Prevention.

One of the best modes of prevention in the case of aphides is undoubtedly to put caustic substances, as lime, soot, lime ashes and others, round the stocks, or plant-centres, during the winter. Bines should be carefully collected and removed from the hop gardens before February. All dead pieces of bine should be cut away from the stocks and burnt or taken away. The outsides of the hop gardens should be kept brushed, and weed growth prevented. If damson trees near are infested with aphides-not the ordinary plum aphis (Aphis pruni), which is distinct from the hop aphis, but the Mahaleb variety, which so closely resembles it-they should be washed with soft soap and water, to prevent the migration of flies to the hop plants.