EEPOET OF PROGRESS IK THE INVESTIGATION OF THE 

 COTTON BOLL WOEM. 



By F. W. Mally. 



LETTER OF SUBMITTAL. 



ShreveporTj La., October 9, 1891. 

 Sir : At your request I have hastily prepared a very brief and condensed summary 

 of this season's work, carried ou under your direction, upon the Cotton Boll Worm 

 (Heliothis armigera Hiibn.). 



All details as to experiments, observations, and special notes have been omitted, 

 as the summary was only to give an adequate idea of the present condition of the 

 investigation. 



Very respectfully, yours, 



F. W. Mally, 



Assistant. 

 Dr. C. V. Riley, 



Entomologist. 



GEOGRAPHICAL DISTRIBUTION AND DESTRTJCTIVENESS. 



The Boll Worm is found throughout the whole cotton region. Over the 

 greater portion of this area its injury is only slight and not worthy of spe- 

 cial economic consideration. The regions where special remedial or pre- 

 ventive measures are practicable comprise that portion of Texas included 

 by an irregular line drawn from Paris to Tyler, to Cameron, to Temple, 

 to Gainesville, to Paris. For Arkansas a narrow belt from Fort Smith 

 to Morrillton, to Little Rock, to the southeastern portion of the State 

 For the Indian Territory a strip running from Gainesville, Tex., to Fort 

 Smith, Ark. These are the areas of greatest destructiveness, and for 

 the whole area the injury may range from 10 to 15 per cent of the whole 

 crop. For certain counties the percentage of injury is greater. Again, 

 individual plantations may be almost wholly destroyed while a dozen 

 others adjoining may escape with only slight injury. The sensational 

 reports of damage are nearly always based upon these individual ex- 

 amples, and an accurate scientific estimate of the average for a county 

 or district is seldom made. The worst infested fields are, in most cases, 

 those which for some of many reasons which could be given in a de- 

 tailed report behind the others ; that is, late cotton. This makes them 



45 



