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Effective Biological Control Agent (effective + biological_control_agent)
Selected AbstractsA historical review of research on the weaver ant Oecophylla in biological controlAGRICULTURAL AND FOREST ENTOMOLOGY, Issue 1 2008Paul Van Mele Abstract 1,Although the weaver ant Oecophylla is the first written record of biological control, dating from 304 ad, there have been fewer than 70 scientific publications on this predator as a biological control agent in Asia, from the early 1970s onwards, and fewer than 25 in Africa. 2,Apart from crop-specific ecological and perceptual factors, a historical review shows that political and market forces have also determined the extent to which Oecophylla was incorporated into research and development programmes. 3,In Africa, research on weaver ants in biological control concentrated on export crops, such as coconut and cocoa, whereas, in Asia and Australia, research focused on fruit and nut crops, primarily destined for domestic markets. 4,Increased evidence of pesticide inefficiency under tropical smallholder conditions, changing paradigm shifts in participatory research and a growing scientific interest in local knowledge in the early 1990s opened up new avenues for research on conservation biological control. 5,Lobbying and advocacy have been needed to ensure that Oecophylla was recognized as an effective biological control agent. 6,With an increased market demand for organic produce, holistic approaches such as conservation biological control, particularly the use of Oecophylla, are increasing in importance. 7,Multi-stakeholder strategies for collaborative learning are proposed for a better control of major fruit, nut and timber tree pests in Africa, Asia and Australia. [source] Seasonal phenology of the gall-making fly Fergusonina sp. (Diptera: Fergusoninidae) and its implications for biological control of Melaleuca quinquenerviaAUSTRALIAN JOURNAL OF ENTOMOLOGY, Issue 4 2000John A Goolsby Abstract A gall-making fly, Fergusonina sp., is under study as a potential biological control agent of Melaleuca quinquenervia (Cav.) S. T. Blake, an invasive weed in Florida, USA. The seasonal phenology of Fergusonina sp. and its host M. quinquenervia was studied over 2 years in northern New South Wales and south-eastern Queensland. Fergusonina sp. populations followed an annual cycle, with gall numbers peaking in August/September. Gall density was strongly correlated with leaf bud density and temperature, but not rainfall. Comparison of climates in Australia across the native range of Fergusonina sp. with the climate of Miami, Florida, predicts that climate should not be a limiting factor in its establishment. The fly/nematode complex of Fergusonina/Fergusobia sp. is compared with other gall-making agents used in biological control programs. Galls are formed from primordial leaf bud and reproductive structures of the plant and have many of the attributes of a moderately powerful metabolic sink. High gall densities could potentially suppress seed production and reduce the vigour of the tree, which would make this insect species an effective biological control agent of M. quinquenervia. [source] Temperature and Ca2+ ion as modulators in cellular immunity of the Sunn pest Eurygaster integriceps Puton (Heteroptera: Scutelleridae)ENTOMOLOGICAL RESEARCH, Issue 6 2009Arash ZIBAEE Abstract Environmental conditions in addition to divalent cations may affect the interactions between pathogens and insects. Elucidation of factors which modulate insect immune responses could be a significant part of investigations in this area. In this study, adults of Eurygaster integriceps, as the destructive pest of wheat, were kept at different temperatures in addition to injection with different concentrations of Ca2+ to find the effect on cellular immune reactions against Beauveria bassiana. Results showed that total and differentiate hemocyte numbers, nodule formation and phenoloxidase activity increased with elevation of temperature so that the higher values were obtained at 30 and 40°C at various intervals. Higher concentrations of Ca2+ ion (5 mM) caused an increase in plasmatocyte length and width especially after 60 min. Similar results were observed for nodule formation and phenoloxidase activity of E. integriceps adults after injection by B. bassiana spores and phenoloxidase activity. It is clear from the current study that thermoregulation and Ca2+ ion can positively affect the hemocyte numbers especially plasmatocytes and granulocytes, nodule formation and phenoloxidase activity in E. integriceps. The understanding of modulators of the insect immune response may directly influence novel approaches to obtain safe and effective biological control agents. [source] Bacteria used in the biological control of plant-parasitic nematodes: populations, mechanisms of action, and future prospectsFEMS MICROBIOLOGY ECOLOGY, Issue 2 2007Baoyu Tian Abstract As a group of important natural enemies of nematode pests, nematophagous bacteria exhibit diverse modes of action: these include parasitizing; producing toxins, antibiotics, or enzymes; competing for nutrients; inducing systemic resistance of plants; and promoting plant health. They act synergistically on nematodes through the direct suppression of nematodes, promoting plant growth, and facilitating the rhizosphere colonization and activity of microbial antagonists. This review details the nematophagous bacteria known to date, including parasitic bacteria, opportunistic parasitic bacteria, rhizobacteria, Cry protein-forming bacteria, endophytic bacteria and symbiotic bacteria. We focus on recent research developments concerning their pathogenic mechanisms at the biochemical and molecular levels. Increased understanding of the molecular basis of the various pathogenic mechanisms of the nematophagous bacteria could potentially enhance their value as effective biological control agents. We also review a number of molecular biological approaches currently used in the study of bacterial pathogenesis in nematodes. We discuss their merits, limitations and potential uses. [source] | ||||||||||