208 



EXPERIMENTAL FARMS. 



ring upon the bark of the twigs or leaves and in large numbers, the scales lie close to 

 each other, frequently overlapping, and are at such times dilMcult to distinguish with- 

 out a magnifying glass. The general appearance which they present is of a gray- 

 ish, very slightly roughened scurfy deposit." (Fig. 12.) 



The natural rich reddish colour 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 yellow- 

 ish oily liquid will appear, resulting from the crush- 

 ing of the soft yellow insects beneath 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. During winter 

 the insect is to be found in the half grown, or near- 

 ly full grown condition. The young begin to hatch 

 and to crawl from under the female scales shortly 

 after the trees leaf out, and from this time through 

 the summer there is a constant succession of gener- 

 ations. The insect affects not only the young 

 twigs and limbs and, with young trees, the entire 

 plant, but is also found upon the leaves and upon 

 the fruit. When it is abundant, the fruit is destroyed. 

 One of the most characteristic points in the appear 

 ance of the insect upon fruit is the purple discoloration around the edge of each scale. 



Fig. 1 4 shows a pear attacked 

 by the scale and a separate 



The male 

 minute insect. 



Fig. 12.— San 

 with scales : 



Jose Scale : Apple branch 

 large scales above at left. 



figures will 

 ers to 

 should 

 enough 



recognize 



scale much enlarged 

 is an active 

 (Fig. 13). 



The above description and 

 enable fruit-grow- 

 this enemy 

 they be unfortunate 

 to get their orchards 

 infested with it. With regard 

 to remedies, we have the ad- 

 vantage of all the experience 

 of Californian experimenters, 

 the careful work of the Divis- 

 ion of Entomology at Wash- 

 ington, and of Prof. J. B. Smith, 

 of New Jersey, during the past 

 year. There are three methods 

 which have proved effective 

 in fighting the San Jose Scale. In cases of severe attack, it is recommended to 

 cut down the infested trees and burn them. The other methods are : Spraying with in- 

 secticidal washes or fumigating the trees with poisonous gasses. The insecticidal washes 

 may be divided into summer washes, which can be applied while the trees are in leaf, 

 and winter washes of a stronger nature which would injure the foliage, but will do no 

 harm to the trees during the winter when these are in a dormant condition, and yet 

 will have the effect of destroying the scale insect. Of the summer washes, the ordinary 

 Kerosene emulsion (Riley-Hubbard formula) and a Resin wash [Resin 20 lbs., caustic 

 soda (70 per cent strength) 5 lbs., fish oil 3 pints, water 100 gallons], were recom- 

 mended by Mr. Howard, and used with success during the past summer. On peach 

 trees, owing to the susceptibility of the foliage to injury, the stock emulsion was diluted 

 with fifteen times its volume of water, instead of nine times, the usual strength advised 



Fig. 13. — San Jose Scale : male adult, greatly enlarged. 



