SPHEGIDAE 295 



the species was not identified, since this method of nesting 

 is very unusual for a fossor. 



Another very unusual nesting place was found to be 

 used by a specimen of Sphex (Isodonta) pelopaeiformis. 

 This was in the open end of the hollow stem of a broken 

 reed. The Sphex was seen going there carrying a small 

 piece of wood, and I found she had finished provisioning 

 her nest and was stopping the hole at the end of the stem. 

 There were two collections of stored up Locustidae, belong- 

 ing to species of very different types ; all were young, 

 and in some the wings had not begun to grow. There 

 were nine in one chamber and six in the other, the two 

 being separated by a partition partly of earth, partly 

 of some soft brown substance of almost woolly texture 

 whose origin was unknown. One Locustid of each col- 

 lection had the Sphex's egg affixed to it on the under 

 surface close behind the head. It is very interesting that 

 this fossor, while abjuring the earth as a nesting place, 

 still made use of it as material wherewith to form a 

 partition between the two collections of prey. 



Another Sphegid with nesting habits unusual among 

 this group is the extremely common and widespread 

 Sceliphron spirifex, familiar in every house ; it is even 

 found in South Europe. 



This rather elegant black and canary-yellow species, 

 with long limbs and narrow pedicle to the abdomen, is 

 classed as a " Mud wasp " by the annoyed housewife, 

 from its habit of building a collection of earthen cells 

 in any convenient nook, such as the fold of a curtain, 

 the corners of open boxes, the back of a book, and such- 

 like places. Like most Sphegidae, this energetic worker 

 emits a curious note when working — a quavering, high- 

 pitched buzz rising and falling slightly that is presumably 

 made by quick vibrations of the wings as they lie upon 

 the back. There are few houses in which this sound 

 cannot be heard coming from some obscure corner. The 



