Sixth International Scientific Agricultural Symposium „Agrosym 2015“ Original scientific paper 10.7251/AGSY15051106T DIVERSITY OF LEAFMINERS OF PEAR IN THE REGION OF EAST SARAJEVO Dejana TEŠANOVIĆ1, Radoslava SPASIĆ2 1Faculty of Agriculture,University of East Sarajevo, Bosnia and Herzegovina 2Faculty of Agriculture, University of Belgrade, Serbia *Corresponding author: [email protected] Abstract Diversity of leafminers in region of East Sarajevo, was examined in 2011. and 2012. in intensive plantations (locations Vojkovici and Kula), in semi-intensive plantations (locations Tilava and Petrovici) and in extensive plantation (location Kasindo). In Kula, examination was done on the following cultivars: „Viljamovka“ (Bartlett/Wiliams), General Le Clerc, „Passa Crasana“, Abe Fetel and Poire de Curé. Six species of leafminers from four families was determined. Family Lithocolletidae is presented with three species: spotted tentiform leafminer miner (Lithocoletis blancardella Fabricius), hawthorn red midget moth (Lithocoletis corylifoliella Haworth) and garden apple slender (Calisto denticulella Thunberg), family Nepticulidae with one: apple pigmy (Stigmella malella Stainton) and from the family Lyonetiidae, two species was found: pear leaf blister moth (Leucoptera malifoliella (Costa (1836)) and Coleophora hemerobiella Scopoli from family Coleophoridae. The highest number of damaged leaves was found in the semi-intensive plantations, in localities Tilava and Petrovici, where S. malella and C. denticulella were dominated species. In intensive plantations, in the locality Vojkovici, only S. malella was found. In the locality Kula, except S. malela which was the most numerous on pear cv. the Williams, L. blancardella was also determined. In extensive orchards, in the locality Kasindo, the most common species was C. denticulella. Keywords: leafminers, pear, East Sarajevo. Introduction Leafminers from order Lepidoptera are economically important pests in areas where pears are grown. The damage are caused by larvae that are feed on the leaf parenchyma below the epidermis, leaving empty couloir, or "mine" of different shapes and sizes. The presence of mines on leaves reduces assimilation and transpiration surface, which adversely affects the yield, fruit quality and, in general, physiological condition of plants. Importance of these pests and their negative impact on fruit production, started increasing during end of the 60´s in the XX century. Leafminers became a serious problem, particulary in plantations in most European countries (Dimic, 1964, 1968). The presence and importance of different species of isn't the same in all areas of their distribution. In Europe, more than 20 species of leafminers from genera: Coleophora, Leucoptera, Stigmella, Lyonetia, Lithocolletis, Incurvaria, Recurvaria and Calisto were detected on the pear (Hering, 1957). The most important species on the pear are: Lyonetia clerkella, Leucoptera malifoliella, Lithocolletis blancardella, Lithocolletis corylifoliella and Callisto denticulella (Almasi et al., 2004). In Turkey, for example, three species was identified on pear: Lyonetia prunifoliella (Hubner, 1796), Lyonetia clerkella and Leucoptera malifoliella (Seven, 2006). After Lithocolletis blancardella was introduce in North America from Europe, it became an important pest (Corrigan and Bennett, 1987), and a increasing problem in plant production, because of its resistance to organophosphorus insecticides, especially azinphos- methyl (Hogmire and Beavers, 1998). 1106 Sixth International Scientific Agricultural Symposium „Agrosym 2015“ In Romania, in pear orchards, the most important species are L. blancardella and Lithocolletis corylifoliella (Frasin et al., 2008; Vasian et al., 2013). In the former Yugoslavia, a mass phenomenon leafminers occurred in the late 70´s in XX century, when they became a serious problem. For example, eight leafminer species were detected on the pear in Slovenia: Lyonetia clerkella, Lithocolletis corylifoliella, Lithocolletis cerasicolella, Calisto denticulella, Stigmella pomella, Stigmella piri, Stigmella plagicollella, Stigmella prunetorum. In Serbia and Croatia were registered five leafminer species: Leucoptera malifoliella, Lyonetia clerkella, Lithocolletis corylifoliella, L. blancardella and Stigmela malella (Krnjaić and Grujic, 1982). Distribution and harmfulness caused by leafminers were studied in Bosnia and Herzegovina during the 60´s, when a rapid increase in population density and damages were registered. In that period, a total of 45 species of leafminers were found, out of which in Sarajevo and its wider area 5 species was recorded on the pear: L. corylifoliella, L. mespiliella Frey, Lyonetia clerkella, Cemiostoma scitella and Coleophora hemerobiella. In