726 research outputs found

    Use of Ethanol-and-Turpentine-Baited Flight Traps to Monitor \u3ci\u3ePissodes\u3c/i\u3e Weevils (Coleoptera: Curculionidae) in Christmas Tree Plantations

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    Pissodes nemorensis and Pissodes strobi are major pests of pine production in eastern North America. Ethanol-and-turpentine baited traps were used here to monitor weevil populations in a Scotch pine Christmas tree plantation in Wisconsin. Baited pitfall traps were ineffective in trapping either weevil species. However, baited flight traps at 0.8 and 1.6 m above ground effectively captured flying weevils of both species, 70% of which were P. nemoren­sis. Females of both species were more attracted than males to the ethanoll turpentine baits. Significantly more female P. nemorensis and total P. nemorensis were trapped at a height of 0.8 m than 1.6 m. There was no significant difference in male P. nemorensis response to the different heights, nor was there a significant difference in response to trap height by P. strobi

    Use of a Monitoring System to Evaluate Pesticide Efficacy and Residual Activity Against Two Pine Root Weevils, \u3ci\u3eHylobius Pales\u3c/i\u3e and \u3ci\u3ePachylobius Picivorus\u3c/i\u3e (Coleoptera: Curculionidae), in Christmas Tree Farms

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    Hylobius pales, the pales weevil, and Pachylobius picivorus, the pitch-eating weevil, comprise part of a weevil complex which affects plantation pine production in the Lake States. Common control practices on Christmas tree farms include calendar applications of persistent insecticides. The resulting environmental risks could be minimized by repeating applications only when needed. A sampling method using ethanol-and turpentine-baited pitfall traps was used here to assess the efficacy and monitor persistence of chemical sprays. Trap catch in lindane-treated field plots and untreated controls were compared over two years. Unsprayed controls had significantly higher weevil populations than treated plots. Spray efficacy continued for three years following tion. Weevil population growth in relation to insecticide efficacy and degradation is discussed

    Orientation of \u3ci\u3eHylobius Pales\u3c/i\u3e and \u3ci\u3ePachylobius Picivorus\u3c/i\u3e (Coleoptera: Curculionidae) to Visual Cues

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    Pitfall traps with above-ground silhouettes of various colors and diameters were used in field tests to evaluate the role of vision in host orientation by adult pales weevils, Hylobius pales, and pitch-eating weevils, Pachylobius picivorus. White traps (11 em outer diameter) baited with ethanol and turpentine caught significantly more weevils than similarly baited black or green traps (11 cm outer diameter). Trap diameter (range of 6-22 cm outer diameter) did not affect trap catch. Pitfall traps can be used to monitor root weevil populations in young pine plantations and Christmas tree farms, where they are major pests. These results demonstrate that visual and chemical cues can be integrated to improve trap efficiency

    Assemblage of Hymenoptera Arriving at Logs Colonized by \u3cem\u3eIps pini\u3c/em\u3e (Coleoptera: Curculionidae: Scolytinae) and its Microbial Symbionts in Western Montana

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    Colonization of a tree by bark beetles and their symbionts creates a new habitat for a diverse assemblage of arthropods, including competing herbivores, xylophages, fungivores, saprophages, predators, and parasitoids. Understanding these assemblages is important for evaluating nontarget effects of various management tactics and for subsequently evaluating how changes in climate, the presence of invasive species, and altered forestry practices and land-use tenure may affect biodiversity. We characterized the assemblage of hymenopterans attracted to logs of ponderosa pine (Pinus ponderosa C. Lawson (Pinaceae)) colonized by the bark beetle Ips pini (Say) and its microbial symbionts. In one experiment, the composition and relative abundances of species arriving at hosts colonized by I. pini, and possible sources of attraction, were determined. Treatments consisted of a log containing I. pini with its natural complement of microorganisms, a log alone, and a blank control. A second experiment was carried out to determine whether or not Hymenoptera were attracted to microbial symbionts of I. pini. Treatments consisted of a blank control, a log alone, a log containing I. pini with its natural complement of microorganisms, either Ophiostoma ips, Burkholderia sp., or Pichia scolyti, and a log inoculated with a combination of these three microorganisms. Over 2 years, 5163 Hymenoptera were captured, of which over 98% were parasitoids. Braconidae, Platygastridae, Encyrtidae, Pteromalidae, and Ichneumonidae were the most abundant. Seven known species of bark beetle parasitoids (all Pteromalidae) were captured. However, parasitoids of Diptera, Lepidoptera, Hymenoptera, and non-wood-boring Coleoptera were also common. Nineteen species showed preferential attraction to host plants infested with I. pini and its complement of microorganisms, host plants inoculated with I. pini microbial symbionts, or host plants alone. Interestingly, many of these species were parasitoids of phytophagous, fungivorous, and saprophytic insects rather than of bark beetles themselves. These results suggest that a diverse assemblage of natural enemies that attack various feeding guilds within a common habitat exploit common olfactory cues

