Les champignons entomopathogènes
More than 530 species of entomopathogenic fungi have been known, for more than a century for some of them. They are more abundant and diverse in the tropics than in other areas of the globe. The most important insect mycoses are myscardiniosis, cephalosporiosis, aspergillosis, and entomophtorosis. The first symptoms generally appear 4 days after the infection. Infection is either internal, through the guts, or by penetration through the external cuticle. In the latter case, first symptoms are gray or yellow stains on the body. Mycelium of the parasite invades the whole of the insect body, which gradually hardens, eventually resulting in the insect death. The mycelium develops then quickly, eventually forming white, ash-gray or green conidia, depending on the fungus species. The cases of Beauveria (=Botrytis) bassiana (Deuteromycetes, Botrytidae) and Metarrhizium (=Entomophtora) anisopliae (Siphomycetes, Entomophthorales) are taken as examples. Bio-pesticides based on entomopathogenic inocula include Boverine (a whitish powder containing 2-6 billion spores of B. bassiana per g), and Metarrhizium (a light green powder containing 1.5-3 billion spores of M. anisopliae per g), which cause respectively white and green myscardinioses in insects. The reasons which have hampered the use of entomopathogenic fungi as biological control agents are discussed.
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| Format: | conference_item biblioteca |
| Language: | fre |
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CIRAD
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| Subjects: | H10 - Ravageurs des plantes, champignon entomopathogène, agent de lutte biologique, biopesticide, http://aims.fao.org/aos/agrovoc/c_2587, http://aims.fao.org/aos/agrovoc/c_920, http://aims.fao.org/aos/agrovoc/c_27467, |
| Online Access: | http://agritrop.cirad.fr/478743/ http://agritrop.cirad.fr/478743/1/ID478743.pdf |
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