488 



HYMENOPTERA 



CHAP. 



man." ^ The mechanical perfection of the structures of the 

 individuals, and the rapid and efficient manner in which their 

 functions are discharged, are very remarkable. In many species 

 of Hymenoptera the individuals have the habit of living together 



in great societies, in 

 which the efforts of 

 the members are com- 

 bined for the support 

 of the whole society 

 and for the benefit 

 of a younger genera- 

 tion. To fit them 

 for this social life 

 the bodies of the 

 larger number of the 

 individuals are more 

 or less changed in 

 structure, so that 

 they become workers. 

 These workers are in 

 all cases imperfect 

 females ; besides 

 carrying on the 

 ordinary work of the 

 society, they tend and feed the young. The duty of reproduc- 

 tion is restricted to a single female, called a queen, or to a small 

 number of such individuals in each society. The males occupy 

 an unimportant position in the society, and are usually much 

 shorter-lived than the workers and queens. The social Hymen- 

 optera do not form a single zoological group, but are of three 

 different kinds wasps, bees, and ants. There are numerous 

 non-social, or solitary, wasps and bees. 



In the Order Hymenoptera especially in the higher forms 

 the males and females are often different in appearance and 

 structure. In the ants, one of the social groups, the workers, or 

 imperfect females, are quite wingless. There are numerous other 

 groups in which species, not social, are fovmd, having the females 

 wingless while the males have wings. In a few species there is 

 an apterous condition of the male, perhaps usually only as a 



^ P. ent. Soc. London, 1866, p. Ixv. 



Fig. 331. Bomhus Incorum. A, Adult larva ; B, pupa 

 C, imago, female. Britain. 



