December, '22] severin and basinger: beet leafhopper 411 



Sacramento Valley are favorable to the migrant and later generations in 

 the cultivated area. 



Since our investigations were conducted in the Sacramento Valley 

 during the past four successive outbreaks of the beet leafhopper from 

 1918-1921, we have no evidence to show whether the pest is found 

 only in this valley during periods of abundance as suggested by Ball (1). 

 Future observations will determine whether a migration takes place 

 into the Sacramento Valley in years when no general outbreak of the 

 beet leafhopper occurs. 



IX. Acknowledgments 

 We are deeply indebted to Mr. G. E. Springer, General Manager and 

 the Board of Directors of the Alameda and Union Sugar Companies for 

 employing Mr. A. J. Basinger and financing the work during the beet 

 season of 1920-1921. The Atriplexes were kindly determined by Dr. 

 H. M. Hall and the common names of the saltbushes used in this paper 

 will appear in a forthcoming monograph from the Carnegie Institution, 

 Washington, D. C. 



X. Bibliography 



1. Ball, E. D., 1917. The Beet Leafhopper and the Curly Leaf Disease that it 



Transmits. Utah Agr. Exp. Sta., Bui. 155, pp. 1-56. 



2. Severin, H. H. P., 1919. The Beet Leafhopper; A Report on Investigations 



into its Occurence in California. Facts about Sugar, VIII, No. 7, pp. 130- 

 131, 134; VIII, No. 8, pp. 150-151; VIII, No. 9, pp. 170-171, 173; VIII, 

 No. 10, pp. 190-191; VIII, No. 11, pp. 210-211; VIII, No. 12, pp. 230-231; 

 VIII, No. 13, pp. 250, 255. 



FACTS CONCERNING NATURAL BREEDING AREA OF BEET 



LEAFHOPPER (EUTETTIX TEN ELLA BAKER) IN SAN 



JOAQUIN VALLEY OF CALIFORNIA 



Henry H. P. Severin, Ph.D., California Agricultural Experiment Station 

 Almon J. Basinger, M. S., State of California, Department of Agriculture, Bureau of 



Pest Control 



I. Introduction 

 Sugar mills have been built in a natural breeding area of the beet 

 leafhopper (Euiettix tenella Baker) and in such localities the frequent 

 occurrence of curly leaf (curly top or blight) have closed the factories 

 after enormous losses have been sustained. In the San Joaquin Valley 

 four factories were erected in the natural breeding districts of this insect 

 and after the 1919 outbreak of the pest, three of these mills were closed 

 permanently. Since then the sugar mills at Corcoran and Visalia have 

 been dismantled and moved to Preston and Whitney, Idaho. 



