Interactions between penicillium mallochii and the endoparasitoid venturia canescens grav. (hymenoptera: ichneumonidae), and implications for combined biocontrol of ephestia kuehniella (zeller) (lepidoptera: pyralidae)

Abstract

The application of biological control agents in combination can result in synergistic, neutral or antagonistic interactions, depending on the concentrations of the agents, the timing of the application and the host species. Ephestia kuehniella is a prominent storage pest, and Venturia canescens is recognised as a significant biological control agent for E. kuehniella. Penicillium mallochii is a recently identified species with an impact on insects. This study presents the first information on the interaction between P. mallochii and the parasitoid V. canescens, and the combined biological control of E. kuehniella using these two different control agents. The aim of the study is to evaluate the direct effect of P. mallochii conidia and ethanol extract applications on E. kuehniella, and the fungus-parasitoid-host interaction in three stages. The study investigates the impact of V. canescens on infected host larvae, the effect of fungal infection on parasitized host larvae, and the interaction between fungus and adult parasitoids. The results indicate that P. mallochii had a negligible effect on the developmental parameters of E. kuehniella, but it did reduce the total number of eggs. In the interaction studies, it was observed that the adult emergence time increased in all scenarios; however, it was determined that the adult parasitoid longevity was extended only in the parasitization stage after the dose application and shortened in the other two stages. Effective time management and the application of correct interaction scenarios are important to prevent antagonistic interactions in interaction scenarios.