The march moth is a medium-sized moth that's closely associated with woodland, heathland and scrub habitats but can be seen in the garden too. This species is sometimes called a winter moth because of its flight period tends to be during the colder periods of the year. Mature moths are on the wing during March through to April. The caterpillars are considered pests of trees, with the most common food plants being hawthorn (Crataegus), oak (Quercus) and fruit trees.
These moths are an excellent food resource for birds, bats and hedgehogs.
Can defoliate trees when in large numbers.
These are a variable species. The wings can differ between individuals, but generally, male moths are a mottled light or dark brown with a wingspan reaching 3.5cm total. They fold their wings by crossing them over each other, which is fairly unique for a moth. Females are wingless, often seen on tree bark which is where they lay their eggs. They're plump and a mottled light brown. The caterpillars are pale green. They possess faded longitudinal stripes as well as having pale-yellow stipes between segments. They feed on oak, hawthorn, and other various fruit trees.
Caterpillars may be seen oak, birch, hazel, hawthorn, blackthorn, apple, dog-rose, hornbeam and elm. These caterpillars will eat leaves of food plants leaving holes missing from the leaves. Blossom and developing fruit can be damaged from caterpillar feeding behaviour. Caterpillar feeding can sometimes cause formation of clefts in developing fruits.
These moths are widespread across Europe.
It's thought that these caterpillars can be tolerated on non-fruiting trees. This is because they won't cause any long-lasting damage and overall health remains unaffected. These caterpillars provide a reliable source for bats, birds and hedgehogs. By placing sticky grease bands or glue barriers at the bottom of tree trunks, you can stop females climbing trees to lay their eggs. This must be done before October through to April.
Unfortunately, there's not much to be done in terms of treating trees chemically. Trees can be large, and it's generally impossible to cover the whole surface area. Sometimes it's best to let nature take its course and leave the pests to their numerous natural enemies. Ultimately, using chemical control will remove these from the environment, but this may exacerbate the problem in the long term, it's better to aim for a balanced ecosystem with a diverse range of plant and animal life. Trees are resilient, they will recover the following year in most cases, the chances of survival increase with tree age and size.