Epizootia do fungo entomopatogênico Moelleriella Bres. sp. sobre mosca-branca e cochonilha: primeiro registro, avaliação do potencial biológico e desenvolvimento in vitro

Abstract

The use of entomopathogenic fungi as biological control agents represents a sustainable alternative to the use of agrochemicals in agriculture. In this context, the genus Moelleriella (Clavicipitaceae, Hypocreales, Ascomycota) has been little studied, despite its potential for controlling insect pests, such as whiteflies and mealybugs, and its potential as an endophyte of associated plants. The present study aimed to evaluate the growth of colonies, conidial production, and germination of Moelleriella sp. in different culture media under laboratory conditions. To this end, the fungus was isolated from infected insects in a remnant of the Atlantic Forest in Brazil, morphologically identified, and cultured on five culture media (AN, MEA, SAB, BDA, and YEAST). Radial colony growth, conidial production, and germination percentage were evaluated. The data were analyzed using analysis of variance (ANOVA) and Tukey’s test (α = 0.05). The results showed significant differences among treatments, with the Yeast Extract (YEAST) medium standing out for promoting the highest mycelial growth, as well as the highest conidia production and germination (F₄,₄₀ = 71.22; p < 0.001). These results suggest that the nutritional composition of the medium, particularly its content of carbon and nitrogen sources, directly influences the physiological performance of the fungus. In conclusion, Moelleriella sp. shows high potential as a biological control agent, and the YEAST medium stands out as an efficient alternative for its production under laboratory conditions. This study provides relevant information for optimizing cultivation systems and lays the groundwork for future research aimed at its application in Integrated Pest Management programs.