INSECTICIDES AND EQUIPMENT FOR CONTROLLING INSECTS 2] 
San Jose scale, pear psylla, thistle aphid on prunes, fruit tree leaf 
roller, aphids, and spider mites. 
The oil is sometimes used in combination with dinitro compounds 
to facilitate control of certain pests, in which case less oil is used. 
Dormant oils meeting the above specifications may be purchased 
from most oil companies and then emulsified. For this purpose bor- 
deaux mixture, calcium caseinate, blood albumin, soybean flour, casein- 
ammonia, bentonite, or other emulsifiers may be used. Consult your 
State agricultural college, or county agricultural agent for directions. 
Dormant oils are also sold in a self-emulsifiable form ready for dilu- 
tion with water. 
White oils—White or summer oils are used in the control of the 
codling moth, spider mites, and leafhoppers on apples; scale insects, 
mealybugs, and the red spider and other mites on various ornamental 
and flowering plants; and the corn earworm on corn. Though some- 
times used alone, they generally are combined with sprays containing 
lead arsenate, pyrethrum, derris, cube, or nicotine. 
For most purposes the light oils of approximately 52 seconds vis- 
cosity (Saybolt, 100° F.) are preferred, but light-medium (about 63 
seconds viscosity) and medium (about 72 seconds viscosity) are also 
employed. For controlling the corn earworm on sweet corn a white 
mineral oi] of 100 to 150 seconds viscosity is used with pyrethrum 
extract. These oils should have not less than 85 percent of unsul- 
fonatable residue, and for use on tender plants they are usually diluted 
so that the final spray contains from 14 to 1 percent of oil. On shrubs 
and evergreens a 2-percent spray may be employed. 
White oil sprays act as adhesives, and when combined with arseni- 
cals they interfere with the removal of the poisonous residues. They 
may also cause injury to foliage and affect the coloration of apples 
if applied in too large quantities or too frequently. O7l sprays should 
not be applied to foliage on which residues from sulfur sprays are 
present, because severe burning may result. 
Summer oils may be emulsified with the same materials used to 
emulsify dormant oils, or with nicotine bentonite. They are, how- 
ever, most commonly sold as miscible or so-called “emulsible” oils con- 
taining about 97 percent of oil, or paste-type emulsions containing 
70 to 85 percent of oil. These contain emulsifying agents and need 
only be diluted with water. The manufacturers usually give full in- 
structions on the containers for use against various pests. 
The formulas given below have been found effective for use on 
ornamental plants. 
For red spiders: 
Derris or cube powder (4 percent of rotenone) ______ 1 tablespoonful. 
White oil emulsion (83 percent of oil)_-___-__-___- 4 teaspoonfuls. 
“YEU RES FSS os we ea See emer 1 gallon. 
For mealybugs and scale insects: 
Nicotine sulfate solution (40 eae of sucoane) ____ 1% teaspoonfuls. 
White oil emulsion_____ US SN ON es SE ee ee me: 3 tablespoonfuls. 
\1\) NES Ree es ee z ke =f gallon: 
For newly hatched scale insects on hardy shrubs and also against 
lacebugs: 
White oil emulsion (83 ae of om a _______ 1 eupful (or \% pint). 
Oa pte RCS or Cet eT es aR Decne 11% cupfuls. 
Nicotine sulfate solution________ ___ 4 teaspoonfuls. 
INGEYSEY aS SE ee eee ee ee Br, Uta hes a FT _.. 34% gallons. 
