OP THE FARM AND GARDEN. 265 



discolor the opening buds. Dusting freely with White 

 Hellebore has also been tried with very good success, and 

 it may be used in water, as directed for Currant worms, 

 p. 304. The Pyrethrum powders have as yet been used 

 only to a limited extent, but with the prospect that 

 throughly applied they would prove efEectual. 



PLANT-LICE— APHIDES. 



There are a great many species of plant-lice or aphides. 

 Almost every plant is liable to the attacks of some species 

 peculiar to itself. They are found upon the roots as 

 well as upon the stems and leaves, where they insert their 

 long tubular beaks and suck the juices of the plants, and 

 only change their places when they have exhausted the 

 sap in that locality. It would be impossible to even men- 

 tion the various species in a work like this, much less to 

 give a detailed descrij)tion of them. Every farmer and 

 gardener will know from the curled appearance of the 

 leaves of various trees and herbaceous plants the author 

 of the mischief. 



Numerous parasites keep these destructive plant-lice 

 greatly in check, and it is always well to look closely, be- 

 fore making an application to destroy the lice, to see if 

 there are not some parasites at work, and if so they will 

 often clear the plants much more effectively than any 

 remedy we can apply. This I have observed both at the 

 North and South, and usually when I have been studying 

 other insects. 



In Florida I was studying a large black and red ant 

 {Campanotus esuriens), and was greatly interested in 

 their immense droves of dark-colored aphides — the " ant's 

 cows" as they are often called, that were thickly clustered 

 on the underside of the young leaves of an orange tree. 

 "While watching the ants moving about among the droves, 

 I noticed several tiny Ichneumon flies mounting the 

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