Why is annual cleaning of nesting tubes recommended for mason bee management?

Answer

To prevent the buildup of parasitic mites or harmful fungi within reused tunnels

Because mason bees do not share food or interact closely in the nest, diseases spread differently than in hives; however, reusing uncleaned tubes allows mites and fungi to accumulate, harming the developing cocoons.

Why is annual cleaning of nesting tubes recommended for mason bee management?
insectbeeclassificationfamilyMason Bee