228 



PSYCHE. 



[March 1S92. 



May 25, June 2, June 11, June 20. 



May 25, June 4, June 15. 



May 25, June 2, June 11, June 19. 



Four jars started May 27 have the 

 following record : 



May 27, June 6, June 15. 



May 27, June 11, June 15, June 20. 



May 27, June 6, June 15. 



May 27, June 6, June 15, June 21. 



Thirteen jars started June 2nd, each 

 jar being infected with four fungus- 

 covered bugs from the preceding jars, 

 are recorded as follows : 



June 2, June il, June 20. 



June 2, June 11, June 19. 



June 2, June 11, June 19. 



June 2, June 7, June 15. 



June 2, June 11, June 15, June 20. 



June 2, June 11, June 19. 



June 2, June 11, June 19. 



June 2, June 1 1, June 20. 



June 2, June 15. 



June 2, June 11, June 19. 



June 2, June n, June 19. 



June 2, June 11, June 15, June 20. 



June 2, June 11, June 15, June 20. 



One jar started June 4 ran : 



June 4, June n, June 20. 



One jar started June 5 ran : 



June 5, June 15, June 20. 



Four jars started June 6 are recorded : 



June 6, June 15, June 20. 



June 6, June 15, June 19. 



June 6, June 15. 



June 6, June 19. 



The bugs put into the jars on the sev- 

 eral dates were from all parts of the 

 chinch bug district of the State of Kan- 

 sas. They were for the most part just 

 received from the mail and were in vig- 



orous condition. They were kept sup- 

 plied with green wheat. While the bugs 

 in the infected jars were dying at inter- 

 vals of five to ten days, bugs from the 

 same lots in isolated check jars remained 

 alive and vigorous. 



By June 20th the demand for infected 

 bugs was so large that the jar method of 

 infection required more attention than 

 we were able to give it. The results of 

 our separate lots were so uniform and 

 the Sporotrichum so vigorous and ever- 

 present that the further watching of sep- 

 arate lots seemed useless. Accordingly 

 June 20th a large glass case was ar- 

 ranged with damp sand three inches 

 deep over the bottom. About ten dead 

 bugs covered with Sporotrichum were 

 scattered over the sand and large quan- 

 tities of live bugs from the field were 

 put in, with plenty of green wheat. In 

 nine days the bottom of the case was 

 thickly sprinkled with white fungus- 

 covered bugs and in thirteen days only 

 a few live bugs remained and the case 

 was restocked. The infection continued 

 to work so rapidly in this case that we 

 found no trouble in filling from it 

 twenty-five to one hundred orders daily. 

 Vast numbers of young red chinch bugs 

 were put into the case together with the 

 adults and they too were an easy prey 

 to the disease. Minute points of white 

 made their bodies conspicuous among 

 the larger flecks of white where the 

 adult bugs lay covered with Sporotri- 

 chum. 



On June 28th Emfiusa aphidis was 

 first noticed in the infecting case. Up 

 to this date it had not made its ap- 



