63 



are abundant and massed together in great numbers, and during a 

 period of wet 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 abun- 

 dant, provided the weather is favorable. But if it is ever utilized by 

 the farmer, which seems to me to be at present a matter of considerable 

 doubt, it will only be after the pest has become very abundant, during the 

 time between the first larval and adult stages and in a wet time. After 

 the Entomophthora has been introduced into a certain field it will be- 

 come 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 be very great until the pupal stage is reached. 



The larvae of Chinch Bugs seem to in some way understand that while 

 moulting they will be well nigh helpless, and hence hide themselves away 

 in vast numbers in secluded places. Under such conditions the spores 

 thrown from diseased bugs would reach a larger number of their fellows. 

 I have found adults but recently moulted 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 larvse will at first proceed but slowly, and only in extreme cases 

 and under favorable conditions can it be expected to proceed much more 

 rapidly among adult bugs. In short, the only way that this fungoid 

 disease seems capable of being employed in agriculture is by the estab- 

 lishment of some central propagating station to which farmers can apply 

 and receive an abundant supply of infested bugs on short notice. By 

 this means 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 Hun- 

 garian to mass the bugs in certain localities about their fields, they 

 might accomplish something towards warding off an invasion. But 

 the possibility of overcoming an invasion after it is fully under way, 

 as is almost sure to be the case during a dry season, it must be con- 

 fessed is not very encouraging. My failure after repeated experiments 

 to produce this Entomophthora in the vicinity of Lafayette without the 

 importation of germs is decidedly against the theory that might be ad- 

 vanced that the northeastern portion of the State was kept free of 

 destructive invasions by reason of this disease brought about by wet 

 weather. There is as yet no reason to believe that the disease has 

 ever existed in that section of the State. 



Before leaving the subject it will be proper to state that in my exper- 

 iments a larva of Chrysopa was introduced by accident and passed 

 through the larval stage, feeding continually on bugs dying from the 

 effects of the fungus. 



After harvest the Chinch Bugs, as usual, transferred their attention 

 to various grasses which were growing up among the stubble, more 

 especially Setaria and Panicnm, but as these succumbed to their contiu- 



