In vitro selection of a fungal pathogen for use against Diaphorina citri

•Diaphorina citri is an important pest that transmits the disease HLB in citrus.•Entomopathogenic fungi may provide an important control strategy for D. citri.•Growth, germination and sporulation of 16 isolates were assessed.•Four isolates from different species showed greatest potential.

The Asian citrus psyllid (ACP), Diaphorina citri, is an important pest of citrus, which transmits the disease Huanglongbing (HLB) and has had devastating effects on the citrus industry around the world. Control relies mainly on synthetic pesticides, but biological control using entomopathogenic fungi may provide an alternative strategy. We evaluated sixteen fungal isolates in total; three of Beauveria bassiana, two of Metarhizium anisopliae, three of Isaria fumosorosea (Group 1); and eight isolates of Hirsutella citriformis (Group 2). The in vitro growth, germination (after different incubation times) and sporulation were assessed for all isolates at four temperatures: 20, 25, 30 and 35 °C. Overall, the Group 1 isolates achieved the greatest growth, germination rate and sporulation compared with the H. citriformis isolates In Group 2. Among the Group 1 isolates, B1, M2 and I1 had the greatest performance in the biological attributes evaluated. Group 2 isolates were not competitive under in vitro assessment; however, they cannot be dismissed entirely until in vivo experiments are done as this species was the most common pathogen infecting ACP in the field.

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