When buying Citrus, Acacia or Choisya, check carefully to make sure they are free of infestation. If plants do become infested, this can be a difficult insect to eradicate. On small plants, look for and remove the scales and their egg mounds before eggs hatch.
In many parts of the world, an Australian ladybird known as the vedalia ladybird, Rodolia cardinalis, has been released as a biological control for fluted scale. This ladybird is not commercially available in the UK but it has been found in some parts of London. It probably arrived accidentally, along with the scale insect, on imported plants.
- Only plants that are small enough to be sprayed can be treated
- Organic sprays, such as natural pyrethrum (e.g. Bug Clear Gun for Fruit & Veg, Ecofective Bug Killer), fatty acids (e.g. Solabiol Bug Free, Doff Greenfly & Blackfly Killer) or plant oils (e.g. Vitax Organic Pest & Disease Control, Bug Clear for Fruit and Veg) can give good control of scale insects. These pesticides have a very short persistence and so may require reapplication to keep scale insect nymphs in check. Plant oil and fatty acid products are less likely to affect larger insects such as ladybird adults. These organic insecticides are the only products that can be used on citrus plants where the fruits are going to be eaten
- Ornamental plants can be treated more persistent insecticides include the synthetic pyrethroids lambda-cyhalothrin (e.g. Westland Resolva Pest Killer), deltamethrin (e.g. Provanto Ultimate Fruit & Vegetable Bug Killer) and cypermethrin (e.g. Py Bug Killer)
- The systemic neonicotinoid insecticide acetamiprid (e.g. Bug Clear Ultra) is also available for use on ornametal plants
- 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 the RHS. It is a list of products currently available to the home gardener
Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)