122 HYMENOPTERA CHAP. 



supplies. In doing so she is fulfilling her duty ; what matters 

 it that she is nourishing the enemies of her race ? Both race 

 and enemies have existed for long, perhaps for untold periods of 

 time, why then should she disturb herself, or deviate from her 

 accustomed range of duties ? Some of us will see in such pro- 

 ceedings only gross stupidity, while others may look on them as 

 sublime toleration. 



The peculiar habits of Bembex rostrata are evidently closely 

 connected with the fact that it actually kills, instead of merely 

 paralysing, its prey ; hence the frequent visits of supply are neces- 

 sary that the larvae may have fresh, not putrefying, food; it may 

 also be because of this that the burrow is made in a place of loose 

 sand, so that rapid ingress may be possible to the Bembex itself, 

 while the contents of the burrow are at the same time protected 

 from the inroads of other creatures by the burrow being filled 

 up with the light sand. Fabre informs us that the Bembex 

 larva constructs a very remarkable cocoon in connection with 

 the peculiar nature of the soil. The unprotected creature has 

 to pass a long period in its cocoon, and the sandy, shifting soil 

 renders it necessary that the protecting case shall be solid and 

 capable of keeping its contents dry and sound. The larva,, how- 

 ever, appears to have but a scanty supply of silk available for 

 the purpose of constructing the cocoon, and therefore adopts the 

 device of selecting grains of sand, and using the silk as a sort of 

 cement to connect them together. For a full account of the 

 ingenious way in which this difficult task is accomplished the 

 reader should refer to the pages of Fabre himself. Bembe- 

 cides appear to be specially fond of members of the Tabanidae 

 (or Gad-fly family) as provender for their young. These flies 

 infest mammals for the purpose of feasting on the blood they 

 can draw by their bites, and the Bembecides do not hesitate to 

 capture them while engaged in gratifying their blood-thirsty pro- 

 pensities. In North America a large species of Bembecid some- 

 times accompanies horsemen, and catches the flies that come to 

 attack the horses ; and Bates relates that on the Amazons a 

 Bembecid as large as a hornet swooped down and captured one 

 of the large blood-sucking Motuca flies that had settled on his 

 neck. This naturalist has given an account of some of the 

 Bembecides of the Amazons Valley, showing that the habits there 

 are similar to those of their European congeners. 



