Abstract

VALLE-RAMIREZ, Segundo Benedicto et al. Isolation and characterization of Metarhizium spp. of sugar cane crops and their pathogenicity against Mahanarva andigena (Hemiptera: Cercopidae). Cienc. Tecnol. Agropecuaria [online]. 2022, vol.23, n.1, e2361.  Epub Dec 31, 2021. ISSN 0122-8706.  https://doi.org/10.21930/rcta.vol23_num1_art:2361.

Metarhizium anisopliae is one of the most commercialized entomopathogenic fungi for the regulation of insect pest populations. The native strains of this fungus play an important role in natural control. However, its effectiveness in the conditions of the Ecuadorian Amazon is unknown. Accordingly, this research aimed to isolate and characterize native strains of M. anisopliae with the potential to control Mahanarva andigena (Jacobi) in sugar cane (Saccharum officinarum L.) crops. Collections were made for the isolation and characterization of the fungi, obtaining a total of 20 isolates (15 from soil samples and five from mycosed nymphs of M. andigena). All isolates were characterized based on their morphological and physiological characters. In ten of them, the pathogenicity against nymphs of M. andigena was assessed under laboratory conditions. Results obtained from the characterization of the isolates were variable, including the diameter and growth rate, conidia length and width, germination, spo rulation, and corrected mortality. The analysis of these characteristics demonstrated that isolates DSA5401 and TI6301 showed the best values for most of the variables evaluated, especially diameter, growth rate, and conidia production. Regarding control effectiveness, isolates DAS5401, TI6301, TS6304, PS5003, SJS5104, and SJS5102 presented high corrected mortality. These results indicate the effectiveness of native M. anisopliae isolates for their use in biological control programs of M. andigena.

Keywords : biological insecticides; biological pest control; conidia; pests of plants; sugar crops.

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