246 Journal of Agricultural Research vol. xx, No. 4 



The color variations in the fourth instar are similar to those of the third. A red 

 coloration is often observed. The spines on the legs are more conspicuous than 

 formerly, and the wing pads extend to the dorsal margin of the third abdominal 

 segment. Length 2.30 mm. 



After the fourth molt the nymph has a slender appearance and is nearly the size 

 of the adult. The wing pads extend approximately to the dorsal margin of the 

 fourth abdominal segment. Length 3.2 mm. 



ADULT 



In California, during the summer, adults of this species may be collected showing 

 a gradation in color from light green with no markings to dark gray with numerous 

 markings on the elytra (PI. 42, A-C). In the fall the percentage of dark forms 

 is much larger, and during the winter it is unusual to find a light form. Some of 

 the winter forms appear almost black. 



The following color details are given to show, to some extent, the extreme contrast 

 in coloration: 



Light form (PI. 42, A). — Front yellow, with faint, light brown, transverse stripes. 

 Eyes gray, with occasional brown spots. Vertex green and lemon yellow, the yellow 

 predominating. Pronotum green. Scutum deep yellow. Elytra hyaline with light 

 brown venation. No pigment in the elytra. Tergum appearing as dark bands 

 through the folded elytra. 



Dark form (PI. 42, B). — Frontyellow, with irregular, testaceous, transverse bands. 

 Eyes a mixture of red and brown, red usually predominating. Vertex fulvous, 

 apical portion with a white band cut in center by a narrow dark band. Pronotum 

 olive, except for ivory anterior band with several black spots. Scutellum with two 

 square, black spots at basal angles. Elytra subhyaline, marked with, black about 

 as follows: Two large, almost circular spots on corium; apical portion and irregular 

 black blotches on claval region. Nervures dark brown, with dark pigment on each 

 side forming irregular bands. 



RESEMIU.AXCE TO OTHER SPECIES 



There should be little difficulty in distinguishing the beet leaf hopper 

 from other leafhoppers commonly found on sugar beets in California. 

 Occasionally the darkest forms resemble some species of Agallia in 

 coloration, but even a superficial examination will be sufficient to sepa- 

 rate these two genera. These species of Agallia do not have the slender 

 appearance of the beet leafhopper and are much slower in their move- 

 ments. After a little experience in collecting it is possible to distinguish 

 between the two genera by their movements. Eutettix tenella rarely, 

 if ever, feigns death when disturbed; but some of the species of Agallia 

 are almost certain to fall over on their backs and lie for some time as 

 if dead. This habit is often an aid in collecting when the leafhoppers 

 are not abundant and a careful search is necessary. One species, Cica- 

 dula 6-notata Fallen, may often be confused with the beet leafhopper, 

 especially when individuals of the latter are mainly of the green colora- 

 tion. The six spots on the vertex of C. 6-notata are usually plainly 

 evident, however, and will serve to distinguish this species from 

 E. tenella. 



