172 research outputs found

    Aphidius geranii sp. n. (Hymenoptera: Braconidae) from Southeast Europe – a new member of the Aphidius urticae s. str. group

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    Aphidius geranii Tomanovic and Kavallieratos, sp. n., is described as an additional member of the Aphidius urticae s. str. group from high-mountain habitats of Southeast Europe. The new species was reared from Amphorophora sp./Geranium coeruleatum associations. Parasitoid guilds associated with G. coeruleatum are discussed. Key for identification Aphidius spp. on Geranium plants in Europe is given

    Development of a sampling plan for Myzus persicae (Hemiptera : Aphidoidea) and its predator Macrolophus costalis (Hemiptera : Miridae) on tobacco

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    A tobacco field in Greece was sampled during the 2001 and 2002 growing seasons to assess the seasonal trends in densities and spatial distributions of the aphid Myzus persicae (Sulzer) and its predatory mirid Macrolophus costalis (Fieber). On repeated occasions between June Oust after the transplantation) and September Oust before harvest), 20 tobacco leaves (10 from the upper and 10 from the lower plant part) were taken from randomly chosen plants. These leaves were sampled for aphids and mirids. In both years, the highest aphid densities were recorded during July and August, while aphid numbers were low in September. In contrast, the majority of M costalis individuals were found during September when aphid numbers were low. Significantly more M persieae individuals were found in the upper part of the plants, whereas significantly more M costalis individuals were found in the lower part of the plants. As indicated by Taylor's Power Law estimates, both species were aggregated in their spatial distributions among sampling units (leaves). Wilson and Room's model, based on the Taylor's estimates, was used to calculate the mean number of aphids and mirids, from the proportion of sampling units (leaves) that had gt 0 individuals of each species. This model provided a satisfactory fit of the data for both the aphid and the mirid. In addition, Wilson and Room's model was successfully used to predict the mean number of aphids and mirids in a series of samples that were carried out in the same area between June and September 2003 for model validation. Finally, equations are given for the calculation of precision in estimating the mean number of aphids or mirids per sampling unit, and the required sample size for a given level of precision

    Do temperature, relative humidity and interspecific competition alter the population size and the damage potential of stored-product insect pests? A hierarchical multilevel modeling approach

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    The premises of stored agricultural products and food consists of a complex ecosystem in which several pests can seriously affect the quality and quantity of the products. In this study we utilize a 4-level hierarchical linear multilevel model in order to assess the effect of temperature, relative humidity (RH) and interspecific competition on the population size and damage potential of the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae) and the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae). As RH was increased, we observed higher percentage of live insects, while increased levels of temperature significantly decreased the percentage of live insects. The combination of R. dominica and P. truncatus lead to reduction of the percentages of live insects in comparison to single species treatments. However, P. truncatus is more damaging than R. dominica in maize, based on the proportion of damaged kernels which were infested by each insect species. We expect our results to have bearing in the management of these species

    Residual Efficacy of Chlorfenapyr for Control of Stored-Product Psocids (Psocoptera)

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    The residual effect of chlorfenapyr (Phantom) was evaluated for residual control of three stored-product psocid species: Liposcelis bostrychophila Badonnel, Liposcelis entomophila (Enderlein), and Liposcelis paeta Pearman (Psocoptera: Liposcelididae). Chlorfenapyr was applied to individual arenas with a concrete surface at rates of 0, 2.8, 13.8, 20.6, 27.5, 55, and 110 mg active ingredient (AI)/m2. Adults were exposed on the treated arenas and mortality assessed after 1, 2, and 3 d. The procedures were repeated weekly on the same treated arenas for 3 wk to assess residual efficacy. At each week, mortality of all species was low after 1 d of exposure but notably increased after 2 or 3 d. L. entomophila was the most susceptible species, with 99-100% mortality at rates of 13.8 mg/m2 or higher. Similarly, mortality of L. paeta after 3 d of exposure at the same concentration ranged from 92 to 100%. L. bostrychophila was the least susceptible species, with mortality of \u3c60% during the third week after application at rates ≤27.5 mg/m2. However, even for this species, mortality after 3 wk was 90% or higher at rates \u3e27.5 mg/m2. Complete mortality of all species occurred after 3 d exposure at the highest rate tested of 110 mg/m2. Thus, our results show that chlorfenapyr is effective against major psocid species at the application rates evaluated in this study

    Lesser grain borers, \u3ci\u3eRhyzopertha dominica\u3c/i\u3e, select rough rice kernels with cracked hulls for reproduction

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    Tests were conducted to determine whether the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), selects rough rice (Oryza sativa L. (Poales: Poaceae)) kernels with cracked hulls for reproduction when these kernels are mixed with intact kernels. Differing amounts of kernels with cracked hulls (0, 5, 10, and 20%) of the varieties Francis and Wells were mixed with intact kernels, and the number of adult progeny emerging from intact kernels and from kernels with cracked hulls was determined. The Wells variety had been previously classified as tolerant to R. dominica, while the Francis variety was classified as moderately susceptible. Few F1 progeny were produced in Wells regardless of the percentage of kernels with cracked hulls, few of the kernels with cracked hulls had emergence holes, and little frass was produced from feeding damage. At 10 and 20% kernels with cracked hulls, the progeny production, number of emergence holes in kernels with cracked hulls, and the amount of frass was greater in Francis than in Wells. The proportion of progeny emerging from kernels with cracked hulls increased as the proportion of kernels with cracked hulls increased. The results indicate that R. dominica select kernels with cracked hulls for reproduction

