INSECTS AND DISEASES. 91 



afternoon, and then washed off with pure 

 water the following morning. This insect 

 does not attack plants that are syringed with 

 water daily, and all plants grown under glass, 

 not in flower, should be sprayed regularly. 

 When a house that has been infested with 

 Red Spider can be emptied of the plants, it 

 is well to burn sulphur on charcoal embers ; 

 the fumes from the sulphur are fatal to 

 nearly all insect life, and a house can by this 

 means be soon freed from this insect; as 

 burning sulphur is also destructive to plant 

 life, this process can only be used in emptied 

 houses, unless only a slight quantity be used 

 at a time. 



ROSE HOPPER, OR THRIPS (Tettigonia Rosa, 

 of Harris). This is perhaps the most trouble- 

 some pest with which the rose is afflicted in 

 the open air. It is a small, yellowish-white 

 insect, about three-twentieths of an inch 

 long, with transparent wings. Like the Red 

 Spider, they prey upon the leaves, work- 

 ing on the under side ; they seem to go in 

 swarms and are very destructive to the plant, 

 soon causing the foliage to assume a sickly, 

 yellow appearance. As they jump and fly 

 from one place to another, their destruction 

 is less easy to accomplish than is the case 

 with other enemies. We have found syring- 



