WASPS, SOCIAL AND SOLITARY 



entrance to the nest ; but the precaution seems still less 

 necessary even absurd in the Bembex field, where 

 there is no possibility of concealing the colony, and 

 where the nests are only an inch or two apart, so that 

 an enemy might burrow anywhere with the certainty of 

 finding one. Moreover, the only enemy that we could 

 discover was the parasitic fly, which never attempts to 

 enter when the hole is closed. However, unmoved by 

 our opinion on the subject, spinolae spends five or six 

 minutes of her precious time in making the neighbor- 

 hood of her home quite tidy, and then she fills in the 

 mouth of the nest with a little loose earth before going 

 away to catch her fly. 



Oxybelus, though she is limited in choice by her small 

 size, can catch a fly in three or four minutes. Bembex 

 is strong enough to take anything that she sees, and she 

 has no preference for one species above another, yet she 

 seldom finds one under twenty or twenty-five minutes. 

 When she comes back nothing of the fly is visible unless 

 it is unusually large, so closely is it held under her body 

 by the second pair of legs. She alights, and scratches 

 away the loose earth at the entrance of the nest with her 

 first legs, and then, as she creeps within, she passes the 

 fly along from the second to the third pair, so that the 

 end of its body, projecting beyond the abdomen of the 

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