APPE]¥DIX III. 



EEPORT OF J. P. STELLE. 



Sir : I have the honor to submit the following report of my experiments and obser- 

 vations as a special agent of the United States Entomological Commission engaged 

 in the work of investigating cotton insects under your direction : 



Having been assigned to duty in the State of Texas, I first established my head- 

 quarters at Calvert, in Robertson County, a point in the rich cotton-producing re- 

 gions of the Brazos Valley, exactly on the line of 31° north latitude. It has usually 

 been understood that the Cotton Worm makes its first appearance for the season in 

 Texas in the most southern counties where cotton is grown, but for this year the 

 rule does not seem to have held good, as it appeared in injurious numbers in Eobertson 

 County as early as at any other place in the State. Information of its early appear- 

 ance in this section influenced me in making choice of my location, and it eventu- 

 ally turned out a most fortunate choice, on account of being entirely above the line 

 of the heavy rains which visited Texas in the course of the summer. While the 

 counties along the Lower Brazos and Colorado were being drenched with rains daily, 

 Eobertson County was entirely exempt ; in fact, scarcely a drop of rain fell in this re- 

 gion between the 1st of July and the 1st of September, a circumstance greatly favor- 

 ing my field-work, as will be readily seen. 



Both the Cotton Worm {Aletia xylina) and the Boll Worm {ReliotMs armigera) 

 appeared on tbe lowland farms along the Brazos, in what planters would term injurious 

 numbers, about the 20th of July. The weather was quite warm at this time, and it 

 continued warm throughout the season, the thermometer usually marking from 90° to 

 95° Fahrenheit at 2 o'clock in the afternoon. This, with a gentle breeze from the south, 

 bringing up an atmosphere from the rain-belt, heavily charged with moisture, seemed 

 to give every condition favorable for a thrifty growth and quick transformation of 

 the insects. As a consequence brood succeeded brood with astonishing rapidity, 

 the worms spreading quickly to the uplands, and doing their work so effectually that 

 by the 1st -of September all the cotton fields where remedies had not been applied 

 were completely stripped of their leaves, with a very large per centum of the bolls 

 bored into. This cut short my operations at Calvert, and in order that I still might 

 have more time for field-work, I changed my location to San Marcos, in Hays 

 County, where the worms were then (September 1) just beginning to put in an inju- 

 rious appearance. Here I remained till the 15th of October, prosecuting my labors 

 under conditions reasonably favorable in every respect. 



Summing up the results of my investigations as secured in the lines laid down for 

 the government of my work, I may begin with what planters in many parts of the 

 South call 



COTTON BLIGHT. 



In some localities it is known as " sfcalk-rust,'' and in others as '^ root-rot," but cot- 

 ton blight seems to be the name by which it is most generally called in Texas, and I 

 think the same may be said for a majority of the other Cotton States. 



This trouble begins in the cotton field about with the earliest appearance of blooms, 

 and usually on uplands, though one occasionally meets with it in bottom plantations. 

 The first indication we have of its lu'esence is a sudden wilting of the plants, which, 

 up to this time, were to all appearances as healthy and vigorous as any in the field. 

 In the morning the plants are looking all right ; in the evening their leaves are seen 

 to be wilting ; to-morrow evening they are blackened and dry. Usually the earliest 

 attack is made upon only a few plants in a place, more commonly than otherwise 

 upon a single specimen. A week later, perhaps, and one of its nearest neighbors shows 

 symptoms of the blight, then another and another on till frost cuts short the growth 

 of the crop, when, in many cases, it will be seen that all the plants of a spot several 

 rods in extent have been ruinously blighted. The bolls that are at maturity when 

 the plant dies will open and show no particular damage, but the young bolls will dry 

 up and be lost. 



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