2013, 3♂♂; 03.VI.2013, 1♂; 10.VI.2013, 4♂♂; 10.VIII.2013, 1♂; 14.IV.2014, 2♂♂; 21.IV.2014, 1♂, leg. M. Kechev. Distribution: Europe; North Africa: Morocco. 90 Argyra leucocephala (Meigen, 1824) Material examined: 01.VII.2013, 1♂; 10.VII.2013, 2♂♂; 20.VII.2013, 1♂♂; 01.VIII.2013, 1♂; 10.VIII.2013, 1♂; 20.VIII.2013, 6♂♂, 2♀♀; 01.IX.2013, 2♂♂; 10.IX.2013, 2♂♂; 20.IX.2013, 1♀, leg. M. Kechev. Distribution: Europe; North Africa: Algeria, Tunisia. Chrysotus femoratus Zetterstedt, 1843. New to Bulgaria. Material examined: 10.V.2013, 2♂♂; 03.VI.2013, 1♂, 2♀♀; 10.VI.2013, 2♀♀; 20.VI.2013, 1♂, leg. M. Kechev. Distribution: Europa; Transpalaearctic species. DOLICHOPODINAE Latreille, 1809 Dolichopus griseipennis Stannius, 1831 Material examined: 07.X.2013, 1♂, leg. M. Kechev. Distribution: Europe; North Africa: Algeria; Middle Asia. Dolichopus nitidus Fallèn, 1823 Material examined: 20.VIII.2013, 1♀, leg. M. Kechev. Distribution: Europe; Transpalaearctic species; Oriental China. Dolichopus nubilus Meigen, 1824 Material examined: 10.V.2013, 1♂♂; 10.VII.2013, 2♂♂; 20.VII.2013, 1♀; 20.VIII.2013, 1♀, leg. M. Kechev. Distribution: Europe; Asia: China, Kazakhstan, Tajikistan, Uzbekistan. Dolichopus salictorum Loew, 1871 Material examined: 20.V.2013, 3♂♂, 3♀♀; 03.VI.2013, 1♂; 10.VI.2013, 5♂♂, 4♀♀; 20.VI.2013, 1♂, 1♀; 01.VII.2013, 1♂, leg. M. Kechev. Distribution: Bulgaria, Czech Republic, Hungary, Italy, Poland, Slovakia. Gymnopternus metallicus (Stannius, 1831) Material examined: 10.VI.2013, 1♂; 20.VI.2013, 2♂♂, 10.VII.2013, 1♂, 01.VIII.2013, 1♂, 1♀; 10.VIII.2013, 1♂, 1♀, 20.VIII.2013, 2♂♂, leg. M. Kechev. Distribution: Europe; Asia: Iran, Kazakhstan, East Russia: Altai. Hercostomus convergens Loew, 1857 Material examined: 01.VII.2013, 1♂; 20.VII.2013, 1♀, leg. M. Kechev. Distribution: Europe. Hercostomus nanus (Macquart, 1827) Material examined: 02.V.2013, 2♂♂; 10.V.2013, 9♂♂, 5♀♀; 20.V.2013, 2♂♂, 5♀♀, leg. M. Kechev. Distribution: Europe. Hercostomus plagiatus (Loew, 1857). New for Bulgaria. Material examined: 10.V.2013, 1♂; 20.V.2013, 9♂♂, 25♀♀; 03.VI.2013, 7♂♂, 19♀♀; 10.VI.2013, 5♂♂, 2♀♀; 20.VII.2013, 1♂; 01.VIII.2013, 1♂; 10.VIII.2013, 4♂♂; 20.VIII.2013, 8♂♂, 6♀♀; 01.IX.2013, 1♂; 10.IX.2013, 1♂, 1♀; 20.IX.2013, 1♂; 07.X.2013, 1♀, leg.