PROC. ENT. SOC. 'WASH., VOL. 23, NO. 5, MAV, 1921 107 



coating process enables the observer to follow the movements of 

 the larva as it proceeds with its work. In one instance when the 

 larva had completed its cocoon I made a hole in it by removing a 

 small part of the wall. I then placed the cocoon in the breeding 

 vial with the hole in contact with the sand but the larva failed 

 to repair the damage done and died after a few days. When 

 first finished the cocoon is the same color as the sand composing 

 it but later changes to a light chocolate color. 



While feeding the larva passes no faeces. All faecal matter 

 is retained in the posterior part of the alimentary canal until the 

 cocoon is completely formed. It is then discharged in the pos- 

 terior part of the cocoon to which it adheres in a dark, choco- 

 late-colored, sticky mass. No part of this faecal matter is used 

 in the construction of the wall of the cocoon. 



The number of brood chambers a single wasp will provide was 

 not learned since all the nests that were opened were incomplete. 

 The largest number found was eight and of these, four contained 

 only larvae of parasitic flies. In one brood chamber I found 

 twelve mature fly larvae. In what way the fly introduces her 

 eggs (or larvae) into the brood chamber of the wasp was not 

 learned. The first act of these fly larvae, doubtless, is to devour 

 the egg of the wasp. They then devour the grasshoppers. In 

 every brood chamber in which I found one or more fly larvae, 

 no egg or larva of the wasp could be found. 



On December 24, 1920, I opened two more nests of T. brevi- 

 ventris. I found a number of cocoons of which four were 

 removed without any damage, the others being crushed or 

 cracked in digging. In every case these cocoons were empty. 

 The four showed that the wasp had broken out of the cocoon 

 and escaped in the usual way, for, as is the rule in such cases, 

 the anterior end of the cocoon was open and the cocoon was 

 packed full of sand, which had been forced back into it by the 

 wasp as she digged her way out of the ground. Where do these 

 wasps spend the winter, and how do they spend the time from 

 spring to September while waiting for the grasshoppers to grow 

 to a size that will make them suitable for food for the next 

 generation of wasps? 



FURTHER NOTES ON AMBOPOGON HYPERBOREUS GREENE. 



(DIPTERA.) 



By CHARLES T. GREENE, U. S. Bureau of Entomology. 



When I described this species 1 I had but one male specimen 

 and was unaware that it was not fully colored. At the present 

 time I have four additional males and a female. Since I have 



'A New Genus in Scatophagiciae (Diptera), C. T. Greene, Proc. F.nt. Soc- 

 \Vash., vol. 21, no. 6, June, 1919. 



