Associations between reproduction and work in workers of the Asian hive bee Apis cerana.
If a honey bee (Apis spp.) colony becomes queenless, about 1/3 of young workers activate their ovaries and produce haploid male-producing eggs. In doing so queenless workers maximize their inclusive fitness because the normal option of vicarious production of relatives via their queen's eggs is no longer available. But if many workers are engaged in reproduction, how does a queenless colony continue to feed its brood and forage? Here we show that in the Asian hive bee Apis cerana hypopharyngeal gland (HPG) size is larger in queenless workers than in queenright workers and that bees undertaking brood-rearing tasks have larger HPG than same-aged bees that are foraging. In queenless colonies, workers with a smaller number of ovarioles are more likely to have activated ovaries. This reinforces the puzzling observation that a large number of ovarioles reduces reproductive success in queenless A. cerana. It further suggests that reproductive workers either avoid foraging or transition to foraging later in life than non-reproductive workers. Finally, our study also showed that ovary activation and larger-than-average numbers of ovarioles had no statistically detectable influence on foraging specialization for pollen or nectar.
Laboratory of Tropical Forest Ecology, Xishuangbanna Tropical Botanical Garden, Chinese Academy of Science, Kunming, Yunnan Province 650223, China; Eastern Bee Research Institute of Yunnan Agricultural University, Heilongtan, Kunming, Yunnan Province 650201, China. Electronic address: kentan@xtbg.ac.cn.
Ken
K
Tan
Eastern Bee Research Institute of Yunnan Agricultural University, Heilongtan, Kunming, Yunnan Province 650201, China.
Yuchong
Y
Wang
Eastern Bee Research Institute of Yunnan Agricultural University, Heilongtan, Kunming, Yunnan Province 650201, China. Electronic address: 850143087@qq.com.
Shihai
S
Dong
Eastern Bee Research Institute of Yunnan Agricultural University, Heilongtan, Kunming, Yunnan Province 650201, China. Electronic address: liuxiwen1345890@163.com.
Xiwen
X
Liu
Eastern Bee Research Institute of Yunnan Agricultural University, Heilongtan, Kunming, Yunnan Province 650201, China. Electronic address: zhuangdidshyy@126.com.
Di
D
Zhuang
Eastern Bee Research Institute of Yunnan Agricultural University, Heilongtan, Kunming, Yunnan Province 650201, China. Electronic address: chenweiwen1989@yeah.net.
Weiwen
W
Chen
Behaviour and Genetics of Social Insects Laboratory, School of Biological Sciences A12, University of Sydney, NSW 2006, Australia.
Benjamin P
BP
Oldroyd
D000818:Animals; D001070:Appetitive Behavior; D001516:Bees / Q000254:growth & development / Q000502:physiology*; D005260:Female; D008297:Male; D010053:Ovary / Q000254:growth & development; D057048:Plant Nectar; D011058:Pollen; D012098:Reproduction / Q000502:physiology; D012919:Social Behavior
D057048:Plant Nectar
Apis cerana; Foraging behavior; Hypopharyngeal gland; Ovary activation