that period, according to the intensity of the attack, the most harmful was L. corylifoliella, especially on young trees (Dimic, 1964, 1968). The area which now includes the East Sarajevo presents a part of the Sarajevo region and there are not enough data regarding harmful leafminers on pears. The tendency of increasing the production of pears in this area in the last 10 years, resulted in establishment the new, intensive plantations. Having in mind that leafminers are economically important pests of pear, the aim of this study was to register their diversity, to detect the most numerous species, as well differences in their number, both in plantations where different growing tehniques are aplied, as well between the cultivars. Materials and methods The examination was realized in 2011. and 2012. in the field (locations Vojkovici, Kula, Tilava, Petrovici, Kasindo) and in the laboratory of the Agricultural faculty in East Sarajevo. Samples of pear leaves were taken four times from June to the end of October for leafimers presence in all inspected locations. Every time 100 randomly sampled leaves were taken from pear trees (total of 400 leaves per each locality), except in the locality Kula, where 400 leaves of each variety was sampled. All sampled leaves were observed in laboratory for presence of mines as well the type of mines. Number of damaged leaves was calculated. The before adult stadium of insects who located in the mines, were reared to adult stadium. The rearing was in plastic containers and Petri dishes with a layer of cellulose wadding on the bottom of which is occasionally yeast in order to maintain the freshness of the list. Determination of species was based on morphological characteristics of the adults and shapes of mines, folloowed by keys and appropriate entomological literature (Balachowsky 1966, Hering, 1957). Results and discussions Two-year research of diversity of leafminers on pears in the area of East Sarajevo, resulted in six detected species from four families. From family Lithocolletidae, three species were found: Lithocoletis blancardella Fabricius, Lithocoletis corylifoliella Haworth and Calisto denticulella Thunberg. From family Nepticulidae results of our examination showed presence of Stigmela malella Stainton, from family Lyonetiidae it was Leucoptera malifoliella (Costa (1836)), while Coleophora hemerobiella Scopoli which belongs to family Coleophoridae, was found only in certain leaves. The number of damaged leaves, varied by the species of leafminers and inspected cultivars (Table 1). Regarding the total number of 323 damage leaves, found in all inspected localities, the most numerous species was S. malella, whose mines were registered in 125 leaves or 38,69%, followed by C. denticulella (97 leaves or 30,03%) and L. blancardella with 74 damaged leaf 1107 Sixth International Scientific Agricultural Symposium „Agrosym 2015“ or 22,91%. The lowest number of damaged leaves was caused by L. corylifoliella (20 leaves or 6,19% ) and L. malifioliella (7 mined leaves or 2,16%). Table. 1. The number of mined leaves on pear by species of leafminers and localities Species of leaf miners Leucoptera Lithocoletis Lithocoletis Stigmela Calisto malifoliella blancardella corylifoliella malella denticulella Total number Locality of mined leaves in of of of of of localities % % % % % Number mined leaves Number mined leaves Number mined leaves Number mined leaves Number mined leaves Vojkovici - - - - - - 13 3,25 - - 13 Кula - - 11 37,93 - - 18 62,06 - - 29 Tilavа 7 5,69 26 21,13 9 7,32 45 36,59 36 29,26 123 Petrovici - - 18 23,68 11 14,47 21 27,63 26 34,21 76 Kasindo - - 19 23,17 - - 28 34,15 35 42,68 82 Total number of leaves 7 (2,16%) 74 (22,91%) 20 (6,19%) 125 (38,69%) 97 (30,03%) 323 mined by species The highest number of mined leaves was found in the locality Tilava were 123 leaves in total were damaged or 30,75%. Out of total number of leaves with „mines“ from this locality, it was found that the most abundant was S. malella which damaged 45 or 36,59% leaves, C. denticulella with 36, or 29,26%, and L. blancardella with 26, or 21,13% of damaged leaves. Leaves were damaged the least by L. malifioliella, 7 or 5,69%, while L. corylifoliella damaged 9 or 7,32% leaves. In the locality Petrovici, out of the total number of examined leaves, 76 leaves or 19% were damaged. The most abundant species was C. denticulella which damaged 26, or 34,21%, and is followed by S. malella with 21 or 27,63%, L. blancardella with 18, or 23.68%, while the L. corylifoliella was of lower presence with 11, or 14,47% damaged leaves. In locality Kasindo, the most abundant species was C. denticulella with 35 or 42,68% damaged leaves, and S. malella with 28, or 34,15%, while the lowest number of damaged leaves was