20 THE WHITE-FUNGUS DISEASE IN KANSAS. 
spores from the adjacent counties would be carried over into every 
field where they might alight. 
As will later be shown, Sporotrichum is not dependent on chinch 
bugs for hosts, but may live on other insects. There is hardly any 
question as to the presence of the fungus in the soil generally. 
Maintenance of Sporotrichum in the soil. — From the ease with 
which Sporotrichum is cultivated in the laboratory at room tem- 
perature with dead organic substances as culture media, it is possible 
that it propagates itself, at times, saprophytically in the soil. It is 
not dependent, however, either on dead organic matter or on living 
chinch bugs, but may live as a parasite on other insects, some of 
which are present in Kansas as permanent fauna. Various writers 
from widely separated localities have reported Sporotrichum on 
insects other than chinch bugs. While making no attempt to search 
for the fungus on other than chinch bugs, the writers noticed insects 
from time to time displaying the characteristic Sporotrichum 
growth. A list of them is given below. 
Insects upon which Sporotrichum has been Found. 
Three common snout beetles, Trichobaris texana, C onotrachelus 
erinaceus, and Anthonomus fulvus (PI. Ill, figs. 1, 2, and 3) ; a com- 
mon flea-beetle, Disonycha triangularis (PI. Ill, fig. 4;) a very com- 
mon lady-beetle, Hippodamia convergens (PL III, fig. 5) ; a minute 
beetle of the genus Olibrus (PI. Ill, fig. 6) ; and three true bugs 
belonging to the same order (Hemiptera) as the chinch bug, one 
a rather rare insect, belonging to the family Phymatidse, the species un- 
determined, and the other two common forms, Microtoma carbonaria 
and Coriscus ferus (PL IV, figs. 1, 2, and 3), and two unidentified 
larvae (PL IV, figs. 5 and 6) , and many common pentatomids. 
Natural Distribution of Sporotrichum in the Soil and its Kela- 
tion to Artificial Infection. 
The general distribution of Sporotrichum naturally in the soil 
might affect the artificial use of the fungus in one of two ways — by 
rendering it unnecessary, or by making it more effective. In the 
former instance a spontaneous outbreak would occur, which, if con- 
ditions were right, would be of such magnitude that, whatever man 
might do in the way of artificially distributing fungus spores, noth- 
ing appreciable would be added to the results ; or, given unfavorable 
conditions with a slight spontaneous outbreak, or none at all, artificial 
infection would not measurably spread the disease. In the second 
instance when there is already a spontaneous outbreak of considerable 
size, artificial infection might increase this to an epidemic that 
would end in a high percentage of mortality among the bugs. Other 
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