LIFE-HISTORIES OF SOLITARY WASPS 271 



less mysterious if we open the nest at an earlier period, 

 for then one or more white grubs will be found 

 devouring the fresh food by which they are sur- 

 rounded. The supply is, however, usually sufficient 

 to enable the young to attain their full growth, and 

 to pupate successfully. Careful examination of the 

 earliest stage will reveal one or more eggs prone or 

 pendent, which are laid by the wasp among the store 

 of moribund caterpillars in the still earlier formed 

 clay nest. 



There is no 'doubt that the wasp makes the clay 

 with its saliva, builds the nest, stores it with a par- 

 ticular insect, and then, after laying an egg or two, 

 leaves the warmth of the situation to complete the 

 development of its young. The entire work falls upon 

 the female. 



Sand Wasps. These solitary wasps are of diverse 

 kinds, and many dig burrows in the ground, construct 

 cells of pottery, or tunnel into wood. In all cases it 

 is the female wasp exclusively that does the work. 

 The males usually live for a short time, and take no 

 part in the construction of the nest or the care of the 

 young. Ammophila of sandy districts is well known 

 (Peckham, Fabre, p. 300). 



For digging its burrow this wasp uses mainly the 

 same instrument that others employ to collect earth 

 for pottery work namely, its strong jaws, aided 

 by the first pair of legs. Having selected a spot on 

 suitable ground, and on a hot day, the red-banded black 

 Ammophila picks away the earth until she is partly 



