Potential of an entomopathogenic fungus from the Cladosporium cladosporioides species complex for aphid control: insights from biological parameters and bioassays

Aphids are a significant pest in many cultivated plants. However, there are few biological alternatives on the market that can effectively control them. The objective of this study was to analyze the effectiveness of an isolated entomopathogenic fungus in controlling the green peach aphid, Myzus persicae (Sulzer) (Hemiptera: Aphididae), and the cabbage aphid, Brevicoryne brassicae (L.) (Hemiptera: Aphididae). A native strain of the entomopathogenic fungus was isolated from a farm experiencing an epiphytic outbreak, where approximately 40% of the M. persicae population was infected. This strain was identified as a member of the Cladosporium cladosporioides species complex. Laboratory bioassays were conducted to estimate the mean lethal concentration (LC50) and to evaluate biological parameters such as optimal temperature for colony growth, conidia production under different photoperiods, and enzymatic activity. It was determined that this strain has an LC50 of 1.51 × 106 conidia ml−1 for M. persicae and 1.85 × 104 conidia ml−1 for B. brassicae. The fungus exhibits optimal growth at temperatures between 16 and 22 °C, with no significant differences in conidia production under varying photoperiod conditions. Additionally, strong lipase activity, moderate protease activity, and weak chitinase activity were confirmed in this fungus. This research demonstrates that the isolated strain can control both aphid species in laboratory trials and could be considered a potential candidate for commercial use.