THE LIME-SULFUR WASH. 73 
with the uncertainty of composition. Nevertheless, where only a few 
trees are to be spra}^ed and the owners would probably not go to the 
trouble of preparing a standard emulsion or the lime-sulfur wash, the 
use of miscible oils or ready-made lime-sulfur washes is a good deal 
better than nothing, and may give very good results. Space does not 
permit the mention and discussion of a number of other mixtures which 
have not proven satisfactory nor the equal of standard means of 
control. Some of these have been experimented with somewhat 
extensively b}^ different experiment station entomologists. 
The methods of control which have been especially followed in the 
Eastern States are (1) the lime-sulfur wash, (2) the soap treatment, 
(3) treatment with pure kerosene, (4) treatment with crude petroleum, 
(5) treatment with mechanical mixtures of either of the last two oils 
with water, and (6) petroleum emulsion with soap. All of these 
methods have proved themselves to be successful against the San Jose 
scale when properly carried out. As compared with the lime-sulfur 
wash, the others mentioned are more expensive, and the two oils, 
unless very carefully applied, are likely to injure the treated plants 
and are now seldom used. One's choice of method must therefore be 
governed by availability, special needs, and experience. In the main 
these remedies, including the lime-sulfur wash, are winter treatments 
and ma} T be emplo} T ed at any time when the trees are in dormant, leaf- 
less condition. The weaker oil-water mixtures and the emulsions may, 
however, be used in the growing season. The treatments enumerated 
are all for trees in the orchard. ISTursery stock badly enough infested 
to require such treatment is best destro} T ed. For the general disinfec- 
tion of nurseiw stock the lrydrocj^anic-acid-gas treatment is the standard 
and only satisfactory means. 
THE LIME-SULFUR WASH. 
In California, where this scale insect first occurred, the standard 
remedy for it is the lime, sulfur, and salt wash, a mixture formerly 
used as a sheep dip in Australia and emploj^ed with little change against 
the San Jose scale, and by a lucky chance proving effective. This 
wash was naturall}^ first thought of on the discover}^ of the San Jose 
scale in eastern orchards. The earlier tests, however, conducted by 
this office in 1894:, were unfavorable, and the experimentation which 
followed resulted in the demonstration by ourselves and others of sev- 
eral distinct and valuable methods of control noted below. Later 
studies of the action of this wash in California led the writer in 1900 
to give it a further careful trial in the East, with most successful 
results, demonstrating that with favoring conditions, i. e., absence of 
dashing rains for a few days subsequent to the application, it would 
give just as good results in the Eastern States as on the Pacific coast. 
