Plant Health Problems
Once established, weigela generally is disease-free.
Fourlined plant bug, Poecilocapsus lineatus.
The bugs often injure the tender terminal leaves of weigela. This bug lays eggs in the soft stems. They hatch about the middle of May and the young bugs suck the sap from the tender leaves. They molt five times and when mature, about the middle of June, they have wings and are nearly 1/3" long. The insect body is yellow, marked lengthwise on the wings with four black stripes alternating with three green stripes. The injury to the leaves consists of sunken areas around the punctures. These areas later appear as circular transparent spots and finally as circular holes. This insect injures the new leaves of many different kinds of annual and perennial plants and shrubs. There is one generation each year. The nymphs can be managed by spraying with ultrafine horticultural oil, insecticidal soap or malathion, which are among the compounds registered for control of this pest in Connecticut. Imidacloprid, applied as a soil drench, will provide season-long systemic control. Consult the labels for dosage rates and safety precautions.