10 THE WHITE-FUNGUS DISEASE IN KANSAS. 
exception that the fungus was working as effectively in fields where 
none had been introduced as in fields where it had been artificially 
distributed. The fungus was found in every locality where the 
inspectors made observations. In commenting on this fact, Dr. Snow 
gad :*° 
Whether this widely extended natural presence of the Sporotrichum was the 
result of the general introduction of the infection throughout the State, in 1894, 
from the laboratory of this station it would not be possible with certainty either 
to affirm or deny. 
A full account of Dr. Snow’s work will be found in his six reports 
of the experiment station of the University of Kansas for the years 
1891, 1892, 1893, 1894, 1895, and 1896. The following is taken from 
his last report: 
’ 
RESULTS OF EXPERIMENTS FOR 10 years, 1888—1897.*" 
1. Chinch bugs in any of their stages of development scarcely run the slightest 
risk of death on account of heavy rains, even when these are of long duration, 
They are inconsiderably affected by extremes of heat and cold. 
2. We know of no contagious bacterial disease of the chinch bug. 
3. There are two parasitic, contagious, fungoid diseases that kill chinch bugs, 
namely, Sporoirichum globuliferum (“‘white fungus”) and Hmpusa aphidis 
(“gray fungus”). 
4. These two diseases show their greatest virulence where the ground is 
damp and shaded from the direct rays of the sun and the air is humid. 
5. We do not know to what extent the spores of these diseases are normally 
present in any given region. When they are present, whether naturally or 
artificially introduced, and the weather conditions are as given above, and the 
bugs are massed together, an outbreak of the diseases will occur. The number 
of chinch bugs killed in any field is approximately proportionate to the number 
of bugs in the field. ; 
6. Sporotrichum can be artificially communicated to healthy chinch bugs. 
(a) It attacks bugs of all ages, but the older the bug the more easily does iu 
succumb. (0b) Bugs of any age that have been weakened from any cause, or 
injured, fall more easy victims to the disease than do those individuals that 
are in perfect condition. (c) The adults of the second brood, which, in the 
ordinary course of events, winter over and lay the eggs for the brood of the 
succeeding spring, are much more successful in resisting the disease than are 
the adults of the first brood. (d) The fungus is not active in winter, and, 
though it be present with the bugs in their winter quarters, they do not die 
of it, even though the winter be as mild and humid as was that of 189596. 
The chinch bug seemed to have been almost exterminated in 1896 and there 
has not been any widespread outbreak since until the last two years, and 
hence little opportunity to investigate the practical value of the use of Sporo- 
trichum until this year. Many requests for the fungus were received at the 
university last year, but no provision was made by the university to supply it 
until this year, 
WORK IN OTHER STATES. 
The method of combating chinch bugs by the artificial distribution 
of infection has been extensively used in other States, but in most 
cases the practice has been abandoned. 
