UNITED STATES DEPARTMENT OF AGRICULTURE 
$Mk BULLETIN No. 427 ti^A 
^SY\rr^^ Contribution from the Bureau of Entomology ^&ywv«F* 
J&P m< ^U L. O. HOWARD, Chief j&?* < &2i. 
Washington, D. C. 
PROFESSIONAL PAPER 
February 6, 1917 
THE POTATO TUBER MOTH. 
By J. E. Graf, 1 Entomological Assistant, Truck Crop and Stored Product Insect Investi- 
gations. 
CONTENTS. 
Historical 
Distribution 
Possible origin . 
Nature of injury 
Economic importance 
Classification and synonymy . 
Description. 
Food plants 
Life history and habits 
Natural enemies and checks . 
Artificial control 
Summary 
Page. 
14 
15 
32 
48 
51 
Bibliography 52 
The account of the potato tuber moth (Phthorimaea operculella 
Zell.) given in the following pages is the result of an investigation 
of this insect carried on in southern California from 1912 to 1916. 2 
During the latter part of 1911 the late H. M. Russell conducted a 
few life-history experiments at Compton, Cal., but the work was not 
taken up as a special project until the following year. The laboratory 
work was conducted almost entirely at Whittier and Pasadena, 
Cal. The material for rearing and collection of parasites, however, 
was collected from the following counties: Los Angeles, Orange, 
Kiverside, San Bernardino, and Ventura. 
HISTORICAL. 
The tuber moth was first mentioned in literature by Capt. H. 
Berthon (l) 3 who described it /under the name of the " potato grub," 
as being very damaging to potatoes in Tasmania in 1854, and con- 
i Resigned Jan. 16, 191(5. 
2 The writer wishes to express his indebtedness to Dr. F. H. Chittenden for suggestions throughout the 
work, and for the use of notes from his files; practically all the data on the occurrence of the tuber moth 
within the United States outside of California being taken directly from his notes. 
Acknowledgment is due Mr.S.S. Rogers, Assistant Plant Pathologist of the University of California 
Experiment Station, for allowing the writer to collect data relative to the tuber moth in the experiment field 
at Van Nuys; to Mr. B. L. Boyden of the Bureau of Entomology, who conducted all the rearing experi- 
ments from December, 1913, to April, 1914, and to Mr. F. R. Cole for illustrations of the moth in its differ- 
ent stages and parasites, and for assistance in rearing. 
3 Figures in parentheses refer to similar numbers in the " Bibliography,'* p. 52. 
Note.— This bulletin is of interest to entomologists and to potato growers especially in the warmer 
sections of the country. 
-Bull. 427—17 1 
