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16%: Contagious Diseases of the Chinch-bug. 
2.—SPOROTRICHUM AND EMPUSA. 
The causes of the known diseases of the chinch-bug are 
minute plants known as Sporotrichum and Empusa, or more 
popularly as the white and gray fungus or muscardine, respec- 
tively. They consist essentially of minute thread-like roots 
which penetrate the body of the bug and feed upon it, and the 
very minute branches produced on the outside of the bug and 
bearing small bodies in great abundance called spores. These 
spores germinate and produce new plants, thus serving the 
same purpose as the seeds of the higher plants. 
The spores are borne in minute bunches on the external 
branches somewhat like bunches of grapes. A single spore is 
only about ;>45> of an inch in diameter, and there are count- 
less numbers of these borne over the body of a single bug. 
Empusa, or the gray fungus, does not bear its spores in 
bunches, but singly, on comparatively large branches. 
These parasitic plants are called fungi, (singular, fungus,) 
and are not very distantly related to the rust of wheat and the 
mildew of potatoes, grapes, etc. 
It is seen that while some species of parasitic plants, such as 
wheat rust, potato mildew, etc., injure the farmer by destroying 
his crops, other species, such as Sporotrichum and Empusa, are 
helpful in that they destroy insects which eat up his crops. 
These low forms of plants flourish best in a humid atmosphere 
and in moist situations. They are even more sensitive to vari- 
ations in the weather than higher plants, because of their very 
diminutive size. 
With these considerations in mind it becomes evident that 
there can be no hope for success with Sporotrichum while the 
weather continues dry and hot, while on the other hand the 
very diminutive size of the spores and the vast numbers that 
are produced on a single bug would lead one to expect their 
very rapid and extensive dissemination when once present in a 
locality, and a general destruction of bugs when the conditions 
are favorable is therefore not surprising. 
During the past season we have found Empusa at times quite 
as destructive of chinch-bugs as Sporotrichum, indeed, later in 
the summer when the weather became excessively wet and 
cloudy, Empusa prevailed in some localities to the exclusion of 
Sporotrichum ; but Empusa cannot be so much depended on 
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