Control
There are no easy control measures for rhododendron leafhopper. However, flower buds infected with bud blast can be picked off and disposed of to reduce the amount of fungal spores being released in the vicinity of the plants. This may only be feasible on smaller plants.
When choosing control options you can minimise harm to non-target animals by starting with the methods in the non-pesticide control section. If this is not sufficient to reduce the damage to acceptable levels then you may choose to use pesticides. Within this group the 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.
Non-pesticide control
- Rhododendron leafhopper does not affect the growth or vigour of plants and so can be tolerated
- Flower buds infected with bud blast can be picked off and disposed of to reduce the amount of fungal spores being released in the vicinity
- Encourage predators and other natural enemies of suckers, in the garden, such as birds, ladybirds, wasps and ground beetles.
Pesticide control
- There are no effective fungicides for bud blast
- Organic sprays, such as natural pyrethrum (e.g. Bug Clear Gun for Fruit & Veg, Neudorff Bug Free Bug and Larvae Killer), fatty acids (e.g. Solabiol Bug Free, Doff Greenfly & Blackfly Killer) or plant oils (e.g. Vitax Plant Guard Pest & Disease Control, Bug Clear for Fruit and Veg) can give good control of leafhopper. These pesticides have a very short persistence and so may require reapplication to keep leafhopper numbers in check. Plant oil and fatty acid products are less likely to affect larger insects such as ladybird adults
- Plant invigorators combine nutrients to stimulate plant growth with surfactants or fatty acids that have a physical mode of action (e.g. Ecofective Bug Control, RHS Bug and Mildew Control, SB Plant Invigorator and Westland Resolva Natural Power Bug & Mildew). These are not considered organic
- More persistent contact-action 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
- Several applications may be needed during late summer-autumn to deal with adult leafhoppers flying in from nearby gardens or from Rhododendron ponticum growing in woods
Follow label instructions when using pesticides.
Plants in flower should not be sprayed due to the danger to bees and other 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.
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Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)