10 FARMERS’ BULLETIN 123. 
In orchards where spraying for the San Jose scale is unnecessary 
and where the oyster-shel! and scurfy scales are troublesome, specific 
treatments become desirable. There is considerable difference of 
opinion among entomologists as to the effectiveness of sprays applied 
during the dormant season to effect the destruction of the eggs. 
There is greater uniformity of opinion, however, as to the effective- 
ness of spraying shortly after the young have hatched and before 
there has been time for the formation of a thick protecting scale. 
Recent observations and experiments, especially those by Messrs. 
E. W. Scott and W. 8. Abbott in connection with the enforcement 
of the Insecticide Act of 1910, indicate that lime-sulphur wash is 
adequately effective against the oyster-sheil scale applied during the 
dormant season, exactly as is done for the control of the San Jose 
scale. The lime-sulphur wash appears to seal the eggs and young 
under the scale covering, and probably also acts as a deterrent to 
the settling of the young lice on the twigs and branches. The effect- 
iveness of such treatments, however, would probably vary with 
weather conditions which would tend to interfere with the ‘‘sealing”’ 
action of the wash. It is recommended, therefore, that orchardists 
use for the control of the oyster-shell and scurfy scales the lime- 
sulphur wash now in general use against the San Jose scale. A single 
dormant-tree treatment should be effective in controlling these 
three scale insect pests. It is essential, however, that very thorough 
applications be made, and in the case of large apple trees with a good 
deal of rough bark on the limbs and branches, this should be scraped 
off where practicable, smce many of the scale insects wul find protec- 
tion under the loose pieces of bark. 
If for any reason the dormant-tree treatment has not been satis- 
factory, as shown by the abundance of young scales hatching in the 
spring, an additional spraying, using kerosene emulsion or fish-oil 
soap wash, may be desirable, directed against the ‘‘lce” just 
hatched. The records of dates of hatching given under the remarks 
on life history for each species will indicate approximately when 
the young insects may be expected to appear, but this time may be 
accurately determimed by frequent examinations of infested trees. 
The very small, yellowish insects will be seen in numbers crawling 
over the limbs and branches in their efforts to find a suitable place 
for settling. In general, the young of both species will have hatched 
and settled, and may be effectively treated during the period of from 
one to three weeks following the blooming period of the apple, and 
from two to four weeks after the blooming period of the peach. It 
will be preferable, however, to determine positively the time of 
crawling of the young for the particular locality and food plant by 
actual observations. 
