280 



different portions of the field of experiment would communicate the 

 disease more thoroughly while moving about among the healthy bugs 

 by which they would be surrounded. This belief was corroborated by 

 the results. The disease was successfully introduced from my labora- 

 tory into the States of Missouri, Nebraska, Indiana, Ohio, and Minne- 

 sota, and into various counties in the State of Kansas. A report of my 

 observations and experiments in 1889 has been published in the Trans- 

 actions of the Kansas Academy of Science, vol. xii, pp. 34-37, also in 

 the Eeport of the Proceedings of the Annual Meeting of the Kansas 

 State Board of Agriculture in January, 1890. 



The next point to be attained was the preservation of the disease 

 through the winter in order that it might be under my control and be 

 available for use in the season of 1890. To accomplish this result, I 

 placed fresh, healthy bugs in the infection jar late in November, 1889, 

 and was pleased to note that they contracted the disease and died in 

 the same way as in the earlier part of the season. I was not able to 

 obtain fresh material for the purpose of testing the vitality of the dis- 

 ease germs in the spring of 1890 until the month of April, and then only 

 a limited supply of live bugs could be secured. I quote the following 

 from my laboratory notes : 



April 10, twenty-five chinch bugs that had hibernated in the field were put in the 

 infection jars. They were supplied w^ith young wheat plants. The bugs appeared 

 lively and healthy. 



April 16, some of the bugs were dead and all appeared stupid. 



April 20, all of the bugs were dead. 



One week later a new supply of fourteen bugs was put into the jar ; they were sup- 

 plied with growing wheat. They ran substantially the same course as the first 

 twenty-five. Some had died at the end first week and all were dead by the end of 

 the thirteenth day. 



The chinch bug seemed to have been very generally exterminated in 

 Kansas in 1889 and only three applications for diseased bugs were re- 

 ceived in 1890 up to the middle of July. On account of the limited 

 amount of infection material on hand I required each applicant to send 

 me a box of live bugs, which I placed in the infection jars, returning in 

 a few days a portion of the sick bugs to the sender. The three appli- 

 cants above noted reported the complete success of the experiments. 

 I give the following letter from Mr. M. F. Mattocks, of Wauneta, Chau- 

 tauqua County, Kansas : 



Wauneta, Kansas, July 7, ls90. 

 Professor Snow, Lawrence, Kansas : 



Dear Sir : I received from you a few days since a box of diseased chinch bugs. I 

 treated them according to instructions, and I have watched them closely and find 

 that they have conveyed the disease almost all over my farm, and the bugs are dying 

 at a rapid rate. I have not found any dead bugs on farms adjoining me. I here in- 

 close you box of healthy bugs that I gathered l\ miles from my place. I do not think 

 they are diseased. 

 Yours, 



M. F. Mattocks. 



