.48- 
Material 
Spray schedule 
Apples wormy 
and stung 
Rotenone 1:1,670 
Lead arsenate 1:416 
Rotenone 1:4,200 
Load arsenate 3 
pounds per 100 
gallons 
Rotenone 1:4,450 
Lead arsenate 3 
pounds per 100 
gallons 
Calyx and first- coyer spray... 
of lead arsenate followed by- 
■6 cover sprays of rotenone 
Calyx and S coyer sprays 
Calyx and 3 cover sprays 
Tannic acid was added to 
first cover spray 
Calyx and 3 cover sprays 
Calyx spray of lead arsenate 
followed by 6 cover sprays 
of rotenone 
Calyx and 6 cover sprays 
Percent 
~70.4 
51.5 
' 41.5 
.9.3 
17.0 
2.5 
Those "who have tested rotenone in the field do not consider it a prom- 
ising substitute for lead arsenate, However, it is so effective in labor- 
atory experiments when' freshly applied that the possibility of its use in 
the field should not be abandoned until efforts have been made to under- 
stand and control its adherence and decomposition on fruit and foliage. 
Newcomer ( 306 ) in 1932 stated that pyrethrum had' been tested rather 
thoroughly but no Way had been found that would make it as effective as 
nicotine for control of this insect and the same might be said of rote- 
none. 
Newcomer and Yothers ( 507 ) in 1932 reported .that a commercial extract 
of derris [Derrisol?] was ineffective as an ovicide (1:800) and as a lar- 
vicidc (1:400). A mixture of 0,75 percent, of lubricating- oil emulsion and 
commercial derris extract (1:400 and 1:800 ) was ineffective in preventing 
the worms from entering sprayed fruit in laboratory experiments. An alco- 
holic extract of derris and a kerosene extract of pyrethrum in orchard 
experiments were practically worthless, the fruit becoming extremely wormy, 
This sample of derris root was later found to be low in total extract and 
to contain not more than traces of rotenone, which explains the very poor 
results obtained with it. An orchard experiment with the commercial', 
derris extract was discontinued because fruit and foliage injury developed 
and much of the fruit was becoming wormy. 
