Biological control of Oligia latruncula (Denis & Schiffermüller, 1775) using Cladosporium sp.: evaluation of virulence and efficacy

Entomopathogenic fungi are important microbial agents that help keep agricultural and forest pests below the economic damage threshold. In August 2023, spontaneously dead and infected with Cladosporium sp. sclerotic bodies of Oligia latruncula (Denis & Schiffermüller, 1775) larvae were found in the grass field in Erzurum, Türkiye. Phylogenetic analysis showed that the Turkish isolate of Cladosporium sp. clustered with the Brazilian isolate. The third instar healthy O. latruncula larvae were sprayed with five different doses of fungus (2,3 × 10⁵ to 2,3 × 10⁹ conidia/mL^− 1) and the mortality rate at the end of 14 days was determined as 100% for the highest dose. As a result of this experiment, it was determined that the LD₅₀ value was determined to be 2.87 × 10⁵ conidia/ mL^− 1. In this study, for the first time, an entomopathogenic fungus was isolated from the larvae of the grass pest O. latruncula, and its virulence was demonstrated. This identified an effective and important microbial agent for the biocontrol of harmful larvae. This study will shed light on further studies to develop a new mycoinsecticide through the mass production of Cladosporium sp. against O. latruncula larvae.