Commercial strains of entomopathogenic fungi allied to sustainable agriculture: the case of Persian lime

Abstract

This study evaluates the efficacy of commercial strains of entomopathogenic fungi for controlling D. citri nymphs on lemon plants under greenhouse conditions. Three commercial strains—Metarhizium anisopliae (Metschnikoff) Sorokine, Isaria javanica (Bally) Samson & Hywel-Jones—and a mixture of both were tested, applied at a concentration of 1 × 10^7 conidia/mL at an average temperature of 19.6 ± 2 °C. The results show an effect of the commercial strains on nymph mortality and high treatment efficacy, with mortality rates exceeding 98%. Although the use of commercial strains could be considered a limitation, it is important to assess the efficacy of products already available on the market, beyond the laboratory trials required for their sale. Greenhouse evaluation offers an approach that more closely approximates potential field outcomes. The mortality recorded in this study is comparable to that caused by synthetic pesticides used in Mexico for D. citri control, but without their adverse effects on human health. Persian lime (Citrus latifolia Tanaka) is among the most profitable crops in Mexico in terms of production and export chains, yet it is frequently and severely affected by the vector of Huanglongbing disease (Diaphorina citri Kuwayama). In recent years, this pest has developed high resistance to synthetic insecticides; therefore, rotating toxicological groups and incorporating biological control agents are recommended. The treatments evaluated exhibit efficient pathogenicity against D. citri and contribute to reducing the use of conventional chemical products. The use of biological agents such as M. anisopliae and I. javanica in agriculture could help Mexican producers meet the growing demand for environmentally friendly, sustainably produced goods and increase export opportunities.