EFFECTS ON THE HIGHER INVERTEBRATES 65 



Hymenoptera.— Lucas (1826) cites Trembley ("Biologie") as authority 

 for the statement that "Die Insecten-geschichte gibt uns Beispiele von Bienen, 

 Ameisen, verschiedenen Raupenarten von Wurmern, Schmetterlingen und 

 Fliegen, welche ganze Monate ohne die geringste Nahrung hinbringen." This 

 probably refers to the period of dormancy or hibernation, however, as perhaps 

 likewise the period of one year noted by Reaumur for the wasp, Vespa vulgaris. 

 Lucas himself found the following periods required for death from starvation: 

 ant, Formica fusca, two days (in May); bee, Apis terrestris, three days; Apis 

 mellifica, four to six days or more (in June) ; Vespa vulgaris, eight days. Slowt- 

 zoff ('04a) observed that the bumble-bee, Bombus terrestris, dies after only 24-48 

 hours of absolute inanition, with loss of about 24 per cent in body weight. 

 The loss is chiefly in water content, which is considered the cause of death. 



The effect of the nutrition upon sex-development in ) the Hymenoptera 

 has attracted much attention. Von Siebold observed in the wasp, Nematus 

 ventricosus, a progressive increase in the percentage of females during the 

 spring and summer, probably due to the effects of increased warmth and 

 food. In the honey-bee {Apis mellifica), however, it is well known that sex is 

 determined by fertilization, the unfertilized eggs producing the males (drones). 

 If larvae from the fertilized eggs are well-fed with the "royal diet," they become 

 queens, with functional reproductive tract; but if fed with the less rich, ordinary 

 diet, they become workers, with rudimentary reproductive tract. According 

 to Von Planta the "royal diet" is relatively twice as rich in fats as 

 the ordinary diet, though slightly poorer in glucose and protein. The drones are 

 males resulting from unfertilized eggs and are not due to difference in the diet. 



Eimer ('88) concluded that " Geschlechter giebt es in der Hummelfamilie 

 nur zwei: Mannchen und Weibchen, denn die kleinen und grossen Arbeiter 

 sind nichts als in Folge von schlechteren Ernahrung, vor Allem der mangelnden 

 Honigfutterung wahrend des Larvenlebens, geschlechtlich unvollkommen 

 entwickelte Weibchen." Attempts to determine sex by nutrition of the honey- 

 bee larvae have been unsuccessful (Dalla Torre, '10). 



Popovici-Baznosanu ('10) observed that among the bees Osmia rufa and 

 Osmia cornuta a greater amount of food is deposited in the cells of the larvae 

 producing females than in those producing males. Experimental removal 

 of a portion of this food resulted in a marked reduction in the size of the adult 

 bees, both male and female. 



Among the ants (Formicidae), according to Emery ('94), the females, like 

 those of termites and bees, exhibit a remarkable "Nahrungspolymorphismus." 

 In this case, the quality of the food apparently determines whether the larva 

 shall become queen or worker. There are, moreover, two different kinds of 

 workers, small and large, probably determined by the quantity of food supplied. 

 In some species, there are intermediate stages between the large and small 

 workers. O. Hertwig ('20) adopts Spencer's theory that these intermediate 

 forms may depend upon the developmental stage at which the larvae are sub- 

 jected to inanition. Apparently no experimental evidence upon this question 

 is available. 



