Fifth Annual Report. a 
stronger bugs, but we have known the bugs in the larval state 
to die quite as rapidly as the more mature bugs. Mature bugs 
of the second brood in autumn and late summer show a remark- 
able resistance to the disease, but these yield to the disease 
after long confinement in the laboratory, and probably also in 
the field during the hibernation period if the meteorological con- 
ditions are favorable. 
6.—ARTIFICIAL CULTURES. 
This year, in addition to our old method of carrying on arti- 
ficial infection by fungus-covered bugs, we have used artificial 
cultures of Sporotrichum on various media, particularly on 
steamed potatoes and whole corn. The cultures were shaken 
up in water, and the water was applied by means of spraying 
machines. Experiments with this and with the old method 
gave contradictory results in the laboratory, but in the field we 
were unable to see any difference between the treated and un- 
treated fields, either when fungus-covered bugs or artificial cul- 
tures were used for infection, excepting in one experiment at 
the very outset of the year’s work; that is to say, during the 
spring months, when the weather conditions were unfavorable 
for the growth of Sporotrichum, the artificial dissemination of 
spores produced no results, while later in the season, when the 
conditions were more favorable, we found Sporotrichum abun- 
dant in the untreated as well as in the treated fields. 
7.—THE BARRIER METHOD. 
Since the experience of the past five years has taught us that 
there are always to be expected a varying percentage of failures 
in the use of Sporotrichum, we strongly urge that the farmers do 
not put their sole dependence upon this method, but that they 
also adopt the barrier method described later in this report. 
We have experimented the past season with this method suffi- 
ciently to be assured that it is a trustworthy defense at that 
very critical short period when the bugs are passing from the 
small grain into the corn-fields. With the plan of defense 
mapped out further on it should be the settled policy of the 
farmers not to let the bugs enter the corn. While the bugs are 
yet in the wheat and after they have scattered in the corn, and 
later when they have gone into winter quarters, almost our only 
