Resumo

LOPEZ BLANCO, Carlos. Pathogenicity of Beauveria bassiana about Hypothenemus hampei in reproductive generations. Apthapi [online]. 2017, vol.3, n.3, pp. 639-651. ISSN 0102-0304.

The present study was carried out at the Coroico Experimental Station, San Pedro de la Loma, municipality of Coroico, during the year 2013. The objective of the study was to determine the pathogenicity of Beauveria bassiana strains on Hypothenemus hampei in four successive crops. The variables studied were conidiation in substrates and viability of conidia, degree of pathogenicity and virulence of fungus strains. The production of conidia in rice substrate was developed. The pathogenic test was performed in a laboratory bioassay for 12 days under the Completely Random Design with 4 treatments (strains 13, 24, 9205, Witness), 3 replicates, inoculated to the drills by immersion for 3 minutes in a concentration 1 x 10⁷ c.ml¹ fungicide and the Sterile Distilled Water (ADE) control, individually confined to vials. As a result of the study, strains 9205 and 13showed higher conidia production in relation to strain 24, in conidia viability the strains did not present significant differences, exceeding 90% of germination in the different replicates. Regarding pathogenicity there are significant statistical differences in the mode of action of fungus strains on the borer, with high mortality of the strains up to replicates 1 and 2, rescuing the strain 13 in replícate 3. The virulence of strains showed a gradual loss in the successive cultures, with high aggressiveness in replicates 1 and 2, in terms of daily mortality and mean lethal time (TL50), rescuing strain 13 and 9205 in replícate 3 prior validation, discarding strain 24 and replication 4 for application in the field.

Palavras-chave : Pathogenicity; virulence; strains; conidia; viability.