140 SAWFLIES AND BEES 



hairs are shorter and more even, and there 

 is no black on the abdomen. Bombus 

 smithlanus (Plate XIII., Fig. 9), sixteen 

 lines, is met in Orkney, Shetland, and the 

 Hebrides. The thorax is bright fulvous, 

 and the abdomen lemon-yellow. The male 

 merely has a brighter shade of yellow in 

 the abdomen. 



The next bee, Psithyrus rupestris (Plate 

 XIII., Fig. 10), eighteen lines, is a member 

 of a genus which makes no nest, but 

 shares the nests of other bees. Rupestris 

 is a guest of the red-end bee lapidarius. 

 It is not known what benefit, if any, these 

 lodger bees confer on their hosts, but we 

 may assume that they are 'paying guests.' 

 The bee is black, with its abdomen orange- 

 red. Another genus of bees, named Megachile, 

 is remarkable for lining its nest with sections 

 neatly cut from the leaves of roses and other 

 bushes. Having selected a hole in a decay- 

 ing post or tree, a bank, or an old wall, 

 the female bee, with marvellous skill, bites 

 out of the leaves portions of varying size 

 and shape, exactly calculated to form the 

 cells which she desires to construct, Her 



