Cannibalism and Brood-Rearing Efficiency in the Honeybee

SummaryDuring 34 continuous observations of hive entrances averaging 7 hours a day, 3% of brood disappeared from 5539 cells recorded. No brood or parts of brood could be found in the hive, and none were seen being carried out of it. It is therefore concluded that the brood that disappeared was eaten by the workers.Records of 6606 eggs and the individuals arising from them showed that the youngest brood was most likely, and the oldest least likely, to be eaten. There were significant differences between spring, summer and autumn. Brood survived to emergence of the adult at 75–80% in spring, 80–90% in summer, and 50–75% in autumn. Significantly more drone brood than worker brood was eaten. Similar survival rates were found (for worker and for drone brood) in queenright and queenless colonies in spring and summer, but in autumn, significantly more of both survived in queenless (75%) than in queenright (50–65%) colonies. Thus, by dequeening a colony in autumn, its efficiency in drone rearing could be raised to that in spring and summer. Survival rate of brood, resulting from the action of sex alleles, should be tested on very young brood.