CHINCH BUG WEST OF MISSISSIPPI RIVER. AT 
infested with chinch bugs, and it is on this fungus that most observa- 
tions have been made. 
The genus Sporotrichum includes a large number of fungi, the most 
of which are purely saprophytic (. e., living on dead animal or vege- 
table tissues). According to the best information obtainable, some 
of these are known to attack living tissues, causing their death, but 
afterwards developing rapidly on the body of the dead host. Sporo- 
trichum globuliferum belongs to the latter class, and is known to occur 
on insects belonging to the orders Coleoptera, Lepidoptera, He- 
miptera, and also on myriapods (centipedes and millipedes). It is 
credited with effectively attacking the elm leaf-beetle, the pupz and 
adults of which are found covered with the fungus, especially in late 
summer of a moist season.? 
Attempts have been made in most of the Central-western States 
to grow this fungus under artificial conditions, and then introduce 
it into fields badly infested with chinch bugs, where the fungus is 
not known to be present. With the possible exception of the Kansas 
experiments, made by Dr. Snow in the early nineties, these attempts 
met with little success. In most cases some unfortunate circum- 
stance always arose to make the success of the experiment uncertain. 
(This fungus requires rather cool, moist weather for most rapid 
development, and is present in greatest profusion when the bugs are 
exceedingly plentiful and massed together.) In many of the early 
attempts at artificial introduction, Entomophthora was present as 
well as Sporotrichum, thus giving rise to some confusion concerning 
just which fungus was credited with actually killmg the bugs. 
The most important of these experiments are fully set forth in 
the reports of the State entomologist of Illinois and in Bulletins 15 
and 69 and Circular 113 of this bureau, and therefore require no 
extended discussion here. 
OBSERVATIONS BY THE WRITERS. 
FIELD STUDIES IN KANSAS AND OKLAHOMA. 
It isfully realized by the writers that the determination of the cause 
of a disease is most difficult, and that it requires extended laboratory 
research along many different lines. To state that this fungous disease 
is the cause of the mortality among the chinch bugs, without this 
extended laboratory investigation, would be entirely unscientific. 
The observations given here are published for what they are worth. 
Observations on the habits and occurrence of the fungus were made 
in Kansas and Oklahoma during the spring of 1908 and 1909, and 
the spring and summer of 1910. Some additional data were obtained 
with respect to its behavior in the field among chinch bugs of all ages 

aConn. Agr. Exp. Sta., Bul. No. 155, 1907. 
