Pulvinaria hydrangeae scales affect a whole range of trees and shrubs and are often found on the underside of leaves. The whitish ovisac, up to 10 mm in length, is formed in the months of June to August and is elongated with three clear furrows. Often a female drops off after the eggs have been deposited, leaving only the ovisac on the leaf. 

Unless identified by a recognised expert, a photo is required. If the photo doesn't show the key ID features then in the comments box describe the size and identifying characters you have observed.

Various habitats as this scale insect uses a whole range of host plant species.

Look for females with white ovisacs from June to August.

Univoltine; hibernation as larva on the young branches.

True status in Britain is difficult to determine due to lack of records.

Status in Leicestershire and Rutland not known.