HYMENOPTERA 229 



Family Apidse (bees). Clothed with feather-like hairs, 

 the first joint of the hind foot (tarsus) is lengthened and 

 sometimes expanded in width also. No wingless forms occur. 

 Social (with workers) or solitary. 



The hive-bee is described in Lesson 19. 



Family Fossores (digging-wasps). In this family the wings 

 are not folded, the segments of the waist are not unequally 

 thickened, and there are only two kinds of individuals (males 

 and females) in each species. 



Family Diploptera (true-wasps). The fore wings are folded 

 lengthwise when at rest. Some wasps are solitary, others 

 social, living in communities of males, females, and workers. 



Family Formicidse (ants). The antennae are elbowed. 

 The first abdominal segment is joined to the thorax; the 

 second is small, mobile, and thickened in the middle; the third 

 may also be narrowed in one sub-family, the workers of which 

 sting. Ants live in communities of males, females, and workers, 

 the workers being always wingless. The larvae are footless 

 grubs reared by the workers. 



No solitary ants are known ; they live in communities, which 

 are in many respects the most completely organised known 

 among animals. Though the society provides for its various 

 needs by division of labour, sometimes carried to an extra- 

 ordinary point, and by the industry and devotion of its 

 members, the intelligence of the individuals is not remarkable. 

 With very few exceptions the society consists of at least three 

 kinds of individuals, males, females, and workers (imperfect 

 females).* The males and females are winged, the workers 

 wingless. As among bees and wasps, the workers are in- 

 complete females, which have not altogether lost the power of 

 laying eggs, but cannot be fertilised, and therefore produce 

 only males. In summer the development of a new generation, 

 from egg to imago, only occupies a few weeks, but in winter 

 the larvae remain long unchanged, and do not undergo their 

 final transformation till the ensuing warm season. Ant-larvae 

 are footless grubs ; the pupae, popularly called "ant-eggs," are 

 either naked or enclosed in cocoons. The winged flies, which 

 are always male or female, are reared in the ant-hill, escape in 

 swarms on hot summer days, and mate in the open air. The 

 males then perish ; the females cast or bite off their wings, and 

 * The slave-making Anergates is believed to have no workers. 



