If you’ve been out and about in the countryside recently, you may have seen mysterious white webbing covering trees and shrubs in the area.

Looking like a scene from Aragog the spider’s lair in Harry Potter, or from inside Miss Havisham’s abandoned wedding reception in Great expectations, trees are covered from head to toe in a thick white coating.

Mick Holland spotted this scene near Ludgershall, and while it may look dramatic, it’s nothing to be alarmed about – it’s just silk webbing spun by ermine moth caterpillars as they feed and grow.

There are many different kinds of ermine moths, with their name referring to the vast white webs they can create when living together. They are found particularly in areas where plants grow in chalk or limestone-based soils, such as north west Hampshire and Wiltshire.

The moths fly at night between June and September in a single generation, where they mate and lay their eggs. It is the caterpillars, rather than the moths, that produce the silk.

The webs are made to help protect the caterpillars from predators and parasites, and the thick webbing also helps prevent any competition for the leaves they feed on.

While the webbing may look dramatic, it isn’t a risk to human or animal health, though the presence of the caterpillars eating away at the tree means that most of the leaves may be eaten by the time the caterpillars have become full-grown moths.

That said, the RHS says that these webs “should not affect the long term health or vigour of host plants”, and that the moths generally target different trees each year, so that any plant covered in silk is unlikely to be killed by the caterpillars.

In addition to trees, whole hedges can sometimes be affected, leading to striking pictures as they go about their work.

The webs will be around for another month or so before all the caterpillars metamorphose into moths, before returning again next year.