272 CLARENCE P. CUSTER AND CHARLES H. HICKS. 



The picture shows bee H in one of her numerous visits to the 

 plugged hole 7. Her action suggests that a bee retains the 

 memory of her nest for at least a week after it has been com- 

 pletely plugged up and that her visits are made to it to insure its 

 security from enemies. A brief extraction from my field notes 

 illustrates her action: "Bee H goes into nest 6 for one and 

 one half minutes, comes out and goes over to plugged hole 7. 

 She spends about ten seconds here. Upon arriving at 7, she 

 first puts her head down against the plug, rubs it with face and 

 mandibles and scratches weakly with fore legs for three or four 

 seconds. She then stands erect before the nest on her hind 

 legs with her fore legs against the bank above the plugged hole 

 (see picture). After standing thus motionless for about five 

 seconds, she flies away to the fields. She repeats this procedure 

 many times daily in like manner. Only occasionally does she 

 first go to nest 7 and then to 6" (c). 



While bringing out soil from within the nest, after the tunnel 

 has been constructed, bee D has been observed to back out, 

 raking it with her forelegs. She usually leaves this within an 

 inch of the entrance although in a few instances she took it 

 out in this manner as far as six inches, and once ten inches (c). 



D. sayi obtains the resin used in the construction of the nest 

 from the small sunflower, Helianthus petiolaris. She obtains this 

 resin, with her mandibles, from the stem and partially or totally 

 dried leaves which have small droplets and plates of it distributed 

 over them (c). 



Fabre (2) studied "resin workers" for many years but states 

 that he never saw a bee get resin. Friese (3) states, in reference 

 to the source of resin used by a species found in Europe, that it is 

 probably obtained from the buds of the pine. Hacker (4) 

 inferred that Megachile rhodura used resin for its nest since he 

 observed members of both sexes visiting a Eucalyptus tree, from 

 which resin had oozed, and rasping the resin with their mandi- 

 bles. However, he did not find M. rhodura nesting. Melander 

 (7) presumes that the resin used by Anthidium texanum Cres- 

 son was obtained from cedar. Hungerford and Williams (6) 

 say, in their account of Dianthidium concinnum (?) Cresson: 

 "The nest of this insect is composed of pebbles glued together 



