136 The Amateur's Book of the Dahlia 



the juice into their bodies. Every now and 

 then they raise their hind legs and discharge a 

 sweet syrup of which ants are very fond. Ant 

 hills are always found near a colony of aphids. 

 Late in the summer the last generation of fe- 

 males develop wings once more, and fly back to 

 the fruit tree whence their ancestors came. 

 Then comes a generation exclusively of hus- 

 bands and fathers who shortly perish, leaving the 

 women folks to hibernate and begin operations 

 next spring. 



We cannot afford to leave the work of de- 

 struction of aphids entirely to the birds and 

 lady bugs. A mild solution of nicotine-sulphate 

 is a good remedy. (Black Leaf 40 added 

 to whale oil soap solution is as effective as 

 any.) Usually a solution a little more 

 than half the strength of that used on roses 

 suffices to kill the lice on dahlias. The tender, 

 soft growth cannot stand the irritation caused 

 by tobacco when very strong. The three aphids 

 vary in their habits only a little, but the treat- 

 ment is about the same. In the case of young 

 plants, if only a few shoots are slightly affected, 

 the aphids can be wiped off or the shoots cut off 

 and burned. 



White flies appear late in June or early July, 

 when hot weather first begins, and can be 



