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Cordyceps cateniannulata, a novel entomopathogenic fungus to control Stenoma impressella Busck (Lepidoptera: Elachistidae) in Colombia
Author(s) -
MontesBazurto Luis Guillermo,
BustilloPardey Alex Enrique,
MedinaCárdenas Héctor Camilo
Publication year - 2020
Publication title -
journal of applied entomology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.795
H-Index - 60
eISSN - 1439-0418
pISSN - 0931-2048
DOI - 10.1111/jen.12818
Subject(s) - biology , bioassay , conidium , beauveria bassiana , hypocreales , entomopathogenic fungus , biological pest control , horticulture , metarhizium anisopliae , lepidoptera genitalia , bassiana , botany , cordyceps , veterinary medicine , ecology , medicine , ascomycota , biochemistry , gene
Stenoma impressella is one of the most important defoliator pests in oil palm plantations in Colombia. To identify an alternative method for its control was characterized biologically and molecularly two strains of Cordyceps cateniannulata (CPIsp1201 and IPIsp1201) and three strains of Beauveria bassiana (CPBb0502; CPBb0411; CPBb0404) against S. impressella larvae. Virulence was evaluated under laboratory conditions. In an oil palm leaflet, individual larvae obtained from the insect colony were inoculated with 5 μl of a conidial suspension containing 1 × 10 7 conidia/ml. The five strains were pathogenic against S. impressella larvae. CPIsp1201 and IPIsp1201 strains resulted in the highest mortality and were subsequently evaluated in two bioassays using a dose of 1 × 10 13 conidia/ha. In the first bioassay, performed under shaded conditions, leaves of oil palms were infested with 75 larvae from the breeding/treatment. The second bioassay was performed in the field using natural populations. No differences were found between strains in both bioassays and the different dosages (5 × 10 12 , 1 × 10 13 , and 1.5 × 10 13 conidia/ha). Finally, the two strains were evaluated under oil palm plantation conditions at a dose of 1 × 10 13 conidia/ha in 126 naturally infested palms. Larval mortality caused by the strains IPIsp1201 and CPIsp1201 (79.5% and 70.5%, respectively) was higher than the natural mortality registered in the control (37.3%). Cordyceps cateniannulata used at 1 × 10 13 conidia/ha was effective at controlling S. impressella .