Factors Influencing the Lifespan of Bees 239 



cannot rear a brood unless vitamins are added to their diet. 

 In such vitamin-starved bees addition of pantothenic acid 

 or a mixture of vitamins to the diet will restore normal brood- 

 rearing within 24 hours. 



Apparently the newly emerged young bee is left with large 

 body reserves of vitamins, thus making it possible to develop 

 its pharyngeal glands, lengthen its lifespan and rear one 

 brood-generation in spite of consuming a protein-rich but 

 vitamin-free diet. It seems, however, that this vitamin 

 reserve is not sufficient to pass on to the brood an adequate 

 vitamin surplus; so that the second generation of vitamin- 

 starved bees shows signs of vitamin deficiency, i.e. the 

 development of the pharyngeal glands and the lifespan are 

 affected. Similarly, a colony of bees kept on a protein-free 

 diet are able to raise one generation of normal brood by using 

 up their own protein reserves (Haydak, 1935). 



Discussion 



Present-day knowledge of the inter-efFects of nutrition, 

 physiological condition and lifespan of the bee, and of the 

 processes of life in the colony throughout the year, can be sum- 

 marized as follows: 



(1) Pollen is the main source for protein, vitamins, and 

 minerals, and therefore forms, with the sugar-containing 

 juices, the basis of nutriment and development of the bee 

 colony. Pollen-feeding of the young bee promotes the develop- 

 ment of the pharyngeal and wax glands, the formation of a 

 many-layered fat body and an increase in lifespan. Of all the 

 pollen substances proteins are the most decisive in influencing 

 the lifespan and physiological condition of the bee. For the 

 adult bee vitamins in food are less essential as it still has a 

 large store of vitamins from the larval phase. Absolutely 

 essential is the extra vitamin supply at the time of brood- 

 rearing. There is a statistically comprehensible correlation 

 between physiological condition and lifespan. 



(2) The yearly cycle of life in the bee colony may be 



