Management of Wheat dwarf virus (WDV) in cereals

Wheat dwarf virus (WDV) is spread by a relatively new leafhopper species in the UK. Find out about the pest species, virus symptoms and infection-risk management.

Wheat dwarf virus (WDV) can cause major yield losses in wheat and barley.

The disease has been problematic in mainland Europe for several decades, although it is often highly localised with large season-to-season variability.

The disease was first recorded in the UK in the early 2010s.

WDV is thought to be almost exclusively spread by a single leafhopper species: Psammotettix alienus.

This species was first recorded in the UK in 2014 (at sites in Cambridgeshire).

Psammotettix is a large genus of similar species, which makes them difficult to identify.

P. alienus may have been present in the UK for many years before it was first noted. Like other leafhoppers, P. alienus adults are small (about 2 to 3 mm long).

Adults of this species have elongated yellow-brown bodies.

Although the national distribution of P. alienus is not known, targeted crop sampling and laboratory testing confirmed the presence of WDV in more than 70 crops suspected of having the virus in spring 2026.

The testing was coordinated by members of the Association of Independent Crop Consultants (AICC).

This found WDV in winter barley and winter wheat crops across England: from Yorkshire to Berkshire (North to South) and Norfolk to Oxfordshire (East to West).

Most infected crops were in East Anglia.

WDV is caused by the virus Mastrevirus hordei.

The virus is taken up by the leafhopper’s salivary glands and can be passed on to plants rapidly (within a few minutes).

It does not replicate inside the insect.

The leafhopper is commonly found in open grassland and woodland glades.

Primary infection occurs when adults migrate into fields with newly emerging cereal plants in the autumn.

There are WDV strains with strong host preferences (either for wheat or barley). However, both strains can affect both crops and the virus has also been detected in other cereals (triticale and rye) and some grasses (including perennial rye-grass).

Leafhopper adults are killed by cold temperatures, especially sustained frosts (less than -5°C).

The species overwinters as eggs.

When temperatures warm, new nymphs and adults can cause secondary spread in the following year.

Cereals are likely to be very susceptible to WDV infections until stem elongation.

Typically, one to two generations are recorded in the UK, although up to four may occur.

There's no evidence that WDV is seedborne or mechanically transmitted.

Notes:

• Since 2013, Oat dwarf virus (ODV) has been classified as a distinct species (Mastrevirus avenae), and it isn't clear if oat also hosts WDV
• P. provincialis can also spread WDV, but this species has not been recorded in the UK

Cereal symptoms include:

• Poor rooting
• Dwarfing
• Bushy growth with multiple shoots
• Leaf yellowing (chlorosis)
• Yellow (in barley) or red (in wheat) discolouration
• Stunting or death of tillers
• Delayed ear emergence
• Plant death (in extreme infections)

Leafhoppers readily move between plants and spread the virus by primary infection.

As a result, symptoms are often relatively spread out in small, peppered patches across field.

This sets it apart from other key cereal viral diseases, which often form in relatively large, distinct patches, as seen in crops infected with Barley yellow dwarf virus (BYDV).

At the individual plant level, cereal viral diseases often look similar and can also be mistaken for symptoms of drought and nutrient deficiency.

Mixed infections (WDV and other viruses) may also be common.

Frost damage may also be greater in WDV-infected crops.

• Cereals sown after hot, dry summers (which promote leafhopper populations)
• Presence of green bridges that act as virus reservoirs*
• Early sown crops (young plants are exposed to the leafhoppers for longer while they are highly susceptible to infection)
• Warm autumns that promote longer feeding activity

*Cereal volunteers and some grasses act as reservoirs for the virus. However, the virus tends to be isolated at much lower rates in wild grasses, compared to BYDV.

Management is similar to the recommendations for controlling BYDV-spreading aphids.

• Avoid growing susceptible cereals in areas where the disease has been problematic in recent seasons

• Manage ‘green bridges’ that transfer leafhoppers/virus to new crops. For example, use cultivations to disrupt potentially infected plant material (e.g. volunteers/stubble) and leafhopper populations
• Grow resistant/tolerant varieties, when available (see notes)
• Drill crops as late as possible (until mid-October in high-risk areas)
• Minimise general stress to plants

There are no plant protection products authorised for the control of Psammotettix alienus in the UK.

Although pyrethroid sprays may control these leafhoppers, optimal spray timings are likely to differ to those used to target the second-generation aphids that spread BYDV.

The Recommended Lists for cereals and oilseeds (RL) includes information on resistance/tolerance to some viruses, including WDV.

Such characteristics are based on ‘breeders’ claims’ and are not verified in RL trials.

Accepted claims are usually associated with clear genetic markers that allow breeders to verify if a variety has inherited the trait.

In RL 2026/27, only one winter barley has this specialist trait for WDV (tolerance).

Partial resistance has been confirmed in some winter wheat varieties in mainland Europe.