U. S. £>. A., B. E. But. 66, Part IV. Issued January 27, IdO©. 
SOME INSECTS INJURIOUS TO TRUCK CROPS. 
THE LEAFHOPPERS OF THE SUGAR BEET AND THEIR RELATION 
TO THE "CURLY-LEAF" CONDITION. 
By E. D. Ball, Ph. D., 
Special Field Agent. 
INTRODUCTION. 
Ever since the introduction of the sugar beet into the intermountain 
region more or less loss has resulted each season from a condition 
called "curly-leaf," or "blight.*' (See PL I, fig. 1, j; Pis. II, III; 
PL IV, fig. 1.) Around Grand Junction, Colo., the beet growers 
have suffered frequent losses from this source. Supt. George Austin, 
of the Utah Sugar Company, reported a serious loss around Lehi, 
Utah, in 1897. In 1903 the beet crop in Sevier Count} 7 , Utah, was 
somewhat injured, the next year the damage was worse and more 
widespread, while in 1905 it extended throughout the State of Utah 
and the adjoining portions of Colorado and Idaho. 
Until 1905 the condition had been looked upon as a result of some 
fungous or bacterial disease, or due to a soil or climatic condition. 
During that season it was noticed for the first time that a leafhopper 
(Eutettix tenella Baker) was present in large numbers in the fields 
where this damage was the worst, and the writer, in connection with 
his duties as entomologist of the Utah Agricultural Experiment Sta- 
tion, commenced an investigation of the insect and it> relation to the 
damage. It was then too late to work out its life history, so most 
attention was paid to a study of its relation to the " curly-leaf " condi- 
tion and to experiments with remedies. This investigation was con- 
tinued in 190G and 1907, in cooperation with the Bureau of Entomol- 
ogy, and the life history was worked out. Owing to the small num- 
ber of insects appearing these two seasons, little more was done with 
remedies, but many new facts were learned in regard to methods of 
attack and the causes of the injury. 
The writer's attention was first called to the "curly-leaf" in 
August, 1900, by Prof. F. H. Shaw, then chemist of the Grand Junc- 
tion (Colo.) Sugar Factory. A careful examination was made at 
this time and again in succeeding year-, but no explanation was found 