    Redescription of two species of Aphidiinae (Hymenoptera: Braconidae) from high mountain areas of south-eastern Europe, with biological and biogeographical notes on co-occurring guild members

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    Praon spinosum Mackauer, 1959 reared from Thrzpsaphis verrucosa Gillette,1917 on Carex nigra and Diaeretellus macrocarpus Mackauer, 1961 reared from the conspecific aphid on Carex rostrata association from Mt. Durmitor Biosphere Reserve in Serbia and Montenegro are redescribed, diagnosed and illustrated with photographs from SEM and line drawings. The taxonomic position of P. spinosum within the genus Praon is discussed. Furthermore, some rare and endemic aphid — aphid-parasitoid associations from high-montane areas of southeastern Europe are reviewed and their distribution and origin is discussed

    First evidence of tick-borne protozoan pathogens, babesia sp. And hepatozoon canis, in red foxes (vulpes vulpes) in Serbia

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    Tick-borne haematozoans cause severe diseases in domestic animals, and some of them have zoonotic potential. The results of previous studies in Europe point to the important role of foxes in natural endemic cycles of several tick-borne pathogens, including protozoa. The aim of the present research was to acquire information on the prevalence and distribution of tick-borne protozoan parasites among foxes in Serbia. Legally hunted foxes from 14 localities throughout Serbia were analysed. Spleen samples were collected from 129 animals and tested for the presence of Babesia spp. and Hepatozoon spp. by PCR. In total, 79/129 (61.2%) of the tested foxes were positive for H. canis, while the presence of two Babesia species was confirmed: B. vulpes (37/129, 28.7%) and B. canis (1/129, 0.8%). Co-infection with B. vulpes and H. canis was present in 26/129 (20.2%) foxes and one animal (1/129, 0.8%) was co-infected by B. canis and H. canis. The results of this study indicate the important role of foxes in the epizootiology of B. vulpes and H. canis in the Republic of Serbia and stress the need for further research to clarify all elements of the enzootic cycle of the detected pathogens, including other reservoirs, vectors, and transmission routes

    Phylogeny of the Subtribe Monoctonina (Hymenoptera, Braconidae, Aphidiinae)

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    Abstract: Members of the Monoctonina subtribe have long been neglected in applied studies of the subfamily Aphidiinae, due to their low economic importance, as they do not parasitize pests of cultivated plants. Consequently, data about this group are scarce, including its taxonomy and phylogeny. In the present study, we explore inter- and intraspecific genetic variation of Monoctonina species, including genera Monoctonus Haliday 1833, Monoctonia Starý 1962, Falciconus Mackauer 1959 and Harkeria Cameron 1900. We employ two molecular markers, the barcode region of the mitochondrial cytochrome c oxidase subunit I (COI) and the D2 region of the 28S nuclear gene (28S rDNA), to analyze genetic structuring and phylogeny of all available Monoctonina species, and combine them with morphological data for an integrative approach. We report one new species, and three potentially new species which can be formally described when further specimens are available. Analysis of phylogenetic relationships within the subtribe shows a basal position for the genera Falciconus and Monoctonia, and the close relatedness of Harkeria and Monoctonus

    Vrste roda Aphidius nees (hymenoptera, braconidae, aphidiinae) u Srbiji i Crnoj Gori - tritrofičke zajednice i ključ

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    In the present paper we review 26 Aphidius species from 162 tritrophic associations in Serbia and Montenegro. Aphidius species were reared from over 64 aphid hosts. A key for the identification of species is provided.U radu je dat pregled 26 vrsta roda Aphidius sa 162 različite trofičke zajednice u Srbiji i Crnoj Gori dobijene gajenjem preko 64 afidna domaćina. Dat je i originalni ključ za identifikaciju vrsta roda Aphidius

    (Quasi)-binomial vs. Gaussian models to evaluate thiamethoxam, pirimiphos-methyl, alpha-cypermethrin and deltamethrin on different types of storage bag materials against Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae)

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    The Mediterranean flour moth, Ephestia kuehniella Zeller (Lepidoptera: Pyralidae) and the confused flour beetle, Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) are worldwide spread and notorious organisms of numerous stored-products. Both species are dangerous for bagged commodities as penetrators and invaders. The aim of the current study was to examine the efficacy of thiamethoxam, pirimiphos-methyl, alpha-cypermethrin, and deltamethrin, against E. kuehniella and T. confusum larvae, on different types of storage bag materials, i.e., woven propylene, biaxially oriented polypropylene and kraft paper through a (quasi)-binomial modeling approach. The type of the tested storage bag material did not affect the mortality rates of both species when treated with the tested insecticides. Thiamethoxam and pirimiphos-methyl showed statistically significant higher mortality rates on E. kuehniella and T. confusum (beta coefficient = 0.141; p-value < 0.05) compared to alpha-cypermethrin and deltamethrin. In addition, T. confusum exhibited significantly higher mortality rate in comparison to E. kuehniella. Our results also showed that the tested doses and surface treatments had a significant effect on the mortality E. kuehniella and T. confusum larvae. Significantly higher mortality rates were recorded when larvae were exposed on bag materials having both surfaces treated or on the single treated surface than when they were exposed on the untreated surface. Our findings can be useful towards an effective management strategy against stored-product insect pests
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