HYMENOPTERA 997 



The water-proofing of the wall of the cell is an essential feature 

 for without it the semi-fluid mass of pollen and nectar with which 

 the cell is provisioned would be partially absorbed by the wall of 

 the cell. 



Fig. 1222. — Section of a bank with nests of Anthophora, (Photographed by 

 Miss P. B. Fletcher.) 



The larvas remain in their cells throughout the winter, and trans- 

 form to pups in the spring. The duration of the pupa state is short, 

 the adult bees appearing early in the summer. The parasitic beetles 

 Hornia are often found in the nests of Anthophora. 



Andrena. — Among the larger of our common mining bees are 

 certain species of the genus Andrena; some of these nearly or quite 

 equal in size the workers of the honey-bee. They build their nests in 

 road sides and in fields that support a scanty vegetation. They sink 

 a vertical shaft with broad cells branching from it. These bees, 

 though strictly solitary, each female building her own nest, frequently 

 build their nests near together, forming large villages. I once re- 

 ceived from a correspondent a description of a collection of nests of 

 this kind which was fifteen feet in diameter, and in the destruction of 

 which about two thousand bees were killed ; what a terrible slaughter 

 of innocent creatures ! 



The small carpenter-bee, Cerdtina dupla. — The nests of this bee 

 are built in dead twigs or sumac and in the hollows of brambles and 

 other plants. They are more common than those of any other of our 

 solitary bees that build in these situations. This is a dainty little bee. 



