FIELD AND LABORATORY EXPERIMENTS IX INDIA. 
43 
Entomophthora were found in considerable numbers about hills of corn 2~> feet from 
■where the original colonies had been placed and also throughout and even 55 feet 
beyond the area of young wheat over which dead and affected bugs bad been dis- 
tributed. Daily observations were now made, bur the progress of th< -med 
t me to a standstill. From the ."th of August up to the Oth it was almost Impos- 
sible to get sufficient material, outside, to enable me to carry on laboratory experi- 
ments. August 13 the spread of Entomophthora appeared to have taken on new 
life, and diseased bugs were becoming much more numerous. August 15 found 
diseased bugs L72 feet from anyplace where they had been previously observed. 
August 20, diseased bugs were very abundant over all of the area where disease had 
been distributed, and two days later examples were found a quarter of a mile from 
the starting point of the disease. Immediately after this, however, another halt, 
both in the intensity of attack and rapidity with which it spread, due either to the 
dry weather or to the fact that the bugs had now all reached the adult stage and 
had become diffused over the country, no longer congregating together. From either 
one or the other, or both of these causes, I lost track of the Entomophthora and was 
not able to again rind it in the fields. It seems proper to state here that chinch bugs 
were not at any time excessively abundant. The greatest numbers were in the exact 
localities where the disease was first distributed, the congregating at these places 
being brought about by the close proximity to a large number of small experimental 
plats of wheat, and when this was harvested the bugs collected • >n the corn 
and young wheat. In connection with these facts, it is also interesting to note that 
from July 15 to August 31 there were ten days on which rain fell. The dates of these 
rains and the amount of precipitation is given below: 
Date. 
Precipi- 
tation. 
Date. 
Precipi- 
tation. 
JulvlT 
Inches. 
0.u2 
1.25 
.20 

.13 
July 29 
Inches. 

19 
22 
30 
Aug. 9 
.50 
3. 36 
- 
26 
^"13 
14 
.15 
.SB 
With a view of learning whether or not there was any difference as regard- - -- 
ceptibility to the attack of Entomophthora. befween bugs in different stages of 
development, a series of experiments was begun, as follows: 
Young plants of Setaria glauca were transplanted to a box. and upon each plant 
was placed a dead bug covered with the fungus, and al-o healthy Larvae : larva- just 
on the point of pupation : pupa' just prior to reaching the adult stage, and fully 
developed adults, each stage being placed on separate plants, and each covered with 
a small inverted glass vial designated by lettering. As checks, another series 
prepared, like the first in every particular. The soil in the box was kept well 
moistened, and the plants remained fresh. This experiment was made on Aug 
about the time when the attack outside began to diminish in intensity. The follow- 
ing are the results of examinations on the dates indicated, the original experiments 
being indicated by capitals and the checks by small letters, thus — A-a. adult: B-b, 
young larva- : C-c, older larvas j D-d, pup®. 
Date. 
A. 
a. 
B. 
b. 
c. 
* 
d. 
Aug. 5 
Aug. G 
Aug. 7 
Healthy . 
1 dead . . . 
All dead . 
All dead . 
Healthy .. 
1 dead '. . . . 
3 dead 
All dead.. 
Iloalthv . 
Healthv . 
3 dead *. . . 
All dead. 
Healthy . 
Healthy 
1 dead . . 
All dead. 
1 dead . . . 
1 dead ... 
3 deed ... 
All dead. 
Healtliv . 
Healthv . 
1 dead . . . 
1 dead . . . 
1 dead . . . 
1 dead. 
1 (lead. 
Aim. 16 
All dead. 
\ 
All.: 
On the same day this experiment was begun a second was also commenced, like 
the first in every particular, except that the healthy bugs used in experimentation 
