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13 
ing life history emphasizes the fact that it is necessary to do this very 
promptly, for the larvie remain in these situations a very short time, 
and early in May will have abandoned their burrows in the young 
shoots to transform, often elsewhere, although sometimes pupating in 
the withered leaves. The presence of dying terminals does not always 
indicate that a larva is necessarily present, since in many instances it 
will have wandered to some other point. With large orchards this 
step would be a very tedious one, and with trees of any size often 
impracticable. 
WINTER TREATMENT WITH KEROSENE EMULSION. 
The knowledge of the hibernating habits of this insect indicates a 
more effective method of control. This consists in spraying the trees 
during December or January, or any time after the foliage has fallen, 
with kerosene emulsion, resin wash, or some similar oily preparation 
which will penetrate the burrows and destroy the young larve. Mr. 
Ehrhorn found the kerosene treatment very satisfactory, as practiced 
in California in the winter of 1897-98, the little excremental pellets of 
the larve absorbing the oily mixture and leading it directly to the 
insect in its hibernating cell. For California Mr, Ehrhorn recommends 
that the application of the mixture should be begun in December. 
Kerosene emuision has one advantage over other oily preparations, 
such as the resin wash, in that it is more penetrating and will be more 
certain of reaching the larve. 
Where the emulsion is to be prepared by hand it is better to make it 
in rather small quantities at a time in order to secure a perfect combi- 
nation of oil and soap. The proportions usually taken are as follows: 
Kerosene, 2 gallons; whale-oil soap, half a pound; water, 1 gallon. 
The soap, first finely divided, is dissolved in the water by boiling and 
immediately added boiling hot, away from the fire, to the kerosene. 
The whole mixture is then agitated violently while hot by being 
pumped back upon itself with a force pump and direct discharge 
nozzle, throwing a strong stream, preferably one-eighth inch in diam- 
eter. After from three to five minutes’ pumping the emulsion should 
be perfect, and the mixture will have increased from one-third to one- 
half in bnlk and assumed the consistency of cream. Well made, the 
emulsion will keep indefinitely, and should be diluted only as wanted 
for use. 
For the treatment of large orchards, requiring large quantities of 
the emulsion, it may be advisable to prepare it with the aid of a steam 
or gasoline engine and suitable large tanks, as has been very success- 
fully and economically done in several instances, all the work of heat- 
ing, churning, etc., being accomplished by this means. When thus 
made the following proportions may be suggested: Kerosene, 10 gal- 
lons; whale-oil soap, 25 pounds; water, 5 gallons. As a winter wash 
the emulsion may be diluted with about six volumes of water, making for 
