40 The Bulletin. 



upon the seed pods of the tobacco which is left for seed and, later, 

 upon the seed pods of the suckers which spring up in the field after 

 the tobacco is harvested. 



Life-history of the False Bud Worm. — The following account of the 

 life-history of the False Bud Worm is adapted mainly from the de- 

 tails given by Quaintance and Brues, 1 supplemented with such ob- 

 servations as we have been able to make in the field. There are evi- 

 dently several generations of the False Bud Worm each year. The 

 average length of the life cycle from egg to adult is slightly over 

 two months. The eggs are laid more commonly in corn and tobacco, 

 corn evidently being preferred above every other plant. The eggs 

 laid in corn are more commonly laid on the silk. The eggs hatch in 

 from two to eight days. The larvae become full grown in about a 

 month, when they burrow into the ground to a depth of from an 

 inch to seven inches, where they make a small cell, sparsely lined with 

 silk, in which they pupate. Moths emerge from these pupse in from 

 two to three weeks. 



Food Plants.- — The native food plant of the True Bud Worm seems 

 to be the ground cherry, or the horse nettle. Both these weeds are 

 often severely eaten in the field, and the True Bud Worm seems to 

 actually prefer these wild plants to tobacco. 



The False Bud Worm is a notorious general feeder, eating almost 

 anything that is green. It is a well-known pest of cotton, feeding on 

 the green bolls, hence it is known to the cotton farmer as the "boll 

 worm." On corn it prefers to feed on the green ears, hence it is known 

 as the "corn ear worm." Frequently, however, it feeds in the grow- 

 ing bud of corn and is generally known as "shatter worm." 



Control. 



Preventives. — As both the True and False Bud Worms seem to 

 prefer other food plants to tobacco, it is good policy to watch their food 

 plants in and about the tobacco field to see that they do not become 

 excessively abundant on these plants. The plants that should be 

 watched especially are the ground cherry and horse nettle for the 

 True Bud Worm, and corn and cotton for the False Bud Worm. 



Remedies. — In our field experiments at Stem, Granville County, 

 the plots sprayed with arsenate of lead at varying strengths from 3 

 to 6 pounds to 50 gallons of water were entirely protected against 

 these pests. In years when bud worms are not very abundant they 

 may be most easily controlled by hand picking. Quaintance gives 

 the following as a successful remedy used in Florida : 



The pest is much more satisfactorily controlled on tobacco than on most 

 other crops. A very usual practice, and one that has proven to be quite satis- 

 factory, is to sprinkle poisoned corn meal in the bud. This poison mixture 



bulletin 50. Bureau of Entomology, U. S. Department of Agriculture. 



