BULLETIN OF THE 



mmofAffldM 



No. 59 



ontribution from the Bureau of Entomology, L. O. Howard, Chief. 

 January 19, 1914. 



(PROFESSIONAL PAPER.) 



THE TOBACCO SPLITWORM. 



By A. C. Morgan and S. E. Crumb, 

 Of Southern Field Crop Insect Investigations, 



INTRODUCTION. 



The following account of the tobacco splitworm (PJithorimaea 

 operculella Zeller), although not complete, contains data not hereto- 

 fore published. The life history notes, description of stages, etc., 

 were made by the junior writer. Credit is due the senior writer 

 for the observations made in Florida and for the recommendations 

 under the heading: "Remedial measures." 



In California this insect is a serious potato pest, and Dr. F. H. 

 Chittenden ^ reports that in 1912 two growers at El Monte, Cal., 

 lost $90,000 and $70,000, respectively, on the crop of that year. 

 Although quite generally distributed over the Southern States, this 

 insect has caused serious loss to tobacco growers in only one locahty, 

 viz., Dade City, Fla. The injury at that place was severe in 1906^ 

 more severe in 1907, and culminated in 1908 in a conservatively 

 estmiated loss of $150 per acre — a loss totaling $12,000 for the 80 

 acres of shade-grown tobacco. The injury since 1908 has been very 

 light, due in part to the early planting and in part to the very careful 

 and very thorough remedial measures employed. 



The variation in food habits, which is noted later, had created the 

 suspicion that the form working upon potatoes might be specifically 

 distinct from the one attacking tobacco. During the summer of 1913 

 experiments were conducted to determine this point. 



EXPERIMENTS ON THE SPECIFIC STATUS OF THE TWO FORMS. 



The potato-tuber moths used in these experiments were of the 

 habitual potato-feeding type from Whittier, Cal., kindly furnished 

 by Mr. J. E. Graf. The splitworm moths were of the habitual 

 tobacco-feeding type from Florida, North Carolina, and Virginia. 



1 Chittenden, F. H., 1912. The potato-tuber moth. A preliminary account. {Phthorimaea operculella 



Zell.). U. S. Dept. Agr., Bur. Ent., Circ. 162, p. 2. Chittenden, F. H., 1913. The potato-tuber moth. 

 U. S. Dept. Agr., Farmers' Bui. 557, p. 2. 



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