October, '22] schwing and hartung: beet leafhopper 365 



were removed, and soon recovered. Others continued to move, although 

 with less vigor, for three hours, and were then allowed to remain over 

 night in the water. The next morning practically all of them were 

 still alive, although they had been under water for 18 hours. This 

 indicated that flooding fields infested by these beetles would be useless as 

 a control measure. 



Dr. F. H. Chittenden, Bureau of Entomology, informs the writer 

 that on two occasions other species of Blapstinus have been destroyed 

 by poisoned baits used by employees engaged in Truck Crop Insect 

 Investigations. The first of these experiments was performed by Mr. 

 H. M. Russell in the spring of 1911 in combating an outbreak of cut- 

 worms on sugar beet in southern California. Bran, shorts and Paris 

 green were used in the preparation of this bait. It was applied May 

 1 and when the infested fields were examined later, in addition to an 

 abundance of dead cutworms, many Blapstinus beetles were found lying 

 dead beside the poisoned bait. 



UTILIZATION OF SYSTEMATIC OBSERVATIONS ON BEET 



LEAFHOPPER {EUTETTIX TEN ELLA BAKER) AND 



CURLY LEAF OF SUGAR BEETS 



By Edward A. Schwing, B.S. and William J. Hartung, B.S. 



Spreckels Agrictdtural Experiment Station 



Sugar companies demand information as to the number of beet leaf- 

 hoppers {Eutettix tenella Baker) present during the spring invasion of the 

 pest into the beet fields, and also at very frequent intervals, the extent 

 and progress of curly leaf (curly top or blight) which this insect trans- 

 mits. Reliable information must be at hand for economic reasons. 

 The desultory manner of gathering and recording this information in the 

 past, resulted in data of very little value to the sugar companies as a 

 reference to the average number of leafhoppers for a certain nimiber of 

 beets and the possibility of securing a marketable crop. During 1920, 

 the recording of information was put on a sound workable basis with all 

 of the essential facts and related data. The following headings were 

 found to be most satisfactory in tabulating the data : 



