156 
a little more carefully, and destroyed the majority of the young larvae. 
JBy the 19th of June all the fruit trees had been sprayed. The emul- 
sion used was made by emulsifying 1 gallon of kerosene and half a 
gallon of hot water in which one- fourth of a pound of soap had been 
dissolved, after which a sufficient quantity of cold water was added to 
make 15 gallons in all. This dilution was insisted upon, owing to the 
susceptibility of the peach foliage to strong mixtures. The cost of the 
emulsion so made amounted to half a cent per gallon. On June 19 
Mr. Coquillett was sent to Eiverside to ascertain the reason for the 
poor success of the previous sprayings. It was found that a Climax 
bucket pump and a knapsack sprayer had been used, and that the 
workman who operated the knapsack sprayer could not be induced to 
pull down the handle of the sprayer hard enough to make a good spray, 
since to do this it would be necessary to pull down with considerable 
force upon his own shoulders. With the bucket pump he did better 
work, but even here one side of the tree was usually slighted. The exper- 
iments showed that 1 gallon of diluted emulsion was sufficient to treat 
5 peach trees averaging 6 feet in height, and that one man could treat 
about 250 trees per day. On the 20th of June Mr. Coquillett had 26 
trees sprayed with a resin wash composed of 20 pounds of resin, 5 pounds 
of 70 per cent caustic soda, 2£ pounds of fish oil, and water to make 
100 gallons. This mixture was sprayed during the sunny part of the 
day upon trees treated with kerosene emulsion ten days previously, 
and resulted in the almost complete extermination of the insect. The 
resin wash was found to destroy the scales in a more advanced stage 
of development than the very dilute kerosene emulsion, while its work 
was more rapid. The rapidity of the work is of importance, since where 
a full grown female is sprayed with kerosene emulsion she may live 
for three or four days, during which time she brings young ; whereas, 
if sprayed with resin wash, fewer young scales are produced. The resin 
wash, however, is readily washed off' by the rains, while the kerosene is 
more resistant. On the 28th of June Mr. Coquillett was again sent to 
Eiverside and found that on the 26 trees treated with resin wash follow- 
ing kerosene emulsion absolutely all the scales were dead. In the mean- 
time the owner of the orchard had sprayed all the remaining fruit trees 
a second time with kerosene emulsion, an interval of ten days or more 
having elapsed between the two sprayings. Examination showed that 
very few of the older scales were still living, while more recently hatched 
individuals were almost as scarce as the traditional hen's teeth. On 
July 22 a final examination was made. No living insects could be found 
upon the trees treated with resin wash, and so few upon those treated 
with kerosene emulsion that a third spraying would have undoubtedly 
freed the trees from the insects. The owner, however, was unwilling to 
go to the expense of a third spraying, but promised to thoroughly apply 
a strong wash in the early winter. The owner of this orchard is a very 
busy man, with many other interests, and all the operations were under- 
