FORTY-FIRST ANNUAL REPORT. 89 



THE SAN JOSE SCALE. 



E. Wl DeGRAFF. 



The San Jose Scale was first described in 1890, by J. H. Comstock, 

 who was at that time investigating and describing the different insects 

 that were troubling the fruit growers in California. His attention was 

 brought to bear on this insect by the people of the Santa Clara Valley. 

 They were losing many trees and did not know the nature of the insect 

 or how to cope with it. 



It was noticed that in the localities where trees were planted that 

 had been imported from northern Japan, the effects were most serious. 

 So destructive was the pest around San Jose that the people began to 

 call it the San Jose Scale. The scale did not originate there, as many 

 people suppose, for its native home is in northern China. But it gained 

 its foothold in America at that place by being imported along with the 

 nursery stock that came from the above country. 



In 1893 some nursery men in New Jersey bought infected stock from 

 California. This gave the insect a foothold in the east. It then began 

 to spread westward from there and eastward from California. It is 

 now found in nearly every state in the Union and in southern Canada. 



A female scale in the Spring will give birth to about 400 young, half 

 of which are females. The young female has no wings or eyes but has 

 legs, antennae and a sucking beak called probosis. Soon after its birth it 

 begins to scramble around until it finds a suitable place on the bark into 

 which it sticks its beak and sucks up the sap. This also serves to 

 anchor it to that particular spot until death comes. When it has found 

 this spot and has fastened its beak into the bark, it curls its legs and 

 antennae around itself until it is almost circular in form and then be- 

 gins to excrete from every part of its body a waxy fluid, which in the 

 course of time becomes papery-like and acts as a sort of armor. 



The young male has eyes, wings, legs, antennae but no mouth parts 

 to speak of. Its purpose in life is to mature and mate with the female. 

 This it does when it is from 32 to 40 days old. It then dies. 



There are four generations a year. If each female gives birth to about 

 400 young there would be at the end of the year, if nothing happened, 

 a little over three and one-fifth billion scales which owed their origin 

 from the first female of the year. Fortunately for the fruit grower not 

 all of these live, but an idea of the uncommon prolificacy of this insect is 

 seen and it should act as a warning against inefficient spraying or lack 

 of attention given this destructive pest. 



To control the scale, spray with a solution of Lime and Sulphur but 

 spray thoroughly. Although the best time to spray is in the Spring 

 very good results have been obtained when fall spraying was done. The 

 reason for this is that as a rule the farmer or fruit grower has more 

 time and can spray more thoroughly in the Fall than in the Spring. 

 The main thing is to spray thoroughly and as often as possible. The 

 increase in perfect fruit will more thati balance the cost of the spray- 



