Viruses are noncellular forms of life infecting all known cellular organisms, among them are honey bees, which play a crucial role in maintaining biodiversity by pollinating various plants. Bee viruses can infect other insects as well and spread in various ways – the role of plants in the spreading of insect viruses is not yet well established. During this work, using modern molecular biology, microbiology, and metagenomic methods the viruses distributed on honey bee-pollinated plants and bees will be evaluated; an attempt will be made to establish the role of plants in their spreading among insects. Lately, various ecologically and human-friendly alternative antimicrobial agents are being researched. Of these, plant-based compounds and extracts, e.g. essential oils, are in focus. Their antiviral mode of action is not yet very well understood. In this work, by using yeast RNA viruses and other model systems the antiviral activity and action mechanisms of plant extracts and their constituents will be investigated. By analyzing the data on viral spread in bees and plants and the antiviral activity of plant-based substances, an assessment of the importance of plants in the transmission of viruses and the prevention of viral diseases will be made.