LEAFIIOPPKHS OF THE SUGAR BEET, 49 



OTHER LEAFHOPPERS. 



Seven species of leaf hoppers of the genus Entettix besides tenella 

 are known to have definite food phuits related to the sngar beot. and 

 several more, the food plant of which is not known, wnll probably be 

 found to have similar habits. All of these species wnll no doubt be 

 found on the sugar beet as fast as its cultivation is extended into the 

 regions where these insects occur. The following species of Entettix 

 are already known to occur on the beet, and are arranged in about 

 the order of their present importance. 



luitcttix strohi Fitch. — The nymphs of Entettix strohi are thickly 

 spotted with red, giving them a stronglj'^ reddish appearance. They 

 are found on Clienopodium alhimi (PI. T, fig. 2, a) and are confined 

 strictly to the underside of the leaf. The attack produces a red dis- 

 coloration and a curling of the leaf, which serves as a double protec- 

 tion for the insect. There are two broods in a season, the nymphs 

 appearing in late May and early June and maturing from the middle 

 of June into July. The adults of this brood are common from the 

 middle of June through July. Xymphs appear again late in July^ 

 from which adults appear late in August, and more commonl}^ in 

 September. This species was carefully studied through the first brood 

 in 190G. Then the area under observation was pastured and the 

 record lost. The Colorado records agree with last year's work for the 

 first brood, and furnish data for the second one. Prof. Herbert 

 Osborn " first called attention to the red coloring of the leaves. It 

 has been noticed many times since. This is, no doubt, the Allygus sp. 

 of Rruner.'' Forbes and Hart have mistaken the n3'mph for that of 

 PJilepsius irro7'atus Say." The larva of P. irro7'atus,hoyvever, is brown- 

 ish and fuscous and lives on the ground. Entettix strohi has been found 

 on beets (PI. T, fig. 2. h) in a number of places in Colorado and Utah, 

 nearly all of them, however, around the margins of fields. In one 

 ])lace the insects had appeared on the beets when they w^ere quite 

 small, and had been numerous enough to deform every leaf on a 

 numl)er of beets and entirely stop their growth. 



Entettix scitula Ball (PI. I, fig. 3). — Entettix .scitnla is a white 

 species with a brown saddle and brown pronotum. The nymphs are 

 of a powdery pink color and live on the underside of the Clieno- 

 podium leaf in the same way that those of Entettix strohi do, except 

 that the discolorations are lighter. This species is apparently 

 two-brooded. The first brood has been carefully worked out, but 

 only adults have been ob.served in the fall. The broods appear about 

 the same time as those of E. strohi. This is a western species occur- 



« Science Vol. X, i). Ififi, 18S7. 



"liul. 2.3, o. s., Div. Eiit., r. S. Dept, Ayric, p. IT, 1891. 

 ''Bui. GO, 111. Agrio. Exp. Sta., p. 424, 1900. 

 6G— IT 



