-47- 
Hcadleo (185 ) in 1931 recorded tests with arsenical substitutes for 
the control of the codling moth. Four applications against first brood 
on early apples (Starr variety) gave the following percentages of infested 
fruit: Lead arsenate, 9.6; oil-pyrothrum, ll,4j' light oil-rotenone, 12.0; 
heavy oil-rotcnonc, 14.9; and tank-mixed nicotine tannate, 11.0. 
The Virginia Agricultural Experiment Station ( 458 ) in 1931 referred 
to the work of Kough to determine the difference between western and Vir- 
ginia strains in resistance to arsenical sprays. The results had indicated 
that tolerance to spray materials is not specific for arsenic, but also 
holds true for such insecticides as cryolite, barium fluosilicate, and 
rotenone. 
For control rotenone is considered as still in the experimental stage. 
— Anonymous (3) in 1932. 
Campbell (60) in 1932 critically reviewed all tests with rotenone. 
In all tests the apples were sprayed with suspensions of rotenone in water 
with or without the addition of other substances. Newcomer found that ro- 
tenone alone at 1:3,340 and 1:4,450 was decidedly more effective than lead 
arsenate at 2 pounds to 100 gallons (1:416) when the tests were made 
shortly after application of the spray, but the effectiveness of rotenone 
was markedly reduced when the tests were made 7 days after application; 
whereas the effectiveness of lead arsenate remained about the same. Kough 
noted the same phenomenon in a test of rotenone with Fenetrol. Of the 
larvae that hatched from 6 to 48 hours after the application of the spray, 
6,8 percent entered the fruit; of those that hatched from 48 to 72 hours 
after the application 25 percent entered. An experiment by Lathrop sup- 
ports results of Newcomer and Hough. Using a 1:4,450 suspension of ro- 
tenone, Lathrop found that 97.4 percent of the number of larvae that 
entered the untreated apples were prevented from entering apples freshly 
treated with rotenone. However, the efficiency of rotenone, when the lar- 
vae were placed on the fruit several days after treatment, was found to be 
only 32.5 percent. Newcomer also tested rotenone at 1:1,110 and found that 
the effectiveness of the deposit was greatly reduced in 7 days. 
In all tests by Newcomer and Hough the percentage of stings on apples 
treated with rotenone was lower than that on apples treated with lead ar- 
senate. In laboratory tests against this insect the addition of starch 
and glue as stickers reduced immediate effectiveness. The addition of 
mineral-oil and fish-oil emulsions to rotenone suspensions appeared to 
have no significant effect in immediate tests. In Hough's e: riment with 
rotenone ap excellent results were obtained 3 ' applica- 
tion of the spray. On the basis of total injuries, rotencne-soap v 
distinctly superior to the lead arsenate check. >ted that the a - 
dition of soap materially improved the distribution of rotenone. Several 
field tests have been made in the Pacific Nori er, obinson, 
and Spuler. Some results of such tests of roten .'. compi with 
lead arsenate are give" in the following table. T. was di - 
solved in acetone and the solution was add water to suspr 
