The Bollworm or Corn Earworm. 



Fig. 4. — Bollworm motli with wings 

 folded in natural position. About 

 twice natural size. (Quaintance.) 



to the hardness of the soil. The overwintering pupDe are formed at 

 somewhat greater depths, usually 4 to 6 inches. These chrysalides 

 or pupae produce moths which in turn lay eggs, thus completing the 

 entire life cycle in about 30 days during warm weather. 



That there is a definite connec- 

 tion between weather conditions 

 and injury to the cotton crop by 

 this insect is generally recognized. 

 Cloudy and rainy weather dur- 

 ing the latter part of July and 

 throughout August undoubtedly is 

 conducive to severe injury. This 

 is partially explained b}- the moist- 

 ening of the soil, which permits 

 the moths to emerge without diffi- 

 culty, and by the stimulating 

 effect of the moisture on the growth 

 of stalks and leaves of cotton at 

 this time, which favors bollworm 

 development. Furthermore, it has 

 been found that the prevalence of such weather conditions lessens 

 the effectiveness of certain minute parasites which prey upon the 

 bollworm in the egg and larva stages. 



SEASONAL HISTORY AND RELATION OF ABUNDANCE TO CROP 

 GROWTH. 



As has been stated, the bollworm or corn earworm pupa passes 

 the winter months in the soil. Early in the spring the moths begin 

 to come out, and by the time corn is " knee high " they are ready 

 to deposit eggs. On account of the number 

 of pupse which die from adverse conditions 

 in the winter, the first generation usually 

 is small and the damage is not so appreci- 

 able. The second generation appears about 

 the time the com is in silk and tassel, and 

 the number of moths is increased greatly. 

 The caterpillars reach their full develop- 

 ment about the time the ears of early corn become hard. In the South 

 the third generation is the one which is destructive to cotton, the corn 

 at this time being for the most part hard and dry. In the North 

 this generation develops on late corn and other crops, and under usual 

 weather conditions is the last of the season, while in the South four 

 or even five generations may develop during a year. The late 

 caterpillars feed on various green crops, including late cotton, cow- 



FiG. 5. — Egg of bollworm 

 moth, side and top views. 

 Highly magnified. (Quaint- 

 ance and Brues.) 



