THE TOBACCO BUDWORM^ AND ITS CONTROL 

 IN THE SOUTHERN TOBACCO DISTRICTS/ 



A. C. Morgan, Entomologist, and F. L. McDonough/ Scientific Assistant, South- 

 ern Field Cro)) Insect Investiffatians, Bureau of Entomology. 



CONTENTS. 



Page. 



Description of the insect in its dif- 

 ferent stages 3 



Nature and extent of injury 4 



History and distribution in the 



United States ___. 4 



Seasonal history 5 



Page. 



Food plants 5 



Predacious and parasitic enemies 6 



Control measures 7 



Poison applications 7 



General recommendations 10 



ONE of the most important insect enemies of tobacco, particularly 

 in the i|South, is the tobacco budworm ( Fig. 1 ) . The presence of 

 this pest in tobacco fields, even in very small numbers, may result in 

 great damage to the crop. A thorough knowledge by the planter of 

 the correct methods of control of this insect therefore is essential, 

 especially in areas where the cultivation of tobacco for cigars is 

 practiced. 



Since the results of budworm attack on sun-grown and shade- 

 grown tobacco are the same, the control measures outlined herein 

 apply equally to both. 



DESCRIPTION OF THE INSECT IN ITS DIFFERENT 

 STAGES. 



The tobacco budworm passes through four distinct stages in the 

 course of its development — the egg, larva, pupa, and adult. The 

 eggs are small, whitish, nearly dome-shaped objects, measuring about 

 one-fiftieth of an inch in diameter. They are sculptured with radiat- 

 ing ribs and cross furrows. 



The larva or worm stage (Fig. 1, h, c) varies greatly in color. 

 The most common color is light green with paler stripes running 

 lengthwi.se of the body, but the color may vary from green to yel- 

 lowish, dark reddish brown, or even a very dark gray. Between 

 these extremes there are many combinations of colors. Small larvae 

 which have passed through only one or two molts are much lighter 

 in color than those which have fed more extensively and have cast 

 their skins a greater number of times. When first hatched the larva 

 measures about one-twentieth of an inch ; when full-grown and ready 



* (Chloridea) HeliotMs virescenx Fab. ; order Lepidoptera, family Noctuidae. It was 

 formerly known as Heliothis rhexiae S. & A. 



2 Revised by F. S. Chamberlin, scientific assistant. Southern Field Crop Insect Investi- 

 gations, Bureau of Entomology. 



3 Resigned October 31. 1919. 



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