44 Farmers’ Bulletin 1128. 
QUASSIA AND FISH-OIL SOAP. 
Quassia extracts are used for destroying certain sucking insects, 
especially the plum or hop aphis. Solutions containing quassiin are 
more effective when combined with soap, which serves as a spreader 
and ‘‘sticker.’ Various formulas with different amounts of quassia _ 
chips and soap have been used, depending upon the insects to be — 
destroyed. The following formula gives a fairly strong spray solution: 
Quassia chips... ...-.- pS Se oe pounds.. 24,orpound.. } 
Hish-olsovper sepemias= to. sesccee= ees dOoe2) 0D) 4 Ob. td Onan 
WSteRs. oni. se eee tee int, os nie Sees ‘ile 50 , or oodles iad 
First dissolve the soap in a little hot water and pour into the 
container and then add sufficient water to make the total product 
equal to that given in the formula. Place the quassia chips (small 
chips are best) in cloth sacks and submerge in the soapy liquid for 24 
hours. The soap aids in extracting the quassiin. Instead of soaking 
the chips as above, they may be boiled in the same amount of soapy 
water for 4 to 5 hours. In order to extract a large percentage of the 
quassiin the full amount of the water indicated in the formulas 
should be used. Fruit growers will find no particular advantage in 
using quassia chips over nicotine solutions or kerosene emulsion. 
Quassia chips are not readily obtainable and the homemade extract, 
owing to its somewhat variable strength, is not always dependable. 
KEROSENE EMULSION. 
Kerosene emulsion has long served as a standard spray for control 
of soft-bodied sucking insects. If well made and properly diluted 
kerosene emulsion will give satisfactory results. Jt should never be 
combined with lime-sulphur. 
A good stock solution of kerosene emulsion containing 66 per cent 
of oil (by volume) may be made according to the following formula: 
Kerosene(coalsoil; dampreit): feet ee oe cree ane gallons. . 2 
Fish-oil or laundry soap (or 1 quart soft soap).........--- pound 4 
Witter 42.9705 Se SU ee ee Re cee neta ne ae gallon 1 
First dissolve the soap in boiling water; then remove the vessel 
from the fire. Immediately add the kerosene, and thoroughly agitate 
the mixture until a creamy solution results. The stock solution may 
be more conveniently made by pouring the mixture into the tank of 
a spray pump and pumping the liquid through the nozzle back into 
the tank for some minutes. The stock solution, if properly made, 
should last for some time, but it is better to make it up as needed. 
Do not dilute until ready to use. To make a 10 per cent spray (the 
strength for trees in foliage) add, for each gallon of the stock solution, 
about 52 gallons of water. Agitate the mixture in all cases after 
adding the water. 
