238 Anna Maurizio 



have taken place on the relationship between lifespan and 

 physiological condition in the adult bee, and to what ex- 

 tent it is influenced by the proteins and vitamins of pollen. 

 It must be pointed out that this concerns only the vitamin 

 requirements of the adult bee, as there are no doubts about the 

 vitamin requirements of the brood. 



The results of the experiments carried out so far can be 

 summarized as follows (Back, 1956, 1959; Freudenstein, 

 1958; de Groot, 1953; Haydak and Vivino, 1950, Koch and 

 Schwarz, 1956; Maurizio, 1954; Miissbichler, 1952; Pain, 

 1951a, b). In the caged young bee lifespan and physiological 

 condition are closely related to the protein content of food. 

 Bees fed exclusively on devitaminized casein develop pharyn- 

 geal glands, fat bodies and ovaries, and a statistically proved 

 increase of lifespan is observed by comparison with bees of the 

 same age fed on a pure sugar diet. An increase in nitrogen and 

 in dry weight occurs in the young bee if it is fed from its 

 emergence onwards on synthetic food — a mixture of sugar and 

 pure amino acids (de Groot, 1953). Addition of any one of the 

 vitamins (B^, Bg, Bg, nictotinic and pantothenic acids) 

 resulted in no statistically proved increase in lifespan, but 

 addition of vitamins to a protein-containing diet influenced 

 the development of the pharyngeal and wax glands. Although 

 young bees can develop their pharyngeal glands on vitamin- 

 free casein food, the degree of development is enhanced if 

 vitamins are added. Back's latest investigations contribute 

 greatly towards a solution of this question. According to her, 

 large doses of vitamins added to the casein food have the 

 effect of shortening the lifespan. A very slight prolongation 

 was observed when very weak mixtures of vitamins were 

 added (mixture: Bj, Bg, Bg, A, C, E, K, nicotinic, pantothenic 

 and folic acids, biotin and inosite). Young bees fed with 

 vitamin-free casein food reared one generation of normal 

 brood; bad rearing occurred only with the second generation 

 of larvae. Young bees reared by nurses fed on a vitamin-free 

 diet are unable to utilize the protein in their food and thus 



