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Page:Popular Science Monthly Volume 44.djvu/226

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THE POPULAR SCIENCE MONTHLY.

it is literally true that the odor of the various preparations used to destroy insect life is universal for miles and for days at a time. Nine tenths of the discussions in the innumerable local clubs of fruit-growers that are doing so much for the practical advance of the industry in California are discussions upon methods PSM V44 D226 Almond bough in july.jpgAlmond Bough in July. for the destruction of these pests. Sometimes one sees hundreds of acres of orchard, in February, snow-white over every inch of twig, with "salt and lime wash," or other acres are brown with sulphite of soda or oil and alkali. Now and then comes an orchard where the remedies have been used in too great strength, and the buds and tender bark seem blighted and blackened.

The prevailing enemy of the orchards is the insect family Coccidæ. The species that do most harm are the oyster-shell scale (Mytilaspis pomorum), the pernicious scale (Aspidiotus perniciosus), the yellow orange scale (Aspidiotus citrinus), the red orange scale (Aonidia aurantii), and the apricot scale (Lecanium armeniacum). The Florida red scale (Aspidiotus ficus) and the mining scale (Chionaspis biclavis), a very dangerous species from Tahiti, are being quarantined against by the horticultural commissioners. A cargo of 325,000 orange trees infested with the Tahiti species was once destroyed by Mr. Craw, the quarantine officer of the State Board. Another group of scale insects known as "cottony scales" (Icerya and Dactylopius) are among the worst enemies of the orchardist. Aphides, canker worms, caterpillars, and fungoid diseases are as yet of much less immediate danger to the fruit-growers than the various Coccidæ of which I have named only the prominent species.

Many valuable formulas for summer and winter washes, for kerosene emulsions, and other preparations were first used in California. The hydrocyanic-acid-gas method is also a Californian