27 
tain kinds of Ichneumon flies (Ophion macrurum Linn.) are also de- 
stroyed by the gas. On one occasion I obtained a cluster of eggs of a 
species of Psocus fly (Cacilius aurantiacus Hagen) that were deposited 
upon a leaf of a tree before the latter had been treated with the gas, 
and from these eggs afterwards issued a number of parasitie flies be- 
longing to the family Proctotrupid and to the genus Alaptus; but the 
species is as yet undescribed. Various kinds of Lady-birds, which are 
in the tree when the latter is treated with the gas, become stupefied and 
fall to the ground, but finally recover and are to all appearance none 
the worse for their temporary loss of consciousness. Birds, lizards, and 
even barn-yard fowls sometimes refuse to leave the large orange trees 
while the tent is being let down over them at night, and are therefore 
inclosed in the tent and subjected to the gas; the latter proves fatal to 
all of these. The small, pale yellow mites which are frequently found 
on orange trees, especially beneath the dead scales, are not affected by 
the gas; these have a general resemblance to the young of the Red seale, 
and several operators, finding these mites still alive after the tree had 
been subjected to the gas, came to the erroneous conclusion that the 
gas had not been effectual, thinking that these mites were the young of 
the Red scale. 
From the above it will be seen that the gas treatment is not a sure 
specific for every kind of insect pest, but for destroying Red scales on 
citrus trees it is far superior to any other method at present known. 
THE RESIN WASH FOR THE SAN JOSE SCALE. 
During the past winter I carried on quite a series of experiments with 
various kinds of washes for the destruction of the San José scale 
(Aspidiotus perniciosus Comstock) on dormant deciduous trees, kindly 
placed at my disposal by Mr. C. H. Richardson, the inspector of fruit 
pests for the Pasadena district, Mr. Richardson also aiding me in mak- 
ing many of these experiments. Among all of the washes tried the fol- 
lowing gave the best results: 
IRESe ata tee scisie aie is aclaece male wancteisc se ace ees arene pounds.. 30 
Caustic sodan@i0sper: CENb) cea a. -ress aoe eee een == sees Ones 
INGO Gilles ds c6ec 6s ee peS ap eneee PeeHeeeean nopenonee ao ncre pints... 44 
Waterenough toimake -.)---- o-ssen eee eee Smee neallons.. 100 
For making 100 gallons of the above wash a kettle holding 30 gallons 
will be required. Place all of the ingredients in the kettle and cover 
with water to a depth of 4 or 5inches, boil briskly for about 2 hours, or 
until it will dilute evenly with water, like black coffee, which it closely 
resembles in color. When this stage is reached the kettle should be 
filled up with water, adding this very slowly at first; the contents of 
the kettle can then be emptied into a tank or other vessel, and a suffi- 
cient quantity of water added to make 100 gallons. Care should be 
taken not to chill the wash by adding large quantities of cold water at 
one time. 
