142 NOTES ON ANTHOPHORA ABRUPTA 



with those of many of our common sohtary bees. Ashmead 

 has seen the same species of bee entering its burrow beneath a 

 stone in an open field. 



C. Hibernation 



Like many other Hymenoptera this bee hibernates as a larva 

 within its cell. I have never examined an Anthophora bank 

 during the winter months, but have other evidence in support 

 of this statement. A visit to Oakwood on September 20, 1919, 

 revealed the fact that the cells then contained full grown larvae. 

 At this time I again brought back to the laboratory a lump of 

 clay containing Anthophora cells. I divided this in halves, 

 placing one portion in an old deserted bee-hive outdoors, thus 

 subjecting the cell inmates to almost natural winter conditions. 

 The other portion I kept in the laboratory under temperature 

 conditions averaging about seventy degrees Fahrenheit. In 

 March, 1920, I examined these two separate lots of Anthophora 

 cells. On this date the inmates of the cells kept outdoors 

 under approximately natural winter conditions were still in the 

 larval stage. Those kept in the laboratory were still in the 

 larval stage in February, but the influence of warmer conditions 

 caused the larvae to begin to pupate in March. Thus we see 

 that this bee normally hibernates in the larval stage protected 

 by its earthen cell. 



D. Cell Formation 



The adult bees use some liquid substance when first fashion- 

 ing the cell, and it is probable that the larvae when they attain 

 their full growth also contribute something to give the cell its 

 characteristic dural)ility. When a clod of clay containing these 

 cells is broken apart, under ordinary conditions of stress the 

 cells never collapse but hold their shape and may be readily 

 sorted out from the debris. This again is pi'oof that the liees 

 and perhaps the larvae use a cementing substance. When a 

 cell is broken open its inner lining has a smooth glazed appear- 

 ance. This is due to the su])stance used in forming the pro- 

 tective cell and causing it to retain its charactei-islic shape. 

 A complete cell is usually slightly recurved at its anterioi' end, 

 which is an indication that the cells radiate off from the main 

 stem-burrow which leads to the entrance of the nest. The 



