16 



difficult to distinguish without a magnifying glass. The gen- 

 eral appearance which they present is of a grayish, very 

 slightly roughened scurfy deposit. (Fig. ii.) The natural rich 

 reddish color of the limbs of the peach and apple is quite 

 obscured when these trees 

 are thickly infested, and they 

 have then every appearance 

 of being coated with lime or 

 ashes. When the scales are 

 crushed by scraping, a yel- 

 lowish oily liquid will appear, 

 resulting from the crushing 

 of the soft yellow insects be- 

 neath the scales, and this 

 will at once indicate to one 

 who is not familiar with their 

 appearance the existence of 

 healthy living scales on the 

 trees." 



The young scale lice hatch Fig. n. San Jose Scale : Apple Branch, 



with scales in situ — natural size ; en- 



from eggs beneath the female larged scales above, at left. 

 scales, in spring, soon after the unfolding of the leaves. They 

 are minute yellowish creatures, resembling Fig. 12 when highly 

 magnified ; they crawl about over the bark a short time, and 

 finally fasten themselves to it, generally on the new growth, 

 where they secrete a scale and there develop. Some of them 

 mature into little two-winged creatures, resembling, when mag- 

 nified, Fig. 14 ; these are the males : others develop into females, 

 which do not become winged but remain on the bark in a fixed 

 position. In the bodies of these the young are produced, as 

 shown in Fig. 13. 



When the San Jos^ scale occurs upon older trees, it is most 

 likely to be found on the twigs and smaller limbs, but upon 

 young trees it may occur over the whole surface. But it does 

 not confine its attacks to the bark, for the leaves and fruit are 

 often infested : upon the latter there is a very characteristic 

 purplish ring around each scale. These rings are well illus- 

 trated in Fig. 10. " Upon the leaves the insects have a tendency 



