Nocturnal dispersal by female Acarapis woodi in honey bee (Apis mellifera) colonies

Comparisons were made between the infestation levels of the honey bee tracheal mite Acarapis woodi (Rennie) in newly emerged honey bees (Apis mellifera L.) exposed for 12 h during the daytime or nighttime in mite-infested bee colonies. Bees exposed during the night harbored a significantly higher number of mites (718) when compared with the daytime bees (88 mites) (n = 14 day/night cycles utilizing 33 colonies). On 4 days of an 8-day study, three test colonies were closed during the daytime to eliminate foraging flights. Thus equal numbers of bees were present in the colonies during the day and night sample periods. These 4 flightless days were compared to 4 free-flight days and mite dispersal rates were not significantly different.