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Featured researches published by Vladimir Žikić.


Annals of The Entomological Society of America | 2009

Morphological Characterization of Ephedrus persicae Biotypes (Hymenoptera: Braconidae: Aphidiinae) in the Palaearctic

Vladimir Žikić; Željko Tomanović; Ana Ivanović; Nickolas G. Kavallieratos; Petr Starý; Ljubiša Ž. Stanisavljević; Ehsan Rakhshani

ABSTRACT Ephedrus persicae Froggatt (Hymenoptera: Braconidae: Aphidiinae) represents a biologically complex parasitoid species group that parasitizes >150 aphid species worldwide, including many pests in different agroecosystems. Evidence from the host range indicated some taxonomic problems within this species-complex. Using classical and geometric morphometric approaches, we assessed the morphological differences among various E. persicae biotypes in the Palaearctic reared from 20 aphid hosts. We found that morphological variability of E. persicae biotypes was influenced by the host. Classical morphometric analysis indicated a conservative position of E. persicae biotypes in the Palaearctic. Our analysis showed that E. persicae biotypes reared from nonleaf-curling Aphis and leaf-curling Dysaphis aphid hosts have significant differences, but all other analyzed E. persicae biotypes have an intermediate position, making it impracticable to split the E. persicae group this way. However, geometric morphometrics used to analyze variation of wing shape showed better predictive ability. The high ratio of correctly assigned individuals based on the wing shape of E. persicae/Aphis viticis Ferrari, E. persicae/Brachycaudus klugkisti (Börner), and E. persicae/Tuberocephalus momonis (Matsumura) biotypes indicates that some host-specific adaptations occurred. The E. persicae/ Hyadaphis foeniculi (Passerini) biotype is clearly separated along the CV2 canonical axis, exhibiting shorter and wider wings. On the basis of this result, we describe a new taxon—Ephedrus lonicerae n. sp.


Annals of The Entomological Society of America | 2010

Parasitoids (Hymenoptera: Braconidae: Aphidiinae) attacking aphids feeding on Solanaceae and Cucurbitaceae crops in southeastern Europe: aphidiine-aphid-plant associations and key.

Nickolas G. Kavallieratos; Željko Tomanović; Petr Starý; Vladimir Žikić; Olivera Petrović-Obradović

ABSTRACT Original information on aphidiine braconids attacking aphids feeding on Solanaceae (i.e., Capsicum annuum L., Lycium europaeum L., Lycopersicon esculentum Miller, Solanum spp.) and Cucurbitaceae (i.e., Citrullus vulgaris Schrad., Cucumis spp., Cucurbita pepo L.) plants in southeastern Europe is presented. A total of 13 species are keyed and illustrated with scanning electron micrographs, microscope micrographs and line drawings. The aphidiines presented in this work have been identified from nine aphid taxa. Two hundred four aphidiine-aphid-plant associations are presented, 176 of which are new. The results are discussed in relation to over-all parasitoid-aphid-plant associations in the area.


Bulletin of Entomological Research | 2013

Lysiphlebus orientalis (Hymenoptera, Braconidae), a new invasive aphid parasitoid in Europe - evidence from molecular markers

Andjeljko Petrović; Milana Mitrović; Petr Starý; Olivera Petrović-Obradović; Vladimir Žikić; Željko Tomanović; Christoph Vorburger

We report the occurrence of Lysiphlebus orientalis in Serbia, an aphid parasitoid from the Far East that is new to Europe and has the potential to become invasive. Our finding based on morphological characters is confirmed by analyses of mitochondrial cytochrome oxidase subunit I sequences. An increase in number and an expansion of the host range were observed during field studies over the past two years, and it is determined that the current host range encompasses nine aphid hosts on 12 different host plants, forming 13 tri-trophic associations. A host range determined for European populations of L. orientalis appears wider compared with that in its Far Eastern native habitats where Aphis glycines Mats. is the sole known host. Moreover, it overlaps considerably with the host ranges of European parasitoids that play an important role in the natural control of pest aphids.


Canadian Entomologist | 2007

Phylogenetic relationships between the genera Aphidius and Lysaphidus (Hymenoptera: Braconidae: Aphidiinae) with description of Aphidius iranicus sp. nov

Željko Tomanović; Ehsan Rakhshani; Petr Starý; Nickolas G. Kavallieratos; Ljubiša Ž. Stanisavljević; Vladimir Žikić; Christos G. Athanassiou

We analyzed the phylogenetic relationships between eight Aphidius Nees and six Lysaphidus Smith species on the basis of 12 morphological characters by parsimony analysis. The consensus tree does not support the generic status of Lysaphidus. Aphidius iranicus, sp. nov., associated with Titanosiphon bellicosum Nevsky on Artemisia absinthium L. from Iran, is described. The new parasitoid species is described and illustrated by line drawings, and its diagnostic characters are discussed. The taxonomic position of the subgenus Tremblayia Tizado and Núñez-Pérez is also considered. Tremblayia and Lysaphidus are newly classified as synonyms of Aphidius. The following new or revised combinations are proposed: Aphidius adelocarinus Smith, comb. rev., A. ramythirus Smith, comb. rev., A. rosaphidis Smith, comb. rev., A. viaticus (Sedlag), comb. nov., A. arvensis (Starý), comb. nov., and A. erysimi (Starý), comb. nov.


