64 



INJURIOUS AND BENEFICIAL INSECTS OF CALIFORNIA. 



THE BEET LEAF-HOPPER 



Eutettix hurlln Baker 36 

 (Fig. 53) 



Description.— The adults are very small, pale yellowish-green or 

 almost white. The eggs are elongated, slightly curved, tapering at one 

 end and white. They are inserted into the leaf stems. The nymphs are 

 pale creamy-white with darker markings on the dorsum. 



Life History.— The females appear in the beet fields in June and 

 begin egg-laying the last of the month and continue until late in August. 



The eggs are usually thrust singly into 

 the tissues of the leaf petioles, where 

 they are often placed close together. 

 The eggs hatch in about two weeks 

 and the young begin to appear the 

 first part of July and continue in evi- 

 dence until September. By the last 

 of July adults appear, in which stage 

 the winter is passed. 



Nature of Work. — The "curly- 

 leaf" of the sugar beets is thought to 

 be caused or transmitted by this leaf- 

 hopper. The veins of the leaves 

 Fig. 53.— The beet leaf-hopper, thicken, nipple-like swellings appear 

 Entettix teneiia Baker. Nymph and on them and the leaves become 



adult greatly enlarged. (After Ball) 



severely curled and folded. In bad 

 cases the entire plants die, while in mild cases recovery is slow and the 

 the quality of the beets very poor. 



Distribution.— The species has been found in the central part of 

 the State, in the southern part, at Chino, San Bernardino County, 37 and 

 at San Diego County. It occurs widely over the State. 



Food Plants.— Dr. Ball records the following hosts: Atriplex, 

 sugar beets, Russian thistle, sea blite and Sarcobatus. 



Control. — Control measures are somewhat difficult. The applica- 

 tion of a dilute oil emulsion spray, to which § of a pint of 40 per cent 

 nicotine sulphate to every 100 gallons is added, will give good results 

 if applied as soon as the young begin to appear. Low hopper-dozers 

 will give fairly good results if used often. Early planting, to insure an 

 early vigorous top, enables the plants to more successfully resist attacks. 

 So far as known nothing tried has justified the cost. 



THE GRAPE LEAF-HOPPER 



Erythroneura comes (Say) 



i Typhlocyba pomes Say) 



(Fig. 54) 



Description. — The adults are very small, being scarcely more than 

 £ inch long. The color is somewhat variable. During the summer they 

 appear light yellow with the wing-covers mottled with faint red spots. 

 As the season advances the red areas increase in size until winter, the 



[•:. D., Bui. No. 66, pt. IV, Bur. Ent. U. S. Dept. Agric., 1909. 

 "Ball, E. D., Bui. No. 66, pt. IV, Bur. Ent. U. S. Dept. Agric, pp. 36 and 47, 1914. 



