INSECTS. 455 



The apple, pear, and cherry are especially infested with 

 them. They multiply with wonderful rapidity. It is said 

 that one individual in five generations might bo the pro- 

 genitor of six thousand millions. Were it not that they 

 are easily destroyed, they would present an obstacle almost 

 insuperable in the propagation and culture of trees. 



There are many ways of accomplishing their destruc- 

 tion. Our plan is to prepare a barrel of tobacco juice, 

 by steeping stems for several days until the juice is a 

 dark brown, like strong beer ; we then mix this with a 

 solution of soft-soap, or soapsuds. A pail is filled with 

 this, and the ends of the shoots where the insects are 

 assembled are brought down and dipped into the liquid. 

 One dip is enough. Such parts as cannot be dipped are 

 sprinkled liberally. It is applied to the heads of large 

 trees by means of a hand or garden syringe. It should 

 be done in the evening. The liquid may be so strong as 

 to injure the foliage, hence it will be well for persons 

 using it the first time to test it on one or two subjects 

 before applying it extensively. This application must be 

 repeated as often as any of the aphides make their appear- 

 ance. The dry weather of mid-summer is generally the 

 time most favorable for their appearance. The season of 

 1871 has been remarkable for the prevalence of this pest 

 all over the country, not merely on fruit but on forest 

 trees. It has been so in Europe also. 



The Woolly Aphis or American Blight. This is a 

 small insect, covered with a white woolly substance that 

 conceals its body. They infest the apple-tree in particu- 

 lar, both roots and branches, living upon the sap of the 

 bark, and producing small warts or granulations on it by 

 the punctures. They are more particularly troublesome 

 on old rough-barked trees, as they lodge in the crevices, 

 and are difficult to reach. The wind carries them from 

 one place to another by the light down in which they arc 

 enveloped, and thus they spread quickly from one end of 