Annals of The Entomological Society of America | 2013

Identification of Two Cryptic Species within the Praon abjectum Group (Hymenoptera: Braconidae: Aphidiinae) using Molecular Markers and Geometric Morphometrics

Ana Mitrovski-Bogdanović; Andjeljko Petrović; Milana Mitrović; Ana Ivanović; Vladimir Žikić; Petr Starý; Christoph Vorburger; Željko Tomanović

ABSTRACT The genus Praon represents a large group of aphid endoparasitoids and is exemplary for the problems encountered in their taxonomy because of a great variability of morphological characters. To investigate the intraspecific variability and to ascertain cryptic speciation within the Praon abjectum Haliday group, biotypes in association with the aphid hosts Aphis sambuci L., Longicaudus trirhodus Walker, and Rhopabsiphum spp. were examined. We combined molecular and geometric morphometric analyses, that is, partial sequences of the mitochondrial cytochrome oxidase subunit I and nuclear 28SD2 genes and the shape of the forewing. Low variation of 28SD2 sequences confirmed the close relatedness of species from the genus Praon. Analysis of the cytochrome oxidase subunit I sequences however identified three separate taxa within the P. abjectum group with substantial genetic divergence. The biotype of P. abjectum associated with L. trirhodus differed from those associated with Rhopabsiphum sp. and A. sambuci by 5.4–6.5% and 7.7% sequence divergence, respectively, while the genetic distance between the latter two biotypes ranged from 9.5 to 10%. The main changes in the forewing shape that discriminate these three biotypes as revealed by geometric morphometrics are related to the stigma shape and the position of the radial nerve. Based on the differences determined in mitochondrial sequences and in the shape of the wing, we describe two new cryptic species within the P. abjectum group as follows: P. sambuci sp. n. in association with A. sambuci/S. nigra and P. longicaudus sp. n. in association with L. trirhodus/T. aquilegifolium.


Biologia | 2007

Aphids (Hemiptera: Aphidoidea) on cultivated and self-sown plants in Greece

Nickolas G. Kavallieratos; Željko Tomanović; George P. Sarlis; Basileios J. Vayias; Vladimir Žikić; Nickolas E. Emmanouel

The present work covers original information on aphids (Hemiptera: Aphidoidea) from Greece during 1995–2005. The individual aphid taxa were collected from their host plants and identified. The plant taxa were classified in two major categories: cultivated and self-sown. The cultivated ones were classified as: herbaceous, climbing and trees. The selfsown ones were classified as: annual herbaceous, annual or biennial herbaceous, biennial or perennial herbaceous, perennial herbaceous, shrubby and trees Two hundred twelve plant taxa were identified on which 105 aphid taxa were recorded. We report 391 plant taxa-aphid taxa associations from which, 190 are referred to cultivated and 201 to self-shown plant taxa. Aphis gossypii was found to infest the widest spectrum of cultivated plant taxa whereas Brachycaudus helichrysi was found to infest the widest spectrum of self-sown plant taxa. Myzus persicae was found to infest the widest spectrum of the total number of plant taxa. Information for several economically unimportant aphid taxa in the area are also presented.


BMC Evolutionary Biology | 2015

Genetic and morphological variation in sexual and asexual parasitoids of the genus Lysiphlebus - an apparent link between wing shape and reproductive mode.

Andjeljko Petrović; Milana Mitrović; Ana Ivanović; Vladimir Žikić; Nickolas G. Kavallieratos; Petr Starý; Ana Mitrovski Bogdanović; Željko Tomanović; Christoph Vorburger

