Examinando por Materia "Beauveria bassiana"

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  • Miniatura
    PublicaciónAcceso abierto
    Alternative hosts and standardization of methods to evaluate the biocontrol activity of mycoinsecticides.
    (Universidad del Valle, 2020-12-26) Torres Torres, Lissette; Espinel Correal, Carlos; Santos Díaz, Adriana Marcela; Sociedad Colombiana de Entomología - Socolen; Universidad del Valle; Montoya Lerma, James
    The entomopathogenic fungi Metarhizium anisopliae (Ascomycota: Clavicipitaceae) and Beauveria bassiana (Ascomycota: Cordycipitaceae) are an alternative for the control of grassland pests (e.g. Rhammatocerus schistocercoides (Orthoptera: Acrididae) and soybean pests (e.g. Cerotoma tingomariana; Coleoptera: Chrysomelidae). To use these microorganisms as active principles of micoinsecticides, it is necessary to have quality control methods (microbiological, physicochemical and biological activity) accuracy, and reproducibility in a given timeframe. For this reason and given the difficulty in obtaining individuals in the field and in the establishment of the rearing of R. schistocercoides and C. tingomariana, we established methods for the routine evaluation of biological activity using alternative hosts. For M. anisopliae directed to the control of R. schistocercoides, the model insects Diatraea saccharalis (Lepidoptera: Crambidae) and Spodoptera frugiperda (Lepidoptera: Noctuidae) were tested, and for B. bassiana directed to the control of the target insect C. tingomariana, the model insects D. saccharalis and Chloridea virescens (Lepidoptera: Noctuidae) were evaluated. D. saccharalis and C. virescens were selected as alternative insects to evaluate the efficacy of M. anisopliae and B. bassiana, respectively. Efficacy was close to 80 % for both pathogens. The methods with the selected alternative insects were standardized and showed that they are repeatable and reproducible under the evaluated conditions
  • Miniatura
    PublicaciónAcceso abierto
    Efficacy of entomopathogenic fungi to control Leptopharsa gibbicarina (Hemiptera: Tingidae) in oil palm.
    (Universidad del Valle, 2016-06-30) Barrios T., Carlos Enrique; Bustillo P., Alex Enrique; Ocampo R., Kely Lorena; Reina C., Miguel Angel; Alvarado M., Hanna Lorena; Sociedad Colombiana de Entomología - Socolen; Universidad del Valle
    Leptopharsa gibbicarina, is considered an economically important pest in Colombian oil palm plantations. Experiments on pathogenicity and virulence of the fungus Beauveria bassiana (CPBb0404) Isaria fumosorosea (CPIf1001) and Purpureocillium lilacinum (CPPl0601) were evaluated on L. gibbicarina adults coming from a rearing unit. Pathogenicity of isolates was tested in laboratory. Adults of L. gibbicarina were individualized in Petri dishes and sprayed with 0.2 ml of a suspension of 1 x 107 conidia/ml. Virulence was evaluated in two stages under a shade house, first palm leaves were infested with L. gibbicarina adults, and treatments were sprayed at a dosage of 1 x 1013 conidias/ ha, then were tested at different dosages (5 x 1012, 1 x 1013 and 1.5 x 1013 conidia/ ha). Finally a field experiment was conducted to test field efficacy. Results of laboratory experiment showed that the three fungi are pathogenic to L. gibbicarina (> 96% mortality). In the virulence test, I. fumosorosea, B. bassiana and P. lilacinum caused mortalities of 74.3%, 92.8% and 100%, respectively, being statistically significant differences (P = 0.05). However, when different dosages were tested, no statistical differences were found. Fungi then were evaluated under oil palm plantation conditions, and no significant statistical differences were detected. This study allows to recommend P. lilacinum to be applied in an integrated pest management program to control L. gibbicarina, due to its high virulence (> 80%) and quality control attributes in commercial production.
  • Miniatura
    PublicaciónAcceso abierto
    Fungi associated with Hypothenemus hampei (Coleoptera: Curculionidae: Scolytinae) in Tabasco, Mexico.
    (Universidad del Valle, 2019-12-31) Torres de La Cruz, Magdiel; Gerónimo Torres, José del Carmen; Ortiz García, Carlos Fredy; Ayala Escobar, Victoria; Pérez de La Cruz, Manuel; Cappello García, Silvia; Sociedad Colombiana de Entomología - Socolen; Universidad del Valle; Montoya Lerma, James
    In the state of Tabasco, Mexico, the coffee berry borer Hypothenemus hampei, was reported for the first time in 2004. Since then it has become the main insect pest of coffee in this area. The aim of the present study was to document the mycobiota associated to H. hampei adults in coffee plantations of three localities of Tabasco: Teapa, Tacotalpa and Huimanguillo. Coffee berries infested with the coffee berry borer were collected from the field and adults of H. hampei were extracted. The fungi that grew on the Scolytinae cadavers were isolated and identified using taxonomic keys. Two isolates of each morphological species were molecularly identified. A total of 74 isolates was obtained from the cuticle of H. hampei. Of them, 52 presented morphological affinity with Fusarium solani, five with F. oxysporum, five with F. verticillioides, one with Geotrichum candidum and 11 with Beauveria bassiana. The DNA sequences showed similarity with sequences found in GenBank, with homologies of 99 % and 100 %, which coincided with each morphological species. The most abundant species was F. solani (70.2 %), followed by B. bassiana (14.8 %). The species F. verticillioides and F. oxysporum represented each one, at 6.7 %, respectively. The least abundant was G. candidum (1.3 %). The findings of the species F. verticillioides and G. candidum are new reports of micromycetes fungi associated with H. hampei. This study contributes to the knowledge of the diversity of fungi associated with H. hampei.