TWO POTTER WASPS 385 



It grows rapidly, doubling in size in three days, and in 

 one week it is five times its original length and full grown. 

 Twenty-two caterpillars in one week is not a bad feast for 

 so small a creature, yet the bulk of the eater and the eaten is 

 approximately the same. 



Upon finishing the last caterpillar the grub rests for 

 twenty-four hours before coating the interior of its cell and 

 spinning its cocoon, a process quite similar to that employed 

 by the other potter of this chapter. Transformation follows 

 a week after spinning, bringing to light a yellow pupa not 

 as oddly shaped as that of the red Eumenes. 



Its thorax, waist and abdomen are a closer approach 

 to a straight line. It therefore requires proportionally less 

 room and its cell is flattened and otherwise constructed 

 accordingly. 



Here as with the red species, I must drop the wasp 

 at pupation. With all my care and repeated trials I was un- 

 successful in rearing the species to maturity. I found it sim- 

 ple enough to hatch the eggs, rear the grub and observe 

 pupation, but beyond that point I remain in darkness. On 

 the eve of emergence, my priceless pupae shrivelled and died, 

 and who can say why? 



