166 FRUIT INSECTS 



At Washington, the females may attain their full growth in 

 30 days from birth, but it requires about 50 days in the fall 

 in New York. As the females bear living young over so long a 

 period, the broods overlap and it is difficult to trace the number 

 of generations, but there are apparently three broods annually 

 in the latitude of New York and four broods at least south of 

 Washington. Breeding begins in the North in June and a 

 month or more earlier in the South. The progeny of a single 

 San Jose scale giving birth to only 100 female young in the 

 spring could, but doubtless never does, amount to the enor- 

 mous total of over 100,000,000 females by fall if there were four 

 generations annually. At this fearful rate of multiplication, 

 unequaled by any other injurious scale-insect, it is no wonder 

 that infested plants rapidly succumb to the drain of so many 

 thousands of tiny pumps sucking out their life. 



The widespread distribution of the San Jose scale is due 

 almost entirely to infested nursery stock. Rigid nursery 

 inspection, compulsory fumigation, and interstate quarantine 

 legislation doubtless help much, but fail to fully protect the 

 fruit-grower, and the pest continues to reach both old and new 

 localities on infested nursery stock bearing supposed " bills of 

 health " in the form of inspection and fumigation certificates. 

 Many have feared that new infestations might be brought about 

 through infested fruits, especially apples and pears, which are 

 distributed world-wide. Foreign nations enacted strict quar- 

 antine regulations against infested American fruit, even though 

 it were dried. However, there are no authentic cases of infes- 

 tation from scaly fruit, and while there is a bare possibility that 

 it might occur, the chances are so small as to be practically 

 ignored. The scale may be spread locally from tree to tree 

 or to other orchards in several ways. As the newly born lice 

 are active and often crawl about for a day before settling down, 

 they may be able to crawl on to other trees, especially in nur- 

 series where the branches interlace and touch. Strong winds 



