UNITED STATES DEPARTMENT OF AGRICULTURE 



JV-^'^N-rt. 



1 BULLETIN No. 427 



Contribntion from the Bureau of Entomology 

 L. O. HOWARD, Chief 



jrC^^i. 



Washington, D. C. 



PROFESSIONAL PAPER 



February 6, 1917 



THE POTATO TUBER MOTH. 



By J. E. Graf/ Entomological Assistant, Truck Crop and Stored Product Insect Investi- 



■ gations. 



CONTENTS. 



Historical 1 



Distribution 2 



Possible origin 3 



Nature of injury 4 



Economic importance 6 



Classification and synonymy 9 



Description 9 



Food plants 14 



Life history and habits 15 



Natural enemies and checks 32 



Artificial control 48 



Summary 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 Cahfornia from 1912 to 1916.^ 



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, 

 collected from the following counties: Los Angeles, Orange, 



was 



Riverside, San Bernardino, and Ventura. 



HISTORICAL. 



The tuber moth was lirst mentioned in literature by Capt. H. 

 Berthon (1)'' who described it, under the name of the "potato grub," 

 as being very damaging to potatoes in Tasmania in 1854, and con- 



' Resigned Jan. 10, 1910. 



» The writer wishes to express his indebtednens to Dr. I'". II. Chitteiuion for suggestions thnmgliout the 

 work, and for the u.se of notes from his files; practically all the data on the occurrence of the tulx-r moth 

 within the l'nite<l States outside of California being taken direx'tly from his notes. 



Acknowledgment is due Mr.S.S. Uogers, Assistant I'lant Pathologist of the University of ( iilifornia 

 Experiment .Station, for allowing the writer to collM^t data relative to the tuber moth in the experiment (icid 

 at Van Nuys; to .Sfr. ». L. IJoyden of the Bureau of Kntomology, who conducted all the roaring exporl- 

 mcntsfrom December, 1913, to April, 1914, and to .Mr. I". K. Cole for iliusl rations of the moth in its dilfer- 

 ent stages and parasites, and for assistance Iti rearing. 



• Figures in parenthcse^s refer to similar numbers in th<5 " Bibliography,'- p. 52. 



N(>Tt.— This bulletin Is of Interest to entomologists and to potato growers especially in the warmer 

 aections of the country. 



56889*— Bull. 427—17 1 



