Control
Whilst the appearance of this insect can be alarming and almost all of the foliage can become covered in webbing and turn brown, the plants usually recover without treatment and so control is not necessary. Additionally, these moths do not usually occur in high numbers year on year, so are unlikely to be a persistent problem.
Non-pesticide control
- Inspect plants for signs of webbing and damage in late spring and late summer. If the caterpillars are confined to a few shoots, these can be pruned out
- Encourage predators and other natural enemies in the garden such as birds
Pesticide control
If populations are too big to be tolerated or pruned out, control may be achieved by spraying with pesticides. Shorter persistence pesticides (that are usually certified for organic growing) are likely to be less damaging to non-target wildlife than those with longer persistence and/or systemic action.
- Thorough and forceful spray coverage is required to penetrate silk webbing
- Organic contact insecticides containing natural pyrethrins (e.g. Bug Clear Gun for Fruit & Veg, Neudorff Bug Free Bug and Larvae Killer). Several applications of these short persistence products may be necessary to give good control
- More persistent contact insecticides include the synthetic pyrethroids lambda-cyhalothrin (e.g. Westland Resolva Bug Killer), deltamethrin (e.g. Provanto Ultimate Fruit & Vegetable Bug Killer, Provanto Sprayday Greenfly Killer) and cypermethrin (e.g. Py Bug Killer)
- The systemic neonicotinoid insecticide acetamiprid (e.g. Bug Clear Ultra) is also available
Follow label instructions when using pesticides.
Plants in flower should not be sprayed due to the danger to pollinating insects.
Inclusion of a pesticide product does not indicate a recommendation or endorsement by RHS Gardening Advice. It is a list of products currently available to the home gardener.
Downloads
Pesticides for gardeners (link downloads pdf document outlining pesticides available to gardeners).