OF WASHINGTON, VOLUME XVII, 1915 73 



the sand at the bottom of the excavation made by the wasp 

 there was considerable excrement from the caterpillars but what 

 it was that proved so objectionable to the wasp I could not 

 determine. 



On July 29 No. 58 was discovered constructing her nest, to 

 complete which required a trifle more than ten minutes. In 

 this case I pulled the caterpillar out of the nest no less than 

 eight times. I hoped to induce the wasp to sting the caterpillar 

 as No. 55 had done but she made no attempt to do so. On 

 three occasions I pulled her out of the nest, clinging to the cater- 

 pillar with her mandibles, yet she never left the nest or made 

 any effort to carry off her caterpillar. This contention over the 

 caterpillar caused considerable sand to roll down into the nest 

 so that on three different occasions the wasp had to lay the 

 caterpillar aside and clean out the nest. A parasitic fly also 

 joined the controversy and in spite of my efforts succeeded in plac- 

 ing one or more larvae upon the caterpillar. None of these things 

 discouraged the wasp; she was determined to put her caterpillar 

 in that hole and I finally permitted her to do so. When the cater- 

 pillar was finally dragged within the nest the fly advanced to the 

 opening, backed around and deposited two or more larvae on the 

 edge of it whence they wriggled off and dropped to the bottom 

 of the nest. 



The wasp remained within the nest not quite two minutes. 

 After she had emerged and filled up the nest I captured her with 

 my net and digged up the nest. Although less than ten minutes 

 had elapsed from the deposition of the egg of the wasp to the 

 removal of the caterpillar from the brood chamber yet one of 

 the parasitic maggots was upon the egg, three more 1 were clus- 

 tered about it at the point of attachment to the caterpillar and 

 a fifth was tucked in between the fourth and fifth abdominal 

 segments on the ventral side. I removed these tiny larvae but 

 in doing so I must have injured the egg for it decomposed in the 

 breeding cell. 



No. 62 was discovered constructing a nest on August 1 and 

 I used the same tactics with this wasp as with the preceding. 

 Although I repeatedly pulled the caterpillar out of the nest and 

 also pulled the wasp out too on several occasions she made no 

 attempt to sting the caterpillar or to carry it away. On August 

 8 I discovered No. 64 filling up the nit mure to a nest in which 

 she had just placed a caterpillar. When this task was completed 

 she began immediately to construct n new nest a few inches from 

 the one just sealed up. When the nest was about one inch deep 

 I approached quite close to the nest and the wasp became fright- 

 ened and flew away, which fact leads me to believe that in this 

 case the wasp had no caterpillar in readiness to place within this 



