60 
nozzle throwing a strong stream hj pumping the liquid back upon 
itself. When properly combined the mixture will have become of the 
consistency of thick cream. It is then placed in moderately tight 
receptacles, and will keep almost indefinitely until required for spray- 
ing, when it is to be diluted. For plant-lice this staple_ emulsion is 
usuall}^ diluted with from 10 to 15 or 20 parts of water. 
Its habit of feeding on the lower surfaces of leaves renders the 
melon louse more difficult to reach by means of a spray than insects 
which live on the upper surfaces. In the application of an emulsion 
or other wash, therefore, it is necessary that the hose be fitted with an 
upturned nozzle in order to secure the under spraying of the leaves, 
which is the principal resort of plant- lice and many other sucking 
insects. 
It is of the utmost importance that the sprays or other remedies 
be applied on the first appearance of the insect in order to check it 
before it succeeds in obtaining a good start and to prevent its further 
development. 
Spraying ivith water. — A strong stream of water from a hose 
directed on plants, so as to hit the insects, is of much value in dislodg- 
ing them from the plants, to which they do not usually succeed in 
returning, and where this can be readily done more elaborate reme- 
dies are unnecessary. 
Pyrethriim, administered with a powder bellows to the lower sides of 
leaves is also valuable and particularly^ effective on young plants. It 
is, however, expensive, and can not be profitably used in large fields. 
Olean culture and fall plowing should be followed as the most effect- 
ive measure of prevention of attack by plant-lice as well as other 
insects, and this includes the keeping down of weeds after the main 
crop has been gathered until the next crop is planted, this treatment 
serving to rid the fields of many pests, particularly those which do 
not fly readil3\ by depriving them of food. 
Fumigation metJiods. — In yqtj recent years two methods of fumiga- 
tion have been rather extensively practiced as a means of destroying 
the melon louse and related insects on valuable plants. It is doubtful, 
however, if either of these remedies would be necessary on beets 
except in regions where injury is more extensive than has thus far 
been reported. 
If careful watch is kept for the first appearance of this plant louse 
it can be more thoroughh^ eradicated by means of fumigation than by 
any other method. The method of application of bisulphid of carbon 
consists in covering the affected plants on the first appearance of the 
pest with a tub or similar receptacle, and evaporating the chemical 
beneath this at the rate of a dram to 1 cubic foot or less of space 
