NESTING HABITS OF SOME ANTHIDIINE BEES. 263 



jnto a cell shaped for the reception of the pollen. She usually 

 turned herself around once and sometimes two or even three 

 times in the placing and working of each load. 



In returning to the nest the bee came direct, leaving in the 

 same manner. Although the weather was partially cloudy the 

 bee carried 26 loads of down in two days, an average of six 

 minutes and thirty-eight seconds for each load. 



The time of individual trips varied from 4' 49" to 16' 05". 

 The time spent within the nest, arranging the down varied from 

 i' 10" to 2' 20". The time taken to get the down is determined 

 by weather conditions, distance secured from nest, time of day, 

 etc. 



At the time of provisioning, the cell had an inner cavity, a 

 little larger than the bee. She began at i : 40 to carry pollen and 

 between this time and 3 : 30 carried 6 loads. The time spent 

 within the nest averaged about 2 minutes. On arriving, the bee 

 opened the top of the cell, entered head first, came out, and 

 backed in, forcing the abdomen inside. While here, she removed 

 pollen from the ventral scopa and deposited it in the bottom of 

 the cell. Before leaving the nest, she always partially closed the 

 cell by raking the down together at the orifice. This may make 

 it more difficult for parasites to find or enter the nest. 



After depositing the pollen, the bee was not seen to enter the 

 cell again until she had returned from another collecting trip. If 

 nectar was deposited after each collecting trip, it of necessity was 

 deposited first when the bee had her head within. However, the 

 first pollen was seen to be dry and it was not learned if separate 

 trips were made to gather nectar or not. The final food for the 

 young is very moist (h). 



After provisioning, laying the egg and closing the cell the bee 

 fills up the tunnel, usually with pebbles. These may be selected 

 from a small area over 9 yards from the nest, in rare instances, 

 but more usually from i to 3 yards away. A number of times 

 the bee has availed herself of the pebbles of a large red ant nest 

 (Pogonomyrmex occidentalis Cresson). 1 The number of pebbles 

 used is at least enough to fill the tunnel above the cell even 

 with the surface of the ground. The size of the tunnel and the 



1 Kindly determined by Professor T. D. A. Cockerell. 



