THE INJUKIOUS SCALE INSECTS AND MEALY BUGS, &c. 259 
this the most effectual remedy for the Brown Peach Scale (Lecanium per- 
sicce), killing about 80 per cent, of the larv;u. 
This emulsion may also be used for spraying foliage for other as well 
as scale insects. For tender plants and unripe wood and foliage, about 
double the quantity of water should be added, but even then the mixture 
is apt to scorch. It is advisable, therefore, to test the effect of the 
emulsion on the foliage before making wholesale applications of it ; as it 
may be found necessary to considerably weaken it by the application of 
water. It should be borne in mind that a certain percentage of soap, 
paraffin, and water is more deadly in its effects upon plants than pure 
paraffin ; a fact abundantly proved in the experiments conducted at 
Woburn on the Currant Phytoptus. And, what is more, certain plants 
can withstand the application more than others, and it will be necessary 
to vary the strength of the emulsion to suit them. 
Whale oil and hard white laundry soap have been recommended for 
use in the preparation of this insecticide, but as soft soap finds greatest 
favour among English horticulturists, I see no valid reason why it 
should not be used. It mixes thoroughly well with paraffin, and does not 
solidify. 
No. 2. — Smith's Swift and Sure." 
This is a very effective insecticide for soft-bodied and unprotected 
scale and " mealy bug " ; but its effects upon the small shield-covered 
scales (Diaspinae) are of very little service. For hard-wooded plants 
without leaves it has been found most effectual when applied at a tem- 
perature of from 130° to 140° Fahr., and, for plants with leaves, heated to 
not more than 100° Fahr. 
No. S.— Fir-tree Oil. 
An old and well-tried remedy ; but like paraffin is apt to scorch or 
burn the foliage if applied in bright sunlight. If applied to foliage, the 
plants should receive a good syringing shortly after its application. But 
this need not be done when the application has been made on plants or 
trees without leaves. 
No. 4:.~Soft Soap. 
For " sponging" greenhouse plants this is a most efficacious remedy. 
For this purpose it is used in varying strengths of from 1 to 3 oz. per 
gallon of water. The weaker solution should be used for such tender 
plants as Eucharis, &c. 
For bark application only it may be used at a strength of 8 oz. to 
the gallon of water. For " Mussel Scale " infesting the trunk and main 
branches of Apple and Pear, as also for Gryptococcus fagi infesting Beech 
trunks, it has proved a complete success. 
In all cases it is best to dissolve the soap by boiling it in a quart of 
water, afterwards adding the full quantity. 
No. 5. — *' GisliursVs Cojnpouncl.'' 
This is an excellent compound, and for sponging " plants I have 
never found it excelled. I have also used it with excellent results on 
