Resumo

CERNA-CHAVEZ, Ernesto et al. Activity of plants extracts and entomopathogenic fungi for the control of the guava weevil (Conotrachelus dimidiatus Champion) Coleoptera: Curculionidae. Biotecnia [online]. 2021, vol.23, n.1, pp.70-76.  Epub 18-Jun-2021. ISSN 1665-1456.  https://doi.org/10.18633/biotecnia.v23i1.1335.

The guava weevil is the main phytosanitary problem, causing production losses of up to 60 %. The main control method of the guava weevil is the application of chemical insecticides such as methyl parathion and malathion. The objective of the study was to evaluate the efficiency of entomopathogenic fungi in combination with different plant extracts in the control of Conotrachelus dimidiatus under laboratory conditions. We evaluated the biological effectiveness of Beauveria bassiana and Metarhizium anisopliae native strains, the susceptibility of the guava weevil to vegetable extracts (pepper and jicama seed), as well as the compatibility of B. bassiana and M. anisopliae with the vegetable extracts for weevil control. The strains LC50 was calculated, from the strains that presented greater pathogenicity on adults of C. dimidiatus, later these were exposed to the LC50 and sublethal concentrations of the extracts. The results showed that the B. bassiana strains were pathogenic for the insect. Pepper extract and jicama seed showed insecticidal activity. Mixtures between fungi and extracts recorded mortalities of 90 %.

Palavras-chave : LC50; sublethal concentration; B. bassiana; M. anisopliae; mortality; Pachyrhizus erosus and Piper nigrum.