Dotted Moth: Webs in Apple Trees, Hawthorns, or Spindle Trees

Spotted Moth or Webworm in an Apple Tree (also found on spindle trees, hawthorns, pear trees, or cherry trees)

It's happening again this year: There are large, tough webs in the apple tree. If you look closely, these webs are completely filled with caterpillars, which are slowly eating the leaves off the apple tree.

Spotted moths (also known as web moths) create distinctive webs that are easy to recognize. They can even completely envelop entire trees and shrubs with their webs. Fortunately, it usually stops at just a few branches or parts of the tree. The web protects the speckled moth from natural predators, such as birds. Depending on the species, the caterpillars are white, yellow, or gray, with black spots.

Which trees and plants are affected by the leaf miner moth?

There are many different species of dot moths (Hyponomeuta). Each species has its own preference for a particular tree or plant. For example, there is the apple dot moth, the spindle tree dot moth, the hawthorn dot moth, the wild cherry dot moth, and the willow dot moth; ornamental cherries, pears, plums, and blackthorns are also among their favorites.

Webworm / Spotted Moth caterpillars in the tree

Can the webworm or the spotted moth harm a tree or shrub?

In most cases, trees can withstand an infestation of these caterpillars just fine. Since there is still plenty of the growing season left once the caterpillars are gone, the tree or shrub will produce plenty of new leaves and shoots again this year.

How can you control and prevent the dot moth or web moth?

You can prune away the affected branches to prevent the disease from spreading further in your tree or shrub. If you spot and remove the webs early on, the infestation usually won’t spread much further. If you leave the affected parts alone, however, the infestation may spread rapidly. Even then, though, the tree won’t suffer immediate, permanent damage. Therefore, removal isn’t really necessary.

We definitely do not recommend using (chemical) pesticides for this purpose. This does more harm than good. In fact, it is also very harmful to beneficial insects and birds!

The best way to keep an infestation of these caterpillars under control is to have plenty of birds in the garden. Titmice, in particular, are nimble enough to pierce the web and pick out the caterpillars.