The leafhoppers are a family (Cicadellidae) of

Sap is a fluid that circulates through a plant's vascular system, in a similar way to blood moving through our veins. Phloem sap carries the sugars produced in the leaves by photosynthesis down to roots and other storage organs, as well as carrying minerals and hormones. Xylem sap is watery and transports nutrients absorbed by the roots upwards to the rest of the plant. Some plants leak sap from wounds or pruning cuts, and this is known as bleeding.

• A coarse pale mottling appears on the upper leaf surface of a wide range of plants in greenhouses, on houseplants and in gardens (similar mottling on sage, rosemary and other herbs is likely to be due to the sage or Ligurian leafhoppers)
• The spots can join together, giving the leaves a chlorotic appearance that could be mistaken for a mineral deficiency
• Damaged leaves will remain discoloured 
• Adult glasshouse leafhoppers are 3mm (about 1/8in) long and pale yellow with grey markings. They are broadest at the head end and taper to a point behind
• Adults jump off leaves and fly short distances when disturbed
• The creamy white, wingless nymphs are less active and can be easier to spot
• White cast skins shed by the immature nymphs can often be found attached to the underside of damaged leaves (aphid skins are usualy found on the top surface of leaves)

Check susceptible plants frequently from spring onwards so action can be taken before a damaging population has developed. When choosing control options you can minimise harm to non-target animals by using the methods in the non-pesticide section below. Pesticide treatments are likely to kill natural enemies and are only likely to be successful if the entire plant can be reached. 

Non-pesticide

• Often leafhoppers do not affect the growth or vigour of plants and so can be tolerated, they are part of the biodiversity a healthy garden can support
• Encourage predators and other natural enemies of leafhoppers, in the garden, such as birds, ladybirds, wasps and ground beetles

Pesticides

• Organic sprays, such as natural pyrethrum (e.g. Bug Clear Ultra 2, Neudorff Bug Free Bug and Larvae Killer) or plant oils (e.g. Vitax Plant Guard Pest & Disease Control, Bug Clear Fruit & Veg, Vitax Rose Guard) have a largely physical mode of action. These are broad spectrum so will kill a wide range of insects. 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
• Plant invigorators combine nutrients to stimulate plant growth with surfactants or fatty acids that have a physical mode of action against leafhopper (e.g. Ecofective Bug Control, Growing Success Bug Stop, RoseClear 3 in 1 Action and SB Plant Invigorator). These products contain some synthetic ingredients and so are not considered organic
• Further information about the use of pesticides available for management of leafhoppers is available on the pesticides for gardeners leaflet

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Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)

• Leaf mottling can be caused by the feeding activities of the adults and nymphs, which live mainly on the lower leaf surface
• This leafhopper has several generations during the growing season and can remain active throughout the year on indoor plants
• Eggs are laid in the leaf veins and hatch into wingless creamy white nymphs
• The nymphs shed their outer skin five times as they grow and finally become adults
• In midsummer, the life cycle can be completed in six weeks but takes several months in the winter