1S95.I 257 



It seema pretty clear that the Sphecodes must have been either 

 (1) an inquiline of Eucera, or (2) an inquiline of Andrena nigrocenea 

 or lahialis, or else (3) that it was not an inquiline at all. 



Noticing the Sphecodes males amongst such a number of those of 

 Eucera, I at first thought that the first alternative was the correct 

 one. Upon a little consideration, however, it seemed very improbable 

 that it was so, for though the males of the two bees flew together, the 

 females of the Sphecodes were disappearing as the Eucera females 

 were emerging from the bank. In order for the Sphecodes to lay her 

 eggs in the cells of Eucera, it would have been necessary for the 

 former to be about when the latter was laying up her store of pollen ; 

 this was not the case. 



"With regard to the third idea, I did not see a Sphecodes female 

 excavating, nor did I see one laden with pollen ; the whole physique 

 of the bee is against the idea, as also are the movements of the female, 

 referred to above. 



It must then have been an inquiline of one of the Andrence. The 

 time of the appearance of the females would confirm this theory, for 

 A nigrocenea was completing her store of pollen when the Sphecodes 

 females were seen. 



In order to further investigate the matter, I made a thorough 

 search in the bank on August 24th, unearthing the following: — 

 12fi Eucera cticoons containing lavvso. 

 54 Eucera cocoons containing fully developed bees of both sexes. 

 49 remains of dead Eucera bees in cocoons perforated with holes. 

 12 pellets of decayed pollen in Eucera cells. 

 270 old Eucera cocoons filled with earth. 



1 larva from Eucera cell (which afterwards span). 

 75 fully developed A. nigrocBnea bees of both sexes. 

 9 pupae of A. nigrocBiiea rapidly turning into bees. 

 6 fully developed A. lablalis bcos (including one male). 

 5 males and 2 females of !S. ruhicundus (fully developed). 

 As the Sphecodes are of special interest, 1 will give the account 

 of each one from my notes. 



No. 1, (J ; fell out of excavation just before I came on a group of A. nigrocenea, 



and just before I had unearthed a lahialis. 

 No. 2, S ; length, 6 mm. ; uneonsumed pollen left in cell ; fell out from burrow 



a little before I came on a group of A. nigrortttea. 

 Nos. 3 and 4, S : fell out as I was excavating the above group. 

 No. 5, ? ; found in cell in above excavation. 

 No. 6, <? ; length, 11 mm. ; fell out of cell just after I had taken a specimen of 



A. lahialis; a large bee. 

 No. 7, ? ; found in cell amongst group of A. nigrocenea. 



