Phylogenetic analysis and biocontrol potential of entomopathogenic fungi against Tropinota (=Epicometis) hirta (Poda) (Coleoptera: Cetoniidae) and the apple scab disease Ventura inaequalis

Abstract

Background Entomopathogenic fungi have long been used as a biopeptide in the biological control of insect pests in agriculture, forestry and veterinary. At the same time, it is known that these fungi have positive effects on plant growth, health, and the antagonist effect against various plant pathogens. Entomopathogenic fungal isolation was performed from soil samples collected from apple orchards and Tropinota (=Epicometis) hirta (Poda) (Coleoptera: Cetoniidae) adults which is an important pest of fruit trees. The isolated fungi were identified at the species level by phylogenetic analysis based on multi-locus sequence approach using various gene sequences (ITS, rpb1, bloc, EF1-α and β-tubulin). The fungi obtained were tested against T. hirta and the apple scab disease, Ventura inaequalis under laboratory conditions. Results Three (Bz isolates) and 15 (AK isolates) entomopathogenic fungi (EPF) were isolated from T. hirta adults and 48 soil samples, respectively. The isolated fungi were identified as Beauveria bassiana (Bz-1, Bz-2, AK-10, AK-14, AK-17, and AK-18), Metarhizium robertsii (Bz-3, AK-4, AK-5, AK-6, AK-7, AK-8, AK-9, AK-11, AK-13, AK-15, and AK-16) and Metarhizium sp. (AK-12). All isolated fungi were tested against T. hirta adults, causing the same mortality but different mycosis values. In addition, the antagonistic effects of fungal isolates against V. inaequalis, the important apple pathogen, were determined and the highest effect was obtained from B. bassiana AK-10 with 69.3%. Conclusion This is the first study to determine the effectiveness of EPF against T. hirta and V. inaequalis, and the results obtained are thought to be useful for the biological control of both pests.