134 The Amateur's Book of the Dahlia 



strength for sprays. The corpse of the borer 

 seems to act as a fertilizer! 



Be sure to give abundant water to the roots of 

 the plant for a day or two, if it is not cut back, 

 in order that it may more easily recover. If 

 much does have to be cut away, the plant puts 

 out new shoots with great speed. 



The six-legged enemies are divided into two 

 classes — those which suck the juice, and those 

 which chew. The insecticides employed against 

 the latter are to poison the leaf which they chew, 

 the poison being taken into their systems with 

 their food and killing them. Arsenate of lead 

 is the best for this purpose as, although it spots 

 the foliage by reason of its own whitish colour, 

 it does not injure them. The sucking insects 

 are not so easy to handle, especially on dahlias. 

 They must be killed by a chemical which pene- 

 trates through their skins. Any irritant which 

 is strong will kill the dahlia as well as the insects. 



Among the six-legged enemies are the aphids; 

 green, black, and white fly, who begin early in the 

 summer, as soon as the plants put out their 

 tender shoots, and continue their depredations 

 until frost. They may be grouped under the one 

 name, plant lice, and Huxley, whose word has 

 never been questioned, stated that the un- 

 interrupted breeding of ten generations from a 



