12 Farmers’ Bulletin 1169. 
cheapest of the scale-killing sprays, but unfortunately it discolors 
paints and, as most shade trees are located in greater or less proximity 
to buildings, its use is limited to trees not so located and to nursery 
stock. Wherever practicable to apply it with a paint brush, its 
cheapness may offset the labor cost. The concentrated preparation as 
bought should have a density of about 33° on the Baumé scale. At 
this strength it should be used at the rate of 1 pint in each gallon 
of spray. See Table I, page 30. 
MISCIBLE OR WATER-SOLUBLE OILS. 
In shade-tree work the miscible oils are used especially against 
scale insects and are the only ready-prepared substances available on 
the market that will effectively control all kinds of scales as does 
kerosene emulsion. These preparations come under a variety of pro- 
prietary names and vary somewhat in strength, so that directions for 
dilution as given on the containers must be followed carefully. The 
miscible oils are primarily winter sprays, being used at this season on 
account of the absence of foliage, which they are apt to injure. Since 
they are used principally in the control of scale insects, their appli- 
cation while the plants are dormant is most satisfactory anyway, 
because, in the absence of foliage, the insects are more easily reached, 
the covering with spray can be more complete, less spray solution is 
required, and the spray can be more safely applied at greater strengths, 
thereby killing the insects with greater certainty. 
CREOSOTE OIL. 
Creosote has been found very useful in daubing tussock-moth eggs. 
It is apt to thicken in cold weather and is then thinned with turpen- 
tine. 
KEROSENE. 
Kerosene is also useful on a mop at the end of a pole for daubing 
tent caterpillars and webworms or tussock-moth eggs, or, with proper 
caution, the kerosene on the mop may be lit and used as a torch to 
burn out the caterpillars in the tent or web. 
KEROSENE EMULSION. 
Kerosene emulsion is a standard contact spray, composed of kero- 
sene, soap, and water in certain proportions. By varying the pro- 
portion of water, this spray can be used both summer and winter 
against scales and soft-bodied insects. The emulsion, as the concen- 
trated mixture is called, is likely to deteriorate in storage, by break- 
ing up into the kerosene and soap solution from which it was made. 
For “ homemade ” emulsion the best procedure is to prepare a stock 
