91 
“Those taken out should then be scattered through the infested field 
where the bugs are thickest—at the bases of the leaves in the corn¬ 
fields, around the lower ends of the stalks, and the like. Make this dis¬ 
tribution, by preference, in the evening, when the dew is on, or, still 
better, just after a rain, and repeat, if dry weather follows. Continue 
these collections and distributions as above through the whole season, 
making certain each time chinch-bugs are taken out that white ones are 
left in the box; and when winter comes put all the dead bugs remain¬ 
ing into pill boxes for use the following year. 
“Those wishing to form an independent judgment of the practical 
value of this method of dealing with chinch-bugs should take into ac¬ 
count the following facts: 
“1. The white fungus causing insect disease requires moisture for its 
full development, and especially for the formation of the minute ‘spores’ 
by whose dispersal the disease is conveyed from one insect to another. 
In times of severe drought it propagates slowly or not at all. 
“2. It takes effect on a weakened insect more readily than on one in 
full vigor; on the full grown chinch-bug more easily than on the young; 
and hence most easily of all on spent adults which have already laid their 
eggs and are about to perish by the natural termination of their life 
period. 
“3. It is a native disease of the chinch-bug and never dies out en¬ 
tirely, but is likely to appear spontaneously over a large extent of coun¬ 
try when conditions favorable to its development are long maintained. 
4. Two generations of the chinch-bug appear each year, and when 
each of these generations matures, the adult bugs commonly take wing 
and scatter, thus disappearing largely from fields or parts of fields heavily 
infested by them. Such dispersal has often been mistaken for a destruc¬ 
tion of chinch-bugs by disease. One generation matures shortly after 
wheat harvest and the other in late summer and in the fall. 
“5. The chinch-bug sheds its skin four times while growing, and the 
empty skins left by it are often mistaken for dead bugs—a mistake 
which sometimes has led to a false conclusion as to the effect of these 
infection experiments. The cast skins never bear wings, as the insect 
does not moult after its wings are formed. They may be further readily 
distinguished from the dead bugs by the fact that when pressed between 
the thumb-nails they are readily seen to be shells without contents. 
“To judge intelligently of the effect of any attempt to introduce dis¬ 
ease, the observer should examine very carefully, in advance, the field in 
winch the experiment is to be tried, and adjacent fields as well, to see 
whether bugs dead with the white fungus may not already be present. 
It the disease appears at the point where the infected chinch-bugs are 
placed, he should repeat this general examination, and make sure that 
the disease may not have occurred spontaneously and without special 
reference to his experimental introduction of it. He should also notice 
whether young bugs (those without wings) are attacked by it, as, if they 
aye not, it is quite likely it is only carrying away those about to die of 
old age. On the other hand, it should be remembered that these espe- 
cially susceptible adult bugs may afford the best means of securing a gen- 
eial dissemination of the fungus in the fields, where it may lie dormant 
for a considerable time, ready to spring into sudden activity when favor¬ 
able weather conditions appear. 
• -^vantage should be taken of every considerable shower, and espe- 
cially of every long rain, to scatter the diseased bugs, and all fields under 
observation should be thoroughly inspected some two or three days there- 
£itL6r. 
I was also careful in every published statement or written com¬ 
munication on the subject to warn all against reliance upon this 
method to the neglect of other preventive or destructive measures, 
and emphasized in every way its purely experimental character. 
In the meantime, experiments, carefully planned and closely fol¬ 
lowed up, were made in the field through Mr. Marten and Mr. 
Johnson, both assistants of the office, by the distribution, in wheat 
