3,581 research outputs found

    A survey of natural parasitism of mirid bugs by parasitoids on apples and pears in Norway

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    Mirid bugs are important pests in both integrated and organic fruit production. In a survey in 2006 the proportion of mirids parasitized by parasitoids was investigated in 18 Norwegian orchards. More than 50 beating samples were collected from apple and pear orchards under integrated and organic management in different areas of Norway. About 30% of nymphs of the most abundant mirid bug species, Lygocoris pabulinus, Ortholylus marginalis and Psallus ambiguus, were parasitized. Important factors for enhancing biological control in organic fruit production are discussed

    Pilot field studies on insect pathogenic fungi to control mirid pests of apples in Norway

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    In a pilot field study conducted in an apple orchard in Hardanger (Western Norway) in two succesive years both Beauveria bassiana and Metarhizium anisopliae were applied to apple trees just after hatching of mirid nymphs in spring. Both predatory, omnivorous and principally plant-pathogenic species of mirids were collected, and all groups of species were infected by B. bassiana or M. ansiopliae in treated plots. B. bassiana and M. anisopliae were also found on some individuals in non treated control plots the second year. M. anisopliae was more predominant in 2006, B. bassiana in 2007. Mirids were also observed for natural occurrence of parasitoids, and parasitoids were found both years

    Screen Barriers for Reducing Interplot Movement of Three Adult Plant Bug (Hemiptera: Miridae) Species in Small Plot Experiments

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    Fiberglass screen barriers 1.2 m high were erected around small (7.3 x 3.7 m) plots of birdsfoot trefoil, Lotus corniculatus, to study the effectiveness of screen barriers in reducing adult plant bug migration into small field plots. Screened and unscreened (control) plots were sprayed with an insecticide at the onset of the experiment, and subsequent adult mirid migration into these trefoil plots was measured by sweep net samples during the following 24 day period. Combined adult Adelphocoris lineolatus, Lygus lineolaris, and Plagiognathus chrysanthemi densities were significantly lower in screened versus unscreened plots with 37070, 28010, and 23070 fewer adults at 7, 17, and 24 days, respectively, following insecticide application. Although these barriers were inexpensive and simple to construct, we conclude that they were not practical and effective enough for reducing adult mirid migration in small plot experiments of this type

    Cocoa Yield Development of Different Sites, Varieties, Production Systems and Years, in Alto Beni, Bolivia

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    One of the most essential limiting factors of cocoa (Theobroma cacao L.) productivity worldwide is pests and diseases. Each of the major production regions has its specific pests and diseases. Reported yield losses range from minor to almost 100 per cent. In Alto Beni, located in the Amazonian watershed of the department La Paz, Bolivia, the Research Institute of Organic Agriculture (FiBL) and its local partners are addressing several problems of cocoa producers using a participatory technology development approach. Problems were identified in a participatory way and are, in order of priority, i) to reduce the incidence of pests and diseases, mainly the cocoa mirid (Monalonion dissimulatum) and Frosty Pod Rot (Moniliophthora roreri); ii) to evaluate the productivity of different cocoa varieties (local selections, introduced clones), and iii) to document the management practices and plantation layouts of high yielding cocoa farmers. In order to develop novel biological pest control measures, both the knowledge of cocoa yield development in the course of the harvest period, as well as the dynamics of pests and diseases are of great interest. Data from three different research activities of the mentioned project are analysed for yield development, the appearance, and the incidence of pests and diseases, where available. The research data are from: a) On-farm trials in multiple locations which were established in 2004. The performance of 16 cocoa varieties has been assessed for 3 years (2010–2012). b) Four high yielding cocoa farmers’ fields (2012 only). c) A long-term field experiment assessing the sustainability of five cocoa production systems (2011 and 2012). The trial investigates the influence of monocultures and different agroforestry systems under organic and conventional management on the yield development, among other agronomic, economic and environmental parameters
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