Pulvinaria hydrangeae

Hydrangea scale

Description

This invasive species was introduced into Europe in the 1960s. More frequent in southern parts of Europe. It first spread on ornamentals but has been occurring also on broadleaf forest trees. The scale feeds on the lower side of the leaves. The tiny, yellowish to pale green larvae are often hardly visible, but the typical white wax cover from the mother scale can be as much as 8 mm in length. On the upper side of the leaves, honeydew and black layers of sooty mould can often be found. Leaves that are strongly sucked start to wilt in August and may be shed prematurely. There have been no reports of real damage or growth loss in forests. The scale overwinters as larvae on twigs. In May parthenogentic reproduction starts and the insects crawl to the new leaves. Several relative species as for example P. floccifera and P. regalis are found in Europe.

Symptom

The tiny, yellowish to pale green larvae are often hardly visible, but the typical white wax cover from the mother scale can be as much as 8 mm in length. Wax coatings are clearly visible from a distance.

Tree Species: Cherry, Maple, Lime, Rhododendron

Part of a plant- attacked: Leaf / Needle

Pest significance: Harmful

Pest Category: Insects

Invasive Species: Yes

Present in EU: Yes