WASPS AND BEES. 



131 



in gravelly walks, and have the instinct to sting grass- 

 hoj^pers in one of the thoracic nerve-centres, thus paralyzing 

 the victim, in which the wasp 

 lays her eggs; the young hatch- 

 ing, feed upon tlie living but 

 paralyzed grasshoppers, the 

 store of living food not being 

 exhausted until the larval wasp 

 is ready to stop eating and 

 finish its transformations. 



The genuine paper-making 

 wasps are numerous in species; 

 here the workers are winged, 

 and differ from the females or 

 queens in being rather smaller. 

 Odynerus builds cells of mud. 

 Tlie genuine paper-making 

 wasps, such as Vespa, build 

 several tiers of cells, arranged 

 mouth downward, and envel- 

 oped by a wall of several thick- 

 nesses of paper. In the Vespce, 

 the females found the colony, 

 and raise a brood of workers, 

 which early in the summer 

 assist the queen in completing 

 the nest. 



The bees also present a grad- 

 ual series from those which 

 are solitary, living in holes in 

 the eartli, like the ants (Fig. 

 173), and forming silk-lined 



earthen cocoons, to those Fiq l 3 —Nest o( Andrena q level 



, . , . , .,, . , jf ground, a, fiihtniade cell, con 



which are social, with winged taming a pupa; 6, Z, larvee; e,pol- 



1 T 1 1 T i* ■ J? len mass with an egg laid on it; /, 



workers, slightly dinering from pdlen mass freshly deposited by 



the queens. The queen hum- 

 ble-bee hibernates, and in the spring founds her colony by 



