LIST OF INJURIOUS INSECTS 155 



grape. Then turning to number 26 in that list, the symbols 

 E;2 after the name Leafhopper will tell you that it feeds on 

 herbage, and that it is normally treated with a contact 

 insecticide. 



Now, supposing you are raising potatoes and find that a 

 hornworm is eating their leaves: in the tomato-potato 

 group of the following list you will find sixteen leaf-eating 

 insects, belonging to several orders. Referring to the insect 

 list on page 152 you will find that five of them belong to the 

 order Lepidoptera, and that one of them is a hornworm 

 and that a food poison may be used to control it. 



