50 THE 'ill \cil BUG. 
tinued to die, none of those inclosed in dry environment wore destroyed. As the 
fungus had by this time bi te distributed over the experiment farm so that 1 
could not tell with certainty whether material from the fields was in a perfectly 
healthy condition or not, no further experiments were made in this direction. 
From the foregoing it will be observed that the essential element in all of 
these experiments was :m abundance of moisture, without which the Ento- 
mophthora could neither become established nor flourish after it had gained 
:t footing. Again, the extenl to which the disease will prove contagious will 
depend upon the number of bugs. Without great numbers massed together 
comparatively few would contract the disease. To sum up the matter, there is 
little h«>pe for relict' to the farmer from the influence of Entomophthora, except 
when chinch bugs are abundant and massed together in greal numbers, and 
during a period of we1 weather. I have succeeded in getting the fungus estab- 
lished at two widely located points in Indiana, and do not consider it at all 
difficult to introduce in localities where chinch bugs are abundant, provided 
the weather is favorable. But if it is ever utilized by the farmer, which seems 
p. me tn be at present .1 matter of considerable doubt, it will only be after 
the pesl has become very abundant, during the time between the first larval 
and adult stages and in a wet time. After the Entomophthora has been intro- 
duced int'> a certain held it will become diffused only in proportion as the 
bugs travel about and healthy bugs come in contact with spores from those 
which have died from the disease. This will not he very great until the pupal 
eached. 
The larva? of chinch bugs seem to in some way understand that while molting 
they will he well-nigh helpless, and hence hide themselves away in vast num- 
bers in secluded places. Under such conditions the spores thrown from dis- 
eased bugs would reach a larger number of their fellows. I have found adults 
hut recently molted affected by the Entomophthora. After the bugs acquire 
wings and scatter themselves over the country, the liability to contagion will be 
again reduced, unless in case of very severe invasions, where, from force of 
numbers, congregating on or about food plants becomes a necessity. Hence 
the introduction of the fungus among larva 1 will at first proceed hut slowly, 
and only in extreme cases and under favorable conditions can it he expected 
to proceed much more rapidly among adult hugs. In short, the only way that 
this fungoid disease seems capable of being employed in agriculture is by 
the establishment of some centra] propagating station to which farmers can 
apply and receive an abundant supply of infected bugs on short notice. By 
this mean- they could take advantage of a rainy period of a week or ten days. 
and. if they can contrive by sowing plats of millet and Hungarian to mas- 
the bugs iii certain localities aboul their fields, they might accomplish some- 
thing toward warding off an. invasion. But the possibility of overcoming an 
invasion after it is fully under way. as is almost sine to he the case during a 
dry season, it musl he confessed is not very encouraging. My failure after 
repeated experiments to produce this Entomophthora in the vicinity of Lafay- 
ette without the importation of germs i- decidedly against the theory that 
mighl he advanced that the northeastern portion of the State was kepi free of 
destructive invasions by reason of tins disease brought about by wel weather. 
There is as yet no reason to believe that the disease has ever existed in that 
section of the state. 
The fungus entering into these experiments was determined as an 
Entomophthora by Dr. J. C. Arthur, and the probability is that it 
was E. aphidis, though it is possible that Sporotrichum was also 
present and remained unobserved. 
