Hawthorn Webber Moth
Scythropia crataegella
Hawthorn Webber Moth, Hawthorn moth
Scythropia.crataegella.mounted
by Sarefo. CC-BY-SA-3.0
Scythropia crataegella, or more commonly the Hawthorn Webber Moth, are concentrated towards southern parts of the country. The presence of these pests is best detected from the extensive sheets of silken spun webs they leave in hawthorn. The larvae of this species will also mine the leaves of hawthorn. They are most likely to be present in woodland, scrub, gardens, heathland and grassland habitats. These moths can also be found on blackthorn and Cotoneaster.
Traits

Larvae spin extensive webbing over the foliage of host plants. The leaves can turn brown and fall prematurely.

Damage is not long-lasting, with most plants recovering without any need for treatment.
Appearance
Adult moths are small with a wingspan only reaching 1.5cm. Their wings are mainly white, however, have variable light-brown markings. The markings generally comprise 2 thick brown bands that cross the white wing-scales. There is also lots of irregular brown dotting.
Larvae appear like small black caterpillars (1.5cm) which overwinter as young larvae. However, these begin leaf miners so are difficult to detect at this stage. Once fully grown, larvae break from leaf mines and spin dense webbing that can span a whole branch of a tree. Within the communally spun webs, they continue to feed on foliage until they pupate, spinning silk cocoons.
There are other species of moth that spin similar webs to the hawthorn moth, however, these do not infest cotoneaster. If you have webs of similar description in your garden, you may want to take a look at our records for the box tree moth, browntail moth and the ermine moths.
Symptoms
Extensive, white sheets of silken spun webbing that covers whole branches of hawthorn and Cotoneaster.
Activity
Crepuscular
Personality
Order
Lepidoptera
Family
Plutellidae
Metamorphosis
Complete
Distribution
Europe.
Biological treatment
Keep an eye on plants throughout the year. If the webbing is restricted to new growth it can be pruned out.
Chemical treatment
There are both organic and more persistent chemicals available on the market. It's advised to attempt all biological and organic treatments before moving on to persistent chemicals.
Please read label bottles thoroughly and avoid spraying during flowering periods. Many chemical treatments are non-specific, so can indirectly harm other wildlife.
Treatments must be applied thoroughly to penetrate the dense webbing.