476 CALIFORNIA FRUITS: HOW TO GROW THEM 



ing with the natural green of the leaf. The branches are but little 

 troubled, but the fruit, like the leaf, becomes completely covered with 

 the insects. An orange tree infested with this scale gradually becomes 

 sickly and languishes. 



Other Citrus Tree Scales. Two scales more recently brought 

 into this State from Florida are the "purple scale," Lepidosaphes 

 beskii, and the "long scale," Lepidosaphes gloverii. The red and pur- 

 ple scales of citrus trees are only treated successfully by fumigation 

 with hydrocyanic acid gas. This treatment is an elaborate one, requir- 

 ing special appliances which are fully illustrated and described in 

 publications by the Agricultural Experiment Station at Berkeley: 



The Black Scale (Saissetia oleae}. This scale is almost a uni- 

 versal pest, especially in regions adjacent to the coast, though it has 

 recently demonstrated its ability to endure interior valley conditions. 

 It affects citrus fruit trees and some deciduous trees as well, and a 

 fungus growing on its exudation causes the black smut, which renders 

 tree and fruit unsightly ; but this smut accompanies other scale insects 

 as well as this one. It is especially troublesome on the olive, and will 

 quickly spread to ornamental plants and vines in the garden. It is a 

 very difficult scale to subdue. On citrus trees the fumigation method 

 is the only practical recourse. On deciduous fruits it requires both 

 winter and summer spraying to hold it in check. It spite of the fact 

 that immense numbers are killed by parasites, and perhaps by fungi as 

 well, it is still a grievous pest, and should be fought unceasingly. 



Soft Orange Scale (Coccus Hesperidum). This scale is a pest 

 of citrus trees the world over. The scale is ovoid, a little wider at 

 one end than the other ; length, from one-twelfth to one-seventh of an 

 inch ; color, dark brown on convex part, and a lighter brown surround- 

 ing margin ; it has two indentations on each side, and one on posterior 

 end. This scale prefers to collect on the under sides of the leaves 

 along the midrib, the upper sides being covered with smut. It for- 

 tunately is usually held in check by natural agencies. 



Brown Apricot Scale. The apricot tree, though defying the 

 most ruinous scales of some other trees, is beset by certain scales. 

 The black scale is one and the brown apricot scale another. The 

 brown apricot scale (Eulecanium Armeniacum) is boat-shaped; when 

 reaching maturity, wrinkled ; the color is a shiny brown, darker in 

 the center, lighter at the edges. A full-sized scale has a length of a 

 quarter of an inch, and a width of one-eighth of an inch. This scale 

 attacks nearly all kinds of deciduous fruits, but especially the prune 

 and apricot. It is a very hardy scale, and the remarks about the black 

 scale apply to it also. 



Other Lecaniums. There are several other scales on fruit trees ; 

 The filbert scale (hemisphericum) , which is common in greenhouses 

 and occurs to limited extent on citrus trees ; the frosted scale 

 (pruinosum), very large oval and convex, covered with dense, whitish 

 bloom, occurs on deciduous fruit trees. 



