-60- 
calcium ar senate-treated plots. The DDT plots yielded 19 tons per acre 
whereas the caloium arsenate plots yielded 22 tons.— H. J. Agr. Expt. 
Sta. (275 ) . 
See Hellothls armigera .-- Tfolf enbarger et al . (379) • 
Mjyzus perslcae (Sul*.), the green peach aphid 
In -western Nebraska potato fields the aphid populations on DDT- 
treated plots remained at a level equal to or lower than that of the 
check plots. In contrast, the increases on plants treated with sine 
arsenite were highly significant. In repeated test6 under greenhouse 
conditions, heavy populations of Myzus persicae were eradicated with- 
in 48 hours with a 3-percent DDT dust. This species was unable to 
reestablish itself on suoh plants for some time afterwards. — Tate _et 
aj. (342) . 
Aphid populations on potato plants in plots treated with DDT dust 
or spray remained at a very low level in oontrast to narked increases 
on plants sprayed witti tine arsenite.— Hill (209) • 
Khopalosiphum prunlfoliae (Fitch) , the apple-grain aphid 
Sane as for Anuraphls roseus •— Baker and Porter (81) • 
Rhopaloslphum pseudobrassioae (Davis), the turnip aphid 
8ee Triohoplusia nl .~ H. J. Agr. Bxpt. Sta. (276 ) . 
Rhopaloslphum rufomacu latum Wilson, the green chrysanthemum aphid 
Acetone suspensions and Velsicol emulsions of DDT at 2 to 4 ounces 
of DDT per 100 imperial gallons of water gave 100 percent mortality, but 
powder suspensions killed only two-thirds of the aphids at 8 ounces of 
DDT per 100 imperial gallons*— Ross (306) * 
Sipha flava (Forbes), the yellow sugarcane aphid 
The aphid infestation was noticeably greater in DDT-treated plots 
than in plots receiving any other treatments or untreated.- Ingram jrt 
al . (222) | also Paokard (285) . 
Unidentified aphids 
A DDT-oil fog used to oontrol grape leafhoppers in Arisona did not 
kill aphids.— Vorhies and Wehrle (364) • 
