Effective chemical for protecting hide glue from microbial attack
Silver salts are used to kill bacteria, algae and fungi.  Different types of clothing are 'laced' with silver to kill the bacteria that cause body odor.  Silver spoons were suspected historically to have self-sanitizing properties.  I ran a small analytical chemistry lab that was exempt from most emission oversight, but we could not dispose of silver waste into the sewer as it would destroy the 'good' bacteria at the water-treatment plant.  Different silver compounds, often phosphates, are used to strike a balance between required toxicity and durability/longevity.  If I were starting your project, I would at least start with a good literature search along these lines and some small scale proof-of-concept experiments if it seemed at all feasible.

I do want to be clear however, that I know of no reason to expect silver to be toxic to beetle larvae, at least not at the concentrations that would provide anti-microbial protection. Maybe you would need a second additive for that purpose