OTHER MEMBERS OF THE (T.AS,^ — INSECTA 193 



isituations, usually in holes which they excavate in soft 

 wood or which they find already made. 



The social bees — honeybees and bumblebees — are of 

 considerable economic value to man. The honeybee 

 furnishes us with two most valuable products, honey and 

 wa.x, while the 

 bumblebee cross-fer- 

 tilizes our fields of 

 clover. Yet it is not 

 of the social bees 

 that we shall speak, 

 but rather of the 

 solitary ones with 

 which we are not so 

 familiar. Perhaps 

 the small carpenter 

 bee, the large car- 

 penter bee, and the leaf-cutter bees are the most common 

 of the solitary bees. The female of the smaU carpenter bee 

 is about a quarter of an inch long. She selects a twig 

 hiost often of the sumach, that has a soft pith and excavates 

 in it a long tunnel. At the bottom she puts in a supply of 

 pollen, lays an egg, and then builds a partition above it, 

 lays another egg on pollen, builds another partition, and 

 so on, until only room is left for her to rest at the mouth 

 of the tunnel, to watch and wait until the young bees appear. 



There is a large carpenter bee that bores into solid wood 

 and builds a nest there much like that of the smaller one. 



The leaves of rose bushes are often found with oblong 

 and circular notches neatly cut along the edges. This is 

 the work of a small leaf-cutter bee (Fig. 140). This bee 

 first builds a tunnel in partly decayed wood, then cuts 



Fu:. 130. — Xe.st of mud-dauber : the uncapped 

 cells show that the young wasps have become 

 mature and flown away. 



HERRITK S 



ZOOL. — 13 



