DNA barcoding of Penicillium mallochii and its interactions with the parasitoid Venturia canescens in sustainable biological control

The combination of fungal biological control agents and parasitoids enhances the effectiveness in pest management. This study presents initial information on the interaction between Penicillium mallochii and the parasitoid Venturia canescens, as well as their combined biological control against Ephestia kuehniella. Initially, developmental biology studies were conducted by applying different doses of P. mallochii metabolites and conidial suspension on storage pests E. kuehniella and Cadra cautella, revealing the presence of fungal insecticidal activity and its egg-reducing effect. Additionally, it was determined that the fungus does not produce mycotoxins and does not exhibit genotoxic and cytotoxic effects at low doses (below 0.708 mg/mL). In immune parameter studies, it was found that P. mallochii triggers the production of antimicrobial peptides in E. kuehniella hemolymph after 24 and 48 hours. Total hemocyte count studies showed that larvae initially enhance their immune defense by synthesizing new hemocytes, but defense weakens over time. Interaction studies were conducted under three different scenarios (post-parasitization dose application, dose after parasitization, and dose application to adult parasitoids) to assess the effect of the fungus on the pre-adult development of the parasitoid, parasitoid survival time, and the preference of parasitoids for larvae treated with fungus metabolite and conidia at different application times (1st, 4th, and 8th day). Among the scenarios, it was determined that post-parasitization dose application was effective, particularly with conidial suspensions at 105 conidia/mL and metabolite applications at concentrations of 0.1 or 0.5 mg/mL, as viable and effective doses for P. mallochii's biological control efforts.