HYMENOPTERA. 135 



attaches to the stems of plants such as heath. After 

 filling the nest with young caterpillars the female lays 

 an egg therein and closes the mouth of the nest. When 

 the young larva is hatched it feeds on the contents, and 

 when ready to emerge it eats its way out of the nest 

 through the side. 



Other kinds, as in the insects of the genus Odynerus, 

 form burrows in sandbanks, in which they construct 

 their cells, which are often built of mud ; in these cells 

 young caterpillars are placed and the eggs then laid. 



The I'amily of Vespidw contains the . Social-wasps, 

 which are divided into Tree-wasps and Ground- 

 wasps ; these consist of males, females, and neuters. 

 The Tree-wasps attach their nests to the branches of 

 trees and woodwork of outhouses ; but their habits are 

 not invariable, for the Ground-wasps sometimes suspend 

 their nest in the roofs of houses. 



There are seven British species of Wasp, of which 

 the Hornet ( Vespa crabo) is the largest and most for- 

 midable. The societies of Wasps are annual ; all die 

 excepting the females, which are all able to survive the 

 cold of winter, and ready at the return of spring to 

 become the parents of thousands. In Plate V., Fig. 1, 

 is the Hornet ; Fig. 2, the Common Wasp ; and Fig. 3, 

 one of the Tree-wasps ( V. sylvestris). 



The sub-section, Anthophila (flower-lovers), contains 

 the Short-tongued Bees and the Long-tongued Bees ; 

 the former, consisting of the family of Andrenidse, are 

 solitary ; only perfect sexes are known in the two 

 genera of this family. Colletes burrows in sandbanks 

 and sandstone, and plasters the inside of the burrow — 

 which is a tubular cell six to ten inches long — with a 