    Synthesis of zwitterionic copolymers via copper-mediated aqueous living radical grafting polymerization on starch

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    [2-(Methacryloyloxy)ethyl]dimethyl-(3-sulfopropyl)ammonium hydroxide (SBMA) is a well-studied sulfobetaine-methacrylate as its zwitterionic structure allows the synthesis of polymers with attractive properties like antifouling and anti-polyelectrolyte behavior. In the present work, we report the Cu0-mediated living radical polymerization (Cu0-mediated LRP) of SBMA in sodium nitrate aqueous solution instead of previously reported solvents like trifluoroethanol and sodium chloride aqueous/alcoholic solution. Based on this, starch-g-polySBMA (St-g-PSBMA) was also synthesized homogeneously by using a water-soluble waxy potato starch-based macroinitiator and CuBr/hexamethylated tris(2-aminoethyl)amine (Me6TREN) as the catalyst. The structure of the macroinitiator was characterized by 1H-NMR, 13C-NMR, gHSQC, and FT-IR, while samples of PSBMA and St-g-PSBMA were characterized by 1H-NMR and FT-IR. Monomer conversion was monitored by 1H-NMR, on the basis of which the reaction kinetics were determined. Both kinetic study and GPC results indicate reasonable controlled polymerization. Furthermore, a preliminary study of the thermal response behavior was also carried through rheological tests performed on aqueous solutions of the prepared materials. Results show that branched zwitterionic polymers are more thermal-sensitive than linear ones.</p

    BNNT- Mediated Irreversible Electroporation: It\u27s Potential on Cancer Cells

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    Irreversible lethal electroporation (IRE) is a new non-thermal ablation modality that uses short pulses of high amplitude static electric fields (up 1000V/cm) to create irreversible pores in the cell membrane, thus, causing cell death. Recently, IRE has emerged as a promising clinical modality for cancer disease treatment. Here, we investigated the responses of tumour human He La cells when subjected to IRE in the presence of BNNTs. These consist of tiny tubes of B and N atoms (arranged in hexagons) with diameters ranging from a 1 to 3 nanometres and lengths \u3c2 μm. BNNTs have attracted wide attention because of their unique electrical properties. We speculate that BNNTs, when interacting with cells exposed to static electrical fields, amplify locally the electric field, leading to cell death. In this work, electroporation assays were performed with a commercial electroporator using the cell-specific protocol suggested by the supplier (exponential decay wave, time constant 20ms) with the specific aim to compare IRE in absence and in presence of BNNTs. We observed that BNNTs have the capacity to decrease substantially the voltage required for IRE. When cells were pulsed at 800V/cm, we observed a 2,2-fold reduction in cell survival in the presence of BNNTs compared to controls. We conclude that the death of the tumour cells exposed to IRE is strongly enhanced in the presence of BNNTs, indicating their potential therapeutic application

    Polaron Effects on Superexchange Interaction: Isotope Shifts of TNT_N, TCT_C, and T∗T^* in Layered Copper Oxides

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    A compact expression has been obtained for the superexchange coupling of magnetic ions via intermediate anions with regard to polaron effects at both magnetic ions and intermediate anions. This expression is used to analyze the main features of the behavior of isotope shifts for temperatures of three types in layered cuprates: the Neel temperatures (TNT_N), critical temperatures of transitions to a superconducting state (TCT_C), and characteristic temperatures of the pseudogap in the normal state (T∗T^*).Comment: 4 pages, 1 figur
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