Although paraffin in various forms is often recommended, let me urge upon my readers that it is a most dangerous substance to use upon the rose—a naturally delicate plant—as any remedy of a caustic nature is sure to do it far more harm than good.
Tobacco wash is recommended by the Continental rose-growers for Aphis, 1 part of tobacco-juice to 15 parts of water. If a little soft-soap is added it makes a better wash. This is also a good wash for
Cuckoo Spit or Frog-Fly.—This frothy substance if washed off will be found to contain a yellow creature, often closely wedged into the angle of leaf and shoot, or at the base of a flower bud. This is a "nymph" or young Frog-Fly—a most destructive insect—and unless removed it will so quickly suck the sap of the leaf and bud that it dies and falls off.
To get rid of them requires patience. We must either hand-pick the roses—or if we spray with the tobacco wash it is necessary to syringe the plant with plain water first, using some force, to wash off the white froth—and then spray with the tobacco wash to kill the "nymph."
This leads us to the more active and the worst of all the pests we have to fight against.
Beetles, Bees, Flies, and Moths,
which either in their adult form or as maggots and caterpillars prey upon the rose.
Four Beetles are among the enemies of the rose. The beautiful green Rose Beetle or Rose Chafer does harm in both stages. As a grub it feeds underground on the roots; and as a beetle eats the foliage and the petals and anthers of the flowers. I find it is particularly fond of the delicate blossoms of the Yellow Persian Briar.
The Cock Chafer also eats the foliage, and its large white grubs devour the roots of the roses to such an extent that they often kill the plant. As the grubs remain for three years in the ground the damage they can do is incalculable; and they attack other plants besides roses. Among the roots of a herbaceous Spiræa I lifted this last winter, I caught forty of these grubs, and found they had so honey-combed the roots that the plant had to be burnt.
The Summer Chafer and Garden Chafer also attack roses.