A Parasite of the Bembex 289 



omitted by accident or design, next day or the 

 day after I was sure to find the Fly's grubs 

 greedily slicing up the larva of the Bembex. 

 So, when the nest is invaded by the parasites, 

 the lawful larva is doomed to perish, either 

 by hunger or by a violent death ; and this is 

 what makes the Bembex hate the sight of the 

 Miltogrammae prowling around her home. 



The Bembex are not the only victims of these 

 parasites : all the Digger-wasps without dis- 

 tinction have their burrows plundered by 

 Tachinae and especially Miltogrammae. Differ- 

 ent observers, notably Lepeletier de Saint- 

 Fargeau, have spoken of the wiles of these bold- 

 faced Flies ; but none of them, so far as I know, 

 has remarked this very curious instance of 

 parasitism at the expense of the Bembex. I 

 say very curious, because the conditions are 

 quite different. The nests of the other Digger- 

 wasps are stocked beforehand and the Milto- 

 gramma drops her eggs on the pieces of game 

 as they are taken in. When the Wasp has 

 finished her catering and laid her ^^'g, she 

 closes the cell, where henceforth the lawful 

 larva and the alien larvae hatch and live to- 

 gether without ever being visited in their 

 solitude. The mother therefore is not aware 

 of the parasites' brigandage, which remains 

 unpunished because it is unknown. 



