﻿UNITED STATES DEPARTMENT OF AGRICULTURE 



In Cooperation with the Bureau of Plant Industry 

 Pennsylvania Department of Agriculture 



DEPARTMENT BULLETIN No. 1357 



Washington, D. C. 



Januai7, 1926 



THE STRAWBERRY ROOTWORM, A NEW PEST ON GREENHOUSE ROSES ^ 



By C. A. Weigel, Associate Entomologist, Fruit Insect Investigations, Bureau 



of Entomology 



CONTENTS 



Page 



Systematic history 2 



Economic liistory and food plants 3 



Recent injury in greenhouses 4 



Distribution 6 



Nature of injury and economic im- 

 portance 6 



Life history and habits 8 



Page 



Seasonal history 25 



Natural enemies 27 



Experiments in control 27 



Preventive measures 44 



Summary 45 



Recommendations for control 46 



Literature cited 47 



During the last 40 years the native insect known as the straw- 

 berry rootworm, or strawberry leaf beetle, Paria canella (Fab.), 

 varieties quadrinotata (Say) and gilvipes (Crotch), was considered 

 a serious enemy of strawberry, raspberry, and a few other plants 

 only. Suddenly this little beetle appeared in greenhouses, attack- 

 ing roses in Virginia, Indiana, New Jersey, Pennsylvania, and Mary- 

 land. Prior to 1916 a suggestion that this insect would abandon its 

 usual hosts {29, p. 67Y for the succulent rose might have been sub- 

 ject to considerable doubt; but when simultaneous reports were re- 

 ceived by the Bureau of Entomology concerning two widely sepa- 

 rated infestations of an insect injuring roses in greenhouses at Alex- 

 andria, Va., and Richmond, Ind., such doubts would have been dis- 

 pelled, because an examination of the specimens which accompanied 



' The account of the strawberry rootworm and its control contained in this bulletin is 

 the result of an investigation started In .Tuly, 1919, when the first reports were received 

 by the Bureau of Entomology concerning injury by this insect to greenhouse roses. B. L. 

 Chambers assisted in the work until August," lf520, and C. F. Doucette from .Tanuary, 

 1921, until It was completed. Through thf courtesy of T. G. Sanders, then director of 

 the bureau of plant industry, Pennsylvania Department of Agriculture, a large portion of 

 the work was done In cooperation with that bureau with lieadquarters at Doylestown, Pa. 

 Credit Is due .T. K. Prirnm and A. W. Buckman. of the Pennsylvania Bureau of Plant 

 Industry, and also Miss B. M. Broadbent and A. T. Grimes, of the Bureau of Entomology, 

 for the assistance which they rendered at Intervals In the work. Figures .3, 4, 7, 8, and 9 

 were prepared by Miss AImi5 Motter. Special thanks are accorded to .Tohn A. Andre, of 

 Doylestown, for providing lal>oratory space, plants, and facilities for carrying on the 

 work, as well as to other florists who offered MSsistance. The writer Is also Indebted to 

 Prof. Herbert Osborn, of Ohio State University, for his interest, advice, and encourage- 

 ment tliroughout the progress of the work. Acknowledgment is given to Dr. A. L. Qualnt- 

 ancf» and E. R. Rasscor, of the Bureau of Entomology, for their many valuable suggestions. 



* Figures in italics In parenthefleB refer to " Ivlterattiro cited," p. 47, 



52018—26 1 



