JC OF AGRICULTURAL RESEARCH 



Vol. XX Washington, D. C, November 15, 1920 No. 4 



STUDIES ON THE LIFE HISTORY AND HABITS OF THE 

 BEET EEAFHOPPER 1 



[PRELIMINARY PAPER] 



By C. F. Stahl 



Scientific Assistant, Truck-Crop Insect Investigations, Bureau of Entomology, United 



States Department of Agriculture 



INTRODUCTION 



Much has been published concerning the distribution and history of 

 the beet leafhopper and its relation to the curly-top disease of sugar 

 beets, but no complete account of its life history and habits has appeared. 

 The present paper gives a brief summary of observations bearing on 

 these points made during the past few years at Jerome, Idaho, and in 

 the sugar-beet growing regions of California. 



DESCRIPTION 

 EGG 



The egg when first laid is transparent, elongate, and slightly curved. The pos- 

 terior end tapers gradually almost to a point. Length 0.0612 to 0.0696 mm. ; average 

 width 0.0182 mm. 



As the embryo develops, faint spots which later become conspicuous eye spots 

 appear on either side of the anterior end. During development the color of the egg 

 changes from white to lemon yellow with a slight tinge of green. 



NYMPH 



The recently hatched nymph is nearly transparent, with a light yellow tinge in 

 the thorax and abdomen. The antennae are hairlike and more than half as long as 

 the body. The head is wider than the thorax or abdomen and is the most distinc- 

 tive characteristic of this instar. 



After the first molt the nymph is more slender and the head and antennae are not 

 nearly so conspicuous. Average length 1.40 mm.; width 0.45 mm. Color usually 

 milky white with a green tinge. Faint brown blotches may be distinguished on 

 the thorax. 



In the third instar there is more variation in the coloring. General color varying 

 from yellow with light brown markings to almost black. The pattern made by the 

 brown blotches does not seem to be constant, but the denser coloration on the thorax 

 has been designated as a "saddle" (j, p. 21). 2 Length 1.99 mm. 



1 Euletlix lenella Baker, suborder Homoptera. family Jassidae. 



2 Reference is made by number (italic) to " Literature cited," p. 252. 



Journal of Agricultural Research, Vol. XX, No. 4 



Washington, D. C Nov. 15, 1920 



vk Key No. K-86 



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