Flower stalks of plants with severe infections often dry up without producing flowers. Since the fungus is probably present in the bulb, infections occur as flower stalks and leaves emerge from the bulb. Control can be achieved by minimizing moisture on the leaves and flower stalks by careful watering. It is also helpful to provide good ventilation and plenty of light since these will decrease the chance of spreading the fungus. Heavily infected bulbs should probably be discarded.
Foliage appears mottled and can develop white or pale yellow spots which often turn red.
Additional symptoms include stunting of the flowers and death of leaves. Since these are systemic diseases, destruction or roguing of infected, symptomatic plants helps to prevent spread of the viruses to healthy ones. Once a plant is infected, recovery is unlikely although symptom severity and expression may wax and wane with changes in season. Insect Problems Potato aphid, Macrosiphum euphorbiae. The potato aphid, Macrosiphum euphorbiae , normally passes the winter as glossy oval black eggs on roses.