packaijd] the social life of ensects. 



345 



The leaf cutter or tailor bee is also partly social, in so far 

 that it makes a munber of cells and places them close 

 together in the hollow of the branch or stalk of some pithy 

 plant, such as the elder, but like the Andrena and mason 

 bee there is no combination of two or more indiviiluals as in 

 the trul}' social wasps and bees. The leaf-cutter bee some- 

 times builds as many as thirty cells, arranged end to end. 

 Usually, however, but a few cells are made. Fig. 257 repre- 

 sents three such cells in the stem of an elder stalk. 



I am not aware that there is any other bee which at all 



Fig. 256. 



Cells of Mason Bee iu a srall. 



approaches the tailor bee in the unique habit of cutting out 

 circles from rose leaves and so adjusting them as to form a 

 cartridge like cylinder. Fig. 258 represents the bee in the 

 act of cutting out these circles. The act is as deliberate and 

 methodical as that of the Attelabus, the weevil which so caie- 

 fully cuts and rolls up the leaf into a solid carliidge-like 

 mass in which to deposit its eggs. It also invariably, so far 

 as I am aware, selects the rose. A single bee in one in- 

 stance, as observed by Mr. F. W. Putnam, cut out at least 



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