152 NOTES ON ANTHOPHORA ABRUPTA 



the stored cells before they are closed, and the rapidly developing 

 fly larvae cause the female bees to abandon them before they have 

 finished with their provisioning. I have never found the 

 puparia in a properly sealed cell, but several times have found 

 partially opened cells which contained a large number of them. 

 Usually ten or twelve puparia occurred near one another in the 

 infested burrows. As adults of Pegomyia affinis were ol^served 

 flying about the holes in the bank on September 20, it is prob- 

 able this fly has more than one generation a year. 



A true parasite of Anthophora abrupta is found in the bomby- 

 liid fly Spogostylum albofasciaium ]\Iacquart (det. J. B. Mal- 

 loch). I first found the larva of this parasitic fly on May 31, 

 1919, in a bee cell. This larva transformed to a pupa on July 

 5 and emerged as an adult on July 26. On December 30, 1919, 

 and April 9, 1920, I found two other larvae of this species in 

 cells of Anthophora abrupta. Various other investigators have 

 found Spogostylum albofasciatiim to be a parasitic species. 

 There is also a probability that the larva of this bombyliid, 

 after having destroyed the bee egg or killed the larva, will feed 

 on the pollen stored in the cell. I am certain, however, that 

 no bees develop from cells that produce these flies, and therefore 

 Anthophora must fall a victim to the fly larvae in either the egg 

 or larval stages, sometime before the advent of fall and winter 

 conditions. Malloch (1917) describes and figures the pupa of 

 this species and gives a good general account of the inquilinous, 

 predaceous and parasitic habits of this family. 



Probably the worst fly parasite of this bee is a conopid. Un- 

 fortunately I have never been able to rear the adult. The 

 puparium is quite similar to that of Physoccphala sagittaria 

 Say, a parasite of the bumblebees. I first found this parasite 

 in dead and nearly dead bees which had fallen to the ground 

 at the base of the bee bank at Oakwood on July 3, 1919. Dis- 

 section of these bees revealed the presence of the characteristic 

 conopid larvae and in one specimen a recently formed puparium. 

 In 1919 I tried to rear the adults of this fly ])ut failed, due in 

 sotne cases perhaps to poor conditions of humidity, but in five 

 instances to the effectiveness of a secondary Hymenopterous 

 parasite. Mr. A. B. Gahan very kindly named this secondary 

 parasite for me as Mestocharis williamsoni Girault. It is inter- 

 esting to note that this is the same species of Mestocharis that 



