^0. 1- ] ]\lifiet'Jl'iueiiux Noloft. 55 



whole as satisfaetoiy. The method adopted was very simple. It con- 

 sisted in shuttinti;- up healthy clinch bug's for a few hours in a jar con- 

 taining" diseased individuals. The insects thus infected were scattered 

 broadcast over fields infested with the pest, with the apparent result of a 

 g'reat spreading- of the disease and a consequent diminution in the num- 

 bers of the clinch bug's. The diseases which were disseminated were of 

 several kinds. They included a bacterial disease due to an oro-anism 

 identified as Ulicrococeits insectornm Burril, and at least two distinct 

 fungoid diseases. Of these diseases the Micrococcus has long- been known 

 to attack the clinch bug- [vide Cruickshank's Introduction to Practical 

 Bacteriology, London, 1886), and it is probably one of tlie most important. 

 It is described in a paper by Professor A. S. Forbes, quoted in Insect 

 Life, Vol. IV, p. 88. Professor Forbes found that it attacks a portion 

 of the digestive tract of the insect, and that, at one time, it was so 

 universally present that he was unable to find any unaffected clinch buo-s 

 for experiment in connection with the fresh inoculation of the disease. 

 This feature, in connection with the necessary liability to error in evi- 

 dence upon so technical a subject collected from farmers in the field, would 

 seem to indicate that the subject will require a good deal more in- 

 vestigation before any very certain conclusions will be justifiable as to 

 the practical results to be expected from the methods adopted by Mr. 

 Snow. In this connection Professor Forbes writes {North Amenca'n- 

 Practitioner, September 1891, quoted in Insect Life, Vol. IV, p, 88)— =• 



" Conceniing the utilization of artificial cultures of Micrococcus for a propagation 

 of this disease among insects not affected. I am at present able to say but little, as 

 I have not yet succeeded, in either season when it was common, in finding lots of 

 clinch bugs suflnciently free from it to make them suitable subjects for experimental 

 attempts at its transfer. It will be readily understood by any one that it is useless to 

 test the utility o£ artificial cultures of the disease germs by applying them to insects 

 which are already affected by the disease in question. The first step of any really 

 scientific investigation of the economics of this matter is to determine positively the 

 absence of the disease in the lots of insects to be used in the experiments. Every 

 lot of clinch bugs thus far obtained by me from Central, South Central, and Northern 

 Illinois during the months of July and August of this year, gave evidence, under 

 critical study, of the presence of this microbe in the coeca of a larger or smaller per- 

 centage of pupse and imagos. My previous observations — less carefully made, how- 

 ever, than my recent ones — have been to the general effect that hibernating clinch bugs 

 and young preceding the so-called pupa state are little liable to the spontaneous 

 occurrence of the intestinal trouble, and I consequently do not despair of finding, 

 before the present season is over, opportunity for experiments which will determine 

 beyond question the economic value of this clinch bug cliolera." 



The following extracts are taken from the reports of Mr. Snow^s 

 papers upon the subject as published in /;^5(?c^ J^'f^, Volumes III and 

 IV: — 



"As Entomologist to the Kansas State Board of Agriculture I had prepared an 

 article for the annual meeting of that Board in January 1889, stating what was 