BackgroundMorphological divergence often increases with phylogenetic distance, thus making morphology taxonomically informative. However, transitions to asexual reproduction may complicate this relationship because asexual lineages capture and freeze parts of the phenotypic variation of the sexual populations from which they derive. Parasitoid wasps belonging to the genus Lysiphlebus Foerster (Hymenoptera: Braconidae: Aphidiinae) are composed of over 20 species that exploit over a hundred species of aphid hosts, including many important agricultural pests. Within Lysiphlebus, two genetically and morphologically well-defined species groups are recognised: the “fabarum” and the “testaceipes” groups. Yet within each group, sexual as well as asexual lineages occur, and in L. fabarum different morphs of unknown origin and status have been recognised. In this study, we selected a broad sample of specimens from the genus Lysiphlebus to explore the relationship between genetic divergence, reproductive mode and morphological variation in wing size and shape (quantified by geometric morphometrics).ResultsThe analyses of mitochondrial and nuclear gene sequences revealed a clear separation between the “testaceipes” and “fabarum” groups of Lysiphlebus, as well as three well-defined phylogenetic lineages within the “fabarum” species group and two lineages within the “testaceipes” group. Divergence in wing shape was concordant with the deep split between the “testaceipes” and “fabarum” species groups, but within groups no clear association between genetic divergence and wing shape variation was observed. On the other hand, we found significant and consistent differences in the shape of the wing between sexual and asexual lineages, even when they were closely related.ConclusionsMapping wing shape data onto an independently derived molecular phylogeny of Lysiphlebus revealed an association between genetic and morphological divergence only for the deepest phylogenetic split. In more recently diverged taxa, much of the variation in wing shape was explained by differences between sexual and asexual lineages, suggesting a mechanistic link between wing shape and reproductive mode in these parasitoid wasps.


Canadian Entomologist | 2009

Sexual Dimorphism in Ephedrus persicae (Hymenoptera: Braconidae: Aphidiinae): Intraspecific Variation in Size and Shape

Ana Mitrovski Bogdanović; Ana Ivanović; Željko Tomanović; Vladimir Žikić; Petr Starý; Nickolas G. Kavallieratos

Abstract Sexual dimorphism in size and shape has been studied in a wide range of organisms, but intraspecific variation in sexual dimorphism remains largely unexplored. In many parasitoid species the diversity of morphological-variation patterns within species is complicated by host effects. It is not known whether the magnitude and direction of sexual size dimorphism can be affected by the developmental environment (i.e., different host species). In this study we explored patterns of sexual dimorphism in size and shape in the aphid parasitoid Ephedrus persicae Froggatt. The analyzed sample consisted of 83 females and 54 males reared from five species of host aphids (Hemiptera: Aphididae) from various areas of the Palaearctic region. The most notable result of the study is that E. persicae displays divergent patterns of sexual dimorphism in body size and wing size: females have larger bodies than males, but males have larger wings. Our analysis of wing size and wing shape also showed significant within-species variation in the degree and pattern of sexual dimorphism. Variation in wing shape between the sexes seems to be more conserved than variation in wing size. Variation in wing shape is influenced predominantly by host (biotype) and to a lesser extent by sexual dimorphism within a biotype.


Zootaxa | 2014

Contributions to the Opiinae (Hymenoptera: Braconidae) of Eastern Iran with updated checklist of Iranian species

Nahid Khajeh; E. Rakhshani; Francisco Javier Peris-Felipo; Vladimir Žikić

The present work collects the checklist of species of Opiinae (Hymenoptera: Braconidae) from Iran and presents new information about the specimens captured in the Sistan and Baluchestan province during 2009-2011. A total of 68 species belonging to eight genera have been listed, of which nine species including Opius (Hypocynodus) arundinis Fischer, 1964a; Opius (Hypocynodus) bouceki (Fischer, 1958b); Opius (Opius) caricivorae Fischer, 1964b; Opius (Opius) exilis Haliday, 1837; Opius (Opiothorax) opacus Fischer, 1968; Opius (Allophlebus) tabificus Papp, 1979; Phaedrotoma biroica (Fischer et Beyarslan 2005a); Phaedrotoma mirabunda (Papp, 1982) and Xynobius rudis (Wesmaelm, 1835) are new records from Iran.


Entomological News | 2014

Altitudinal Zonation of Aphid Parasitoids (Hymenoptera: Braconidae: Aphidiinae) in the Neotropical Region

Petr Starý; Ehsan Rakhshani; Vladimir Žikić; Nickolas G. Kavallieratos; Blas Lavandero; Željko Tomanović

ABSTRACT: The paper presents 19 identified species of aphid parasitoids belonging to eight genera in the high altitudes of Central and South America, along with seven unidentified species. Faunal analysis indicates that most of the lowland areas are inhabited by a set of pan-tropical, cosmopolitan, and Nearctic parasitoid aphid associations, whereas the higher altitudes of Central and northern South America are characterized by a mix of trans-zonal species and a rather specific fauna. The Nothofagus — aphid — parasitoid associations are endemic and distributed from the high Andes down to western Patagonia.

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Petr Starý

Academy of Sciences of the Czech Republic

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Christoph Vorburger

Swiss Federal Institute of Aquatic Science and Technology

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