67 



other sources from which they could have come, viz, the stubble, which 

 I kuow to have been infested, and grasses, which we have no knowledge 

 of the species affecting. 



These plats were plowed up soon after examination, as I was afraid 

 to allow them to stand thus, a menace to the adjoining fields the follow- 

 ing spring, though the plants would have probably been destroyed 

 before even a small portion of the larvae matured. 



From all the information that I am able to gather, the usual time of 

 appearance of the fall brood of adult flies in southern Indiana is the 

 last portion of September, or some years the first days of October. 

 This is, I believe, the opinion of the most observing farmers, including 

 Hon. J. Q. A. Seig, of Corydon, Harrison County, who is as familiar 

 with the earlier stages of the pest and its effect upon fall wheat as I 

 am myself. Mr. J. P. Louden, of Sharp's Mills, same county, stated 

 that wheat sown on October 1, 1886, was damaged 50 per cent., while 

 that sown on the 6th was iDj'ured only 15 per cent. Mr. J. A. Burton, 

 writing from Mitchell, Lawrence County, November 24, 1887, gave the 

 results of his examination of wheatfields as follows : Fields sown Sep- 

 tember 8, about one plant in 8 infested ; sown September 15, about 

 one plant in 12 ; sown September 22, about one plant in 50, and 

 sown October 1, seemingly free from injury. The observations of these 

 gentlemen also coincide with my own, made in November, 1888, in Har- 

 rison and Posey Counties. Therefore, from all the information which 

 I have been able to gain, the best season for wheat sowing, to avoid the 

 attacks of the Hessian fly in extreme southern Indiana, is soon after 

 the 1st of October. Exactly how far northward this advice will apply 

 I am unable to say, but am inclined to think it would cover territory 

 laying between latitude 38° and 39°, and possibly 39° 30', although 

 near the northern limit it would probably be safe during ordinary years 

 to sow soon after September 25. 



During the years 1887 and 1888 Mr. W. S. Eatliff made a large num- 

 ber of very careful observations, and sowed a series of plats of wheat 

 on different dates near Eichmond, Ind. In 1887 plats were sown August 

 5 and 29, September 12 and 26. All of these plats were attacked and 

 more or less injured except the last, which as late as December 19 

 showed not the least injury by the Hessian fly. Up to May 31, 1888, 

 there was very little injury to this plat, and even on the above date 

 there were very few larva3 as compared with the number on the others. 

 From this date on till July 11 the plats were all injured by black and 

 red rusts, Chinch bugs, and the Wheat Stem maggot, the greater injury 

 appearing to fail upon this, so that at harvest, July 11, the last was 

 the poorest of all in yield, that sown August 15 being the best. The 

 sowings of 1888 were as follows : September 6, 20 ; October 4, 22; No- 

 vember 1. On November 14 the first plat was found to be infested by 

 larvse of the Hessian fly. During June, 1889, Chinch bugs again at- 

 tacked the plants growing on these plats, and the grain aphis seriously 



