Lobesia botrana: A Biological Control Approach with a Biopesticide Based on Entomopathogenic Fungi in the Winter Season in Chile

SIMPLE SUMMARY: Lobesia botrana, also known as the European grapevine moth, is one of the main pests that affect grapes. In Chile, this type of moth is classified as a quarantine pest, which requires fumigating the fruit with methyl bromide to prevent the immature stages of the pest from being strained and reaching the export-destination countries. In the fields, the larvae of this moth feed on grapes, which can introduce diseases such as Botrytis cinerea, thereby increasing the costs of managing the crop. One way to control this pest is to use entomopathogenic fungi on the winter pupae to reduce moth populations in the spring. In the present study, six fungi were characterized, formulated, and evaluated. The selected strains RGM 2184 and RGM 678 were evaluated in two regions of Chile during two seasons. These strains reached maximum efficiencies of 80% and 88%, respectively. Therefore, the use of entomopathogenic fungi is an environmentally friendly alternative to control L. botrana and reduce the use of chemical pesticides. ABSTRACT: Lobesia botrana (Denis and Shiffermüller) (Lepidoptera: Tortricidae) is one of the main pests that affect the production and export of table grapes in Chile. Because this pest has quarantine status, the fruit must be fumigated with methyl bromide, which reduces the fruit’s export competitiveness in the destination market. In the present study, to help resolve this issue, six native entomopathogenic fungi were identified through multilocus analysis, including three Beauveria pseudobassiana and three Metarhizium robertsii. These fungi were evaluated in the laboratory to control L. botrana in its pupal stage in a silk cocoon and compared against a biological control product. Formulations with additional carbon sources improved the performance of the fungi. The treatments with outstanding performance contained the fungal strains B. pseudobassiana RGM 2184 and M. robertsii RGM 678. These strains were evaluated in the field during the winter season in two different regions of the country; the strains reached maximum efficacies of 80% and 88%, respectively, at 21 days post first application. Therefore, entomopathogenic fungi can contribute to reducing pupal populations in winter, thereby decreasing the moth population in spring–summer.