VARIOUS SCALE INSECTS 



563 



scale is that of the female, the elongated one with ridges is the 

 male. The rose scale infests, besides roses, various fruit bushes, 

 especially blackberries and raspberries. Remedy : For raspberries 

 and blackberries the cutting down of the canes to the ground should 

 be adopted, and the stumps sprayed or washed with kerosene emul- 

 sion, recommended under the head of general remedies for scale 

 insects. 



Oleander Scale. (Aspidiotus hederac.) This scale is small, flat, 

 yellowish-white. It affects a great many trees, especially ever- 

 greens. Lemon trees become badly affected, and the fruit is some- 

 times completely covered. The olive is also subject, and the fruit 

 of the olive when infested does not mature well, and wherever a 

 scale is found, a green blotch makes its appearance. 



Red Scale of Orange and Lemon (Chrysomphales aurantii). 

 This scale affects citrus trees' in both the coast and interior regions. 

 The scale fully grown is one-twelfth of an inch or a little more in 

 diameter, center yellow, margin light brown. The appearance of 

 trees infested with this pest is very striking, very much resembling 

 those diseased from other causes, such as bad drainage, the leaf 

 presenting a mottled appearance, a light blotch around the scale 

 contrasting 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," Lepidosaphcs 

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

 ple scales of citrus trees are only treated successfully by fumiga- 

 tion with hydrocyanic acid gas. This treatment is an elaborate 

 one, requiring special appliances which are fully illustrated and 

 described in Bulletins 122, 152 and Circular 11, which can be had 

 free by application to the Agricultural Experiment Station at Ber- 

 keley. 



The Black Scale (Saissetia alecs'). 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 con- 

 ditions. 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 trouble- 

 some 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 



