INSECTS AND DISEASES. gt 
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 ( 7ettigonia Rose, 
of Harris).—Thisis perhaps the most trouble- 
some pest with which the rose is afflicted in 
the open air. It isa 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- 
