How long is a larva susceptible to AFB spores?

A larva is particularly susceptible to American Foulbrood (AFB) spores during a specific period of its development. When the larvae are newly hatched, they are highly vulnerable to the bacteria that cause AFB. This susceptibility lasts for about 48-72 hours after they are first fed by the adult bees.

In this context, the correct answer indicates that the larva remains susceptible for approximately 53 hours, which falls within the established range of vulnerability. This timeframe is critical because if larvae ingest AFB spores during this window, they can develop the disease. Understanding the duration of susceptibility helps beekeepers manage their colonies effectively, especially when monitoring for outbreaks of AFB and knowing when to take preventive actions like avoiding feeding infected brood or performing thorough inspections.

The incorrect options suggest either a shorter period (24 hours or 48 hours) or an impractical duration (72 hours), which do not align with the biological understanding of the disease's dynamics regarding larval development and susceptibility to infection.