48 



ing to adhere in long serpentine strings of twenty to thirty or 

 more when actively dividing in liquids, and becoming short and 

 broad; with pale center, when forming spores, — this center being 

 simply the single unstained spore developed in each segment or 

 ■cell. 



The first examples of the entomophthorous infection certainly 

 seen in Illinois since 1882, were obtained by us from the corn 

 fields of Clinton county,* September 13, 1888, and the next, Sep- 

 tember 18, at Albion, where this fungous disease was, however, 

 less prevalent than that due to Botrytis. Its possible occurrence in 

 the Edgewood region was indicated by an accidental observation 

 made September 22. When examining a pupa obtained there on 

 the 8th of August, I found its fluids filled with fragments of the 

 entomophthorous mycelium. 



Letters and specimens from Minnesota and Iowa show the ex- 

 traordinary prevalence of this affection there, where it is evidently 

 the dominant chinch bug disease, — a condition in peculiar contrast 

 with that of the southern part of this State, where the Entomoph- 

 thora is relatively infrequent, and the Botrytis and bacterial dis- 

 eases are the prevailing maladies. 



Our first positive observation of the Botrytis disease of the 

 chinch bug was made, as has been said already, near Shattuc, 

 Clinton county, July 7, 1887. The specimens obtained were not 

 critically studied at the time, and the fungus was first positively 

 recognized as parasitic on the chinch bug August 7, 1888, on 

 specimens obtained at Flora, in Clay county. 



The occurrence of this disease on a scale suflficient to affect 

 notably the numbers of the chinch bug, was first observed Sep- 

 tember 18 by one of my assistants, Mr. John Marten, at Albion, 

 Edwards county. The insects were at this time much less numer- 

 ous there than three or four weeks before; in some neighborhoods 

 not more than one tenth as common. The apparent cause of this 

 decrease was a fungous disease, the mold-covered victims of which 

 were so freely sprinkled beneath the corn as to suggest a recent 

 flurry of snow. On one measured area, for example, of only two 

 square inches, twenty-six bugs were counted, covered with the 

 fungous growth — mostly that of Botrytis. Mr. William Over, a 

 local correspondent of the office, reported that this affection of the 

 chinch bug was observed there at oats harvest. 



The same Botrytis was detected in chinch bugs at Ashley and 

 Nashville, in Washington county, September 18. It occurred 

 freely in our breeding cages, where living chinch bugs were kept 



•Notes made In the fields of this region July 24, 1888, make It probable that the befflnnlngs of 

 this disease were obaerved at that time, although the specimens collected show only the Hotrytls, 

 The occ^r^en(^e waa recorded, however, of numerous dead bugs, adults and i>upie, Imbedded In a 

 fungus resembling that of inuscardlne, sometimes fastened to the leaves, sometimes beneath the 

 sheaths, and occasionally In the »llrt, as if they had been washed down by rains. In two eases, bugg 

 were attached to the leaves by a scanty mycelium, the insects themselves showing little external 

 fungous growth. This latter appearance is (piite characteristic of Entomophthora, lOven as far 

 hack as Vfarch IKH7. T noticed at llighiand. In Madison county, that fully half of the chinch bngt 

 lu errasa upon the headlands of fleldaof corn were dead, and usually covered with mold. 



