Scientific name: Trioza vitreoradiata
Plants affected: Pittosporum
Main symptoms: Pale bulges and distortion on leaves
Most active: April-September
What is pittosporum sucker?
Pittosporum sucker feeds on sap from foliage of pittosporums during the spring and summer, this can result in distorted discoloured leaves. The plant can tolerate this damage.
Adult pittosporum sucker are winged pale green insects, about 4mm in length, older individuals are a darker green. The nymphs are flattened and pale, almost white, and less mobile than the adults.
Damage by pittosporum sucker is unlikely to cause a serious lack of vigour in the plants although it can affect appearance. Therefore it can be tolerated.
Check pittosporums frequently from spring so action can be taken before a damaging infestation has developed. 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.
- Often suckers do not affect the growth or vigour of plants and so can be tolerated
- Encourage predators and other natural enemies of suckers, in the garden, such as birds, ladybirds, wasps and ground beetles.
- If necessary distorted leaves can be removed from the plant however, this may cause more damage than the insect
Pesticide controlThe RHS believes that avoiding pests, diseases and weeds by good practice in cultivation methods, cultivar selection, garden hygiene and encouraging or introducing natural enemies, should be the first line of control. If chemical controls are used, they should be used only in a minimal and highly targeted manner.
- 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. 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 suckers. These pesticides have a very short persistence and so may require reapplication to keep sucker 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 against aphids (e.g. Ecofective Bug Control, RHS Bug and Mildew Control, SB Plant Invigorator and Westland Resolva Natural Power Bug & Mildew). These products contain some synthetic ingredients and so 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)
- A systemic containing the active ingredient Flupyradifurone (Provanto Smart Bug Killer) is available for use on ornamentals and selected edibles
- 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 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.
Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)
Originating from New Zealand, pittosporum sucker became established in south west England in 1993 and is has now spread throughout southern England, is established in parts of Scotland and also occurs in Ireland.
The whitish green nymphs are extremely flat and, almost scale-like in appearance. The yellowish green adult insects have two pairs of wings which are held in a roof-like fashion over the insect’s abdomen when at rest and are usually 3-4mm long. There are several generations during the summer with most damage occurring when new growth is developing.
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