Stefanec, M.; Hofstadler, D. N.; Kaercher, M. H.; Schmickl, T.

Observing honeybee (Apis mellifera) brood dynamics and host-parasite interactions, especially within sealed cells, is vital for colony health research but traditionally relies on disruptive or destructive methods. Here we present BroodScan, a monitoring system employing a modified consumer-grade Charge-Coupled Device (CCD) flatbed scanner for continuous, high-resolution basal imaging of brood cells directly within an active beehive. Our experiments, conducted over a 35-day period, demonstrate BroodScan\'s capacity to track the complete honeybee brood development cycle from egg to adult emergence, yielding quantitative data such as an average egg stage duration of 72.93 (2.04 hours SD, n=58). Notably, the system provided detailed, time-lapse visual documentation of the complete intra-cellular reproductive cycle of the parasitic mite Varroa destructor within sealed worker cells, including the progression from foundress mite to multiple distinct offspring stages and their maturation. BroodScan offers a valuable, non-invasive tool that overcomes key limitations of previous techniques, opening new avenues for research into honeybee biology, colony health, and the impacts of diverse stressors like Varroa destructor, thereby promising to enhance our understanding and stewardship of these vital pollinators.