CHAPTER XVI 



INSECTS INJURIOUS TO BEETS AND SPINACH * 



The Beet-aphis f 



THIS species was first described by Mr. W. R. Doane in 1900 

 and seems thus far to have been found only in Washington and 

 Oregon. " Attention was first called to this pest," he says,J " in 

 1896, when it was found that a field of two or three acres of beets 

 was generally infested, a strip of twenty-five to a hundred yards 

 being so badly injured that the beets were nearly all soft and 

 spongy, and the plants much smaller than the average. 



" It has been even more destructive in Oregon than in Wash- 

 ington, at least a thousand tons of beets having been destroyed by 

 it in one year in a single valley devoted largely to beet-culture. 

 Like very many other 

 beet-insects, this species 

 infests also several wild 

 or useless plants. 



" The smaller root- 

 lets of the beet are first 

 attacked by this aphis, 

 and if it occurs in con- 

 siderable numbers these 

 are soon all destroyed, 

 and the leaves thereupon 

 soon wither, and the 

 whole beet shrivels and 

 becomes spongy. This 

 wilting of the leaves will 

 frequently, in fact, be the first thing to attract the attention of the 

 beet-grower. The actual injury to the crop will, of course, depend 



* See Forbes and Hart, Bulletin 60, 111. Agr. Exp. Sta., and F. H. Chitten- 

 den, Bulletin 43, n. s., Div. Ent., U. S. Dept. Agr. 

 t Pemphigus betce Doane. Family Aphididcs. 

 1 Bulletin No. 42, Wash. Agr. Exp. Sta. 299 



FIG. 253. The beet-aphis (Pemphigus betce 

 Doane) : a, winged female ; 6, wingless fe- 

 male; c, antenna of winged female. (After 

 Doane.) 



