764 



CLASS IV. INSECTA. 



cells of Osmia or to the same end breaks open the cells of Chalicodoma, 

 Nomada preys on Andrena and so on. 



Sub-f am. 5. Scopulipedinae. Solitary, not parasitic bees, with long 



ligula. A rather unnatural 

 group with four British genera 

 Anthophora, Ceratina, Eucera 

 and Saropoda. The first-named 

 resembles Bombus ; it often 

 makes cavities in cliffs. Xylo- 

 copa is a carpenter bee and 

 makes its cells in dry timber. 

 Euglossa, a very fine form, 

 has a proboscis much longer 

 than its body. 



Sub-fam. 6. Dasygastrinae. 

 The ventral surface of the ab- 

 domen bears densely set hairs 

 for entangling the pollen ; 

 labrum often long and with the 

 mandibles locking outside when 

 it is depressed. The Mason- 

 bees build cells of cement 

 secretion (salivary gland, mixed 

 with sand, earth and stones). 

 In these they store honey and 

 pollen. Chalicodoma builds 

 several cells one after the 

 other, and when some eight or 

 nine are complete it covers the 



whole with a dome-shaped covering. Anthidium makes cells of 



down and cotton collected from plants, and places them in such 



shelters as empty snail-shells or the cells of other Hymenoptera. Osmia 



also selects already formed shelters in timber, walls or banks. 



Megachile is the leaf cutting bee, and makes a series of cells in some 



small burrow out of pieces 



of plant-leaves which it 



neatly cuts and places. 



There are four British 



genera. 



Sub-fam. 7. Socialinae. 



Social bees, which form 



\ 



FIG. 496. Chalicodoma muraria. Greece. 

 A male ; B female. From Sharp. 



colonies, with different 

 grades of females. In 

 Bombus the workers are not 

 externally clearly differen- 

 tiated from the queens, and 

 in the autumn each com- 

 munity perishes, save for a 

 few females which survive the 

 winter, and each of which acts as a queen and starts a new colony in the 

 spring. The waxy cells are piled together irregularly in some hollow in 

 the ground or in a bank, and a well-filled community contains only some 

 few hundred bees, in some species even fewer. The wax is secreted 



FIG. 497. Osmia tricornis ? . Algeria. 

 From Sharp. 



