THE BEMBICENE WASPS 27 



to go past the loose dirt which has rolled down the sloping 

 channel from the temporary closing, and pause to kick this 

 dirt up in a heap (from within) which almost or entirely 

 closes the hole just beneath the level of the ground. They 

 gauge the strength of the kick with such remarkable ac- 

 curacy as to throw the dirt to exactly the right point near 

 the top of the burrow, but never out on top of the ground. 

 They usually leave a tiny crevice at the upper side of the 

 hole. This done, they later come squeezing and scrambling 

 out through the loose dirt. Even as they draw their bodies 

 out of the soft earth, they scratch the dirt back to close the 

 hole completely but loosely. They do not leave it open an 

 instant, or in any way give the parasites the least chance of 

 slipping by them. This loose mound is so near to the top 

 of the hole that a few more strokes usually suffice to finish 

 filling it. We have seen the opening smoothly cov- 

 ered with only five strokes. In making these temporary 

 closures, they give little or no attention to packing or 

 smoothing the surface of the ground over the closed nest. 

 Sometimes a wasp will pause a moment to sweep back the 

 surplus loose dirt from around, the top of the burrow to a 

 distance of six inches or more before flying away. 



The Peckhams, who quote Bates on Bembix ciliata, say 

 that this wasp sometimes leaves her door open when off on 

 a fly hunt ; she probably does this to save time. B. nubili- 

 pennis invariably closes her hole on leaving, but we fear 

 she does not burden her soul with anxiety for the value of 

 time, for we have often seen her scrape and scratch at the 

 hard-baked soil about her nest until we thought she would 

 wear her finger-nails off, working for more than an hour 

 to raise a little dust from the hard-packed earth to fill in 

 her burrow. 



Thus the temporary closures of the burrows are made 

 when the wasps are coming and going each day, bringing 



