NESTING HABITS OF SOME ANTHIDIINE BEES. 273 



with resinous cement which may be derived from the stems of 

 Helianthus which are often infested with a small lepidopterous 

 borer that causes an exudation which usually attracts a host of 

 Hymenoptera." 



The following field notes were taken, giving the resin activities 

 of bee C during one hour: 



12:57^. Arrives with resin in mandibles at nest 2. Kneads 

 resin with mandibles. 



i : oo. Obtains a piece of chaff an inch away from nest and 

 inserts it into the resin which by now she has shaped into a plug 

 over the ends of the pieces of chaff projecting from the burrow. 



i : o6f . Carries piece of chaff to nest 2. 



i :O7. Obtains small stick and flies with it to nest i. 



1:07^. Flies away. I follow her. She goes to some flowers 

 of Grindelia and feeds. 



1:09^. Flies to some dried plants of Helianthus petiolaris. 

 Picks a plant without many red and black ants present and 

 scrapes resin off with mandibles. She visits three plants. 



i : I2f . Arrives from fields at nest 2. Has in her mandibles a 

 load of resin about one fourth as large as head. Distributes 

 resin over ends of chaff projecting from the entrance. 



1:21. Flies to nest i . 



1:21^. Leaves nest i. Goes directly to sunflower plants and 

 secures resin. 



i : 24. Arrives at nest 2. 



i : 25^. Leaves nest 2. 



i : 30. Arrives and leaves after two seconds. I follow her to 

 several flowers of Grindelia where she feeds. 



1:32. Arrives at nest 2 and leaves, after two seconds, for 

 the fields. 



i : 34^. Arrives at nest i with white resin in mandibles. 

 Works here with the resin in the construction of a plug. 



1:36!. Obtains large pebble two inches away and inserts it 

 into resin of nest i. 



i : 38. Flies to nest 2 and works with plug there. 



i : 42. Carries stick to plug at nest 2. 



\:\2\. Leaves nest 2 and feeds at flowers of Grindelia and 

 of Plelianthus petiolaris. 



