34 



from the fire, and while hot pour it into the kerosene. Churn this 

 with a spray pump till it changes, first into a creamy, then into a 

 soft, butter-like mass. For use, take one part of this prepared 

 emulsion and thoroughly mix with nine parts of soft water by 

 churning it back into the pail, or whatever it may be in, through 

 the spray pump until it is thoroughly mixed, then apply to the 

 tree. This treatment in ordinary seasons should be made about 

 the loth of June, and a second one ten days or two weeks later. 



If the mechanical mixture be used instead, a special pump, 

 having two tanks, such as the " Kerowater," should be used, the 

 pump being adjusted so as to mix five per cent of the kerosene 

 with ninety-five per cent of water. The time of the treatments 

 should be the same as when kerosene emulsion is used. 



The San Jose Scale. 

 (Aspidiotus perniciosus Comst.) 

 This most serious of scale insects was first discovered in this 

 country in California, about 1870. It is probable that China is 

 its native home, and it has several times been received from there 

 on imported stock. In 1893 it appeared in Virginia, where it 

 seems to have been received from New Jersey. An investigation 

 in the latter State led to the discovery that two nurseries there had 

 about the year 1886 or 1887 introduced the " Kelsey " plum from 

 California, in the hope that it might be proof against the attacks 

 of the curculio. The trees thus obtained did not thrive (probably 

 because they were infested by this scale), and were ultimately 

 destroyed, but presumably not until the insect had spread from 

 them to other nursery stock. As both of these nurseries did a 

 large business, the scale was in this way scattered all over the 

 eastern and middle States before the danger was realized. As 

 many of the places to which the infested stock was sent were 

 nurseries, these in turn became infested, with the result that the 

 San Jose scale is now present in nearly every one of the United 

 States, as well as in Canada and other foreign countries. 



Life History. 

 The insect passes the winter under the scale, but it is probable 

 that both the adult and the very young insects die during this 

 period. In the spring those which are alive resume their feeding 

 and become full grown about the first or middle of June. The 

 production of young soon follows, these being born alive. When 

 the young first appear they are extremely minute, yellowish in 

 color, and with six legs. They crawl away from the parent scale 

 and move about for a day or two, then settle down, and, inserting 



