Galleria mellonella and the Bac-to-Bac Expression System: A Convenient Model for Testing Molecules Intended to Genetically Enhance Baculovirus Pathogenicity.

The use of viruses as natural pathogens of pest insects is a promising approach in biocontrol. The main drawback of this approach is its relatively slow mode of action, which could be addressed through genetic modifications of the strains used. In this article, we propose the use of the commercially available Bac-to-Bac system for infecting pest insects with a recombinant virus and assessing the impact of various molecules on their viability. Using the laboratory-friendly model organism Galleria mellonella and baculovirus carrying the eGFP gene, we demonstrated a 100% infection rate, with a consistent and stable spread of the viruses throughout insect bodies and a gradual increase in recombinant protein expression. Notably, at day 5 post-infection the insects remained viable and active. This approach enables the identification of pathogenic effects caused by the virus-induced expression of other molecules, such as toxins.