168 AN INTROD 



ami the ground to S>nu- >th> 



planted in the same place, but not an apple, 

 hould betaken in putting nut trees from a nur>. : 

 that thi "Hi this pest. If there is any doubt, the t: 



;!d be wa-hed, roots and all. in a strong solution of It is 



. to put in the fork of the trees a piece of hard soap, which 

 will be . 1 and washed down by the rains. This will sen 



,-nt certain other pests as well .is the woolly aphis from getting 



!d. In case it is desired to rid an inferred tree of this ] 

 the trunk form should be washed off with a strong .solution 

 applied with a sponge, taking care to destroy all and the 



:ul should be treated with carbon bisulphide, as i'or the grape 

 Phylloxera. 



Sub-Family IV. Arm DIN 



The sub-family Aphidinaj includes those genera in which the third 

 >idal vein of the front wings is twice forked ; the hind wings have 

 discoidal veins; and the honey-tubes are usually well develn: 

 times tuberculiform or obsolete. The number of species belong- 

 ing to this group is very great ; it being the largest of the sub-families 

 of the Aphididaj. Most of the species live above ground, on the 

 surface of leaves or twigs of woody plants or upon the 

 and .stems of the more succulent species. I do not know of any 



that produce galls. 



/.tic/inus. The largest of our species of Aphididae belong to the 

 genus iMiJinns. L. ciirvic is found on the pig-nut 

 hickory, clustered on the under side of the limbs 

 in summer; it is interesting from being perhaps 

 our largest plant-louse, measuring to the tip of the 

 138. Lacknus. abdomen 6 m m. ( 0.24 inch , and more than 10 mm. 

 ; inch) to the tip of the wings. 



Aphis. To the /////.v, in its i : sense, ; con- 



siderable number of the important species of this sub-family. The 

 that occurs in such immense- numbers on cabbage is Aphis 

 brassicn-. It is the most common, and, perhaps, the most injurious 

 that occurs in the vegetable gardens of this country. The 

 i riant-louse is Aphis wait/is. This Speci< ding to the 



rvations of Forbes, winters in the wing! inic form in the 



!y infected. In the spring it appear^ to be 



Strictly dependent upon a sj> ant. /.(isiiis a/it'ims, which mines 



along the principal roots of the corn, collects the plant-lice, and 



