Remedies.

No remedy for aphis blight in any way effective was discovered until about 35 years ago, when washing the plants was adopted page 12 to disturb the insects and to cleanse the leaves. Water alone was used, without much effect. Then soft soap was used with the water, and sometimes a little tobacco juice was added. This mixture is fairly efficacious if applied properly and often enough, but the best mixture is water, soft soap, and quassia. Quassia and water will not answer without soft soap, as the aphides have the power of resisting liquid without soap. It simply runs off and over their bodies, as water runs off and over the backs of water fowls. When soap is mixed with water and quassia the detergent nature of the soap neutralises their oily secretion and exposes them to the action of the liquid, and fixes the bitter of the quassia on the leaves, making them unpalatable. The soft soap also acts as a lubricator of the pumps of the machines employed for washing the plants.

This wash is sent up, squirted up and over the hop plants-the play of the jet being directed to the under surfaces of the leaves-by means of large garden engines with strong pumps and long flexible hose, and jets held under the leaves by men. Large planters employ washing machines^* drawn by horses between the rows, whose pumps are worked by the wheels and force the wash up and over the plants through a series of tubes perforated at intervals.

This washing process in order to be perfectly successful must be commenced directly there is any deposit of lice upon the leaves, and continued systematically until all of these have been cleared off. In some seasons fresh flies are continually wafted to the plants, and in this case it will be necessary to wash frequently and watch the plants with great care.

The advantages of washing hop plants for aphis blight were clearly shown in 1882. Planters who washed grew crops of from 7 to 9 cwts. per acre, while those who did not wash then plants grew nothing or next to nothing.

In connexion with remedies against aphides it should be pointed out that the chief natural enemies of the hop aphides are the little spotted beetles commonly called ladybirds, Coccinellœ, and that these should be religiously preserved in all hop districts. They have been known to avert an impending blight, coming in countless quantities and devouring the aphides as fast as they were generated. In America insects and animals that

^* The horse washing machines have recently been much improved.

page 13 destroy insects injurious to crops are encouraged and protected. Among one of the remedies for the attacks of insects given by the entomologist of the State of New York is "Colonising" lady bugs, the Coccinellidæ, upon house plants and other "vegetation infested with plant lice."^*