Etude du Ribovirus de Latoia viridissima Holland ravageur de palmacées en Afrique de l'Ouest. Caractérisation - Diagnostic sérologique - Suivi épidémiologique

Zeddam Jean-Louis, Philippe René, Veyrunes J.C., Fédière Gilles, Mariau Dominique, Bergoin M.. 1990. Etude du Ribovirus de Latoia viridissima Holland ravageur de palmacées en Afrique de l'Ouest. Caractérisation - Diagnostic sérologique - Suivi épidémiologique. Oléagineux, 45 (11) : 493-500. International Conference on Palms and Palms Products for the 50th Anniversary Celebration of NIFOR, Benin City, Nigeria, 22 Novembre 1989/25 Novembre 1989.

Titre anglais : Study of the Ribovirus of L. viridissima Holland, a palm pest in West Africa. Characterization - Diagnosis - Serology and epidemiological monitoring

Résumé : Une revue des entomopathogènes locaux régulant les populations naturelles de Latoia viridissima a montré que l'agent de contrôle le plus efficace était un virus. Afin de détecter rapidement et à faible coût ce ribovirus, appelé LvV, dans les échantillons biologiques, un test immunoenzymatique (ELISA) a été mis au point. A l'aide de cet outil, on a pu étudier l'aspect épidémiologique de la maladie dans les plantations de palmiers à huile. Le suivi mené sur le terrain durant trois mois au cours de deux pullulations successives de L. viridissima a précisé l'incidence de la virose à l'émergence des jeunes chenilles, son évolution au cours des différents stades larvaires et son impact sur la démographie du ravageur. Par ailleurs, le clonage moléculaire du génome viral a été entrepris

Résumé (autre langue) : Caterpillars of the Limacodid lepidopteran Latoia viridissima (Bolland 1893) are one of the main leaf-eating palm pests in Côte d' Ivoire. A previous review of the local entomopathogens regulating natural populations of this pest showed that the most effective control agent was a virus. A physico-chemical characterization of the virus responsible for the epizootics indicates here several of its basic properties, including type of genome (single-stranded polyandenylated RNA), clearly indicating its resemblance to the picornaviruses. However, its particular polypeptidic composition distinguishes it from some members of this family currently found in insects, members with which, incidentally no antigenic relationship has been detected. In order to detect this ribovirus, known as LvV, rapidly and cheaply m biological samples an immuno-enzymatic test has been developed (ELISA), which brings into play the sandwich technique. The minimum sensitivity thresholds for the test were established for the purified virus and for the virus found in host tissue Using the serological diagnosis tool it was possible to investigate the epidemiological aspect of the disease developing on a plantation Monitoring in the field for three months during two successive L. viridissima outbreaks provided precise details of virosis incidence as young larvae emerged. Its development at different instats and its impact on the pest population In addition, molecular cloning of the viral genome has been undertaken and provides the first indications of how LvV RNA is organized. Using the complementary DNA part obtained in this way, different types of nucleic probes have been manufactured, involving radioactive markers or biotinylated nucleotides. The ability of these various probes, with either double-stranded DNA or single-stranded RNA (ribo-probes), to detect the viral RNA bas been tested.

Mots-clés Agrovoc : Elaeis guineensis, virus des invertébrés, lutte biologique, insecte nuisible, diagnostic, Clonage moléculaire, technique immunoenzymatique

Mots-clés géographiques Agrovoc : Afrique occidentale

Mots-clés complémentaires : Latoia viridissima

Classification Agris : H10 - Ravageurs des plantes

Auteurs et affiliations

• Zeddam Jean-Louis
• Philippe René
• Veyrunes J.C.
• Fédière Gilles
• Mariau Dominique
• Bergoin M.

Source : Cirad - Agritrop (https://agritrop.cirad.fr/437259/)

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