Aphids on delphiniums outdoors can be controlled using malathion sprays or imidacloprid can be applied as a soil drench for season-long, systemic control. Consult the labels for dosage rates and safety precautions. Leaves and flowers are badly deformed, leaves are brittle and thickened with black or brown spots or streaks. This trouble is caused by cyclamen mites. The cyclamen mite, Phytonemus pallidus , is a translucent, microscopic mite that often infests the new leaf and blossom buds, and can proliferate on spent blossoms.
Characteristic injury includes dwarfed, thickened and wrinkled leaves.
On azalea, dahlia, and other plants with stems, the distance between internodes becomes drastically shortened. Infested plants do not bloom, or blossoms may be misshapen. Effective restricted use products are abamectin, dicofol, and endosulfan. Cutworms , Feltia subgothica . New transplants are often cut off at ground level by this worm.