Raspberry leaf and bud mite

Yellow blotches on the foliage of raspberries are likely to be caused by a tiny sap-sucking mite that lives on the underside of the leaves. Despite the appearance of plants with this mite they are often still able to produce a worthwhile crop of fruit.

Raspberry leaf and bud mite

Raspberry leaf and bud mite

Quick facts

Common name Raspberry leaf and bud mite
Latin name Phyllocoptes gracilis
Plants affected Raspberry
Main symptoms Pale yellow blotches on upper leaf surface. Some leaf distortion on upper parts of the canes
Caused by A microscopic mite that sucks sap on the underside of the leaves
Timing Late May-September

What is raspberry leaf and bud mite?

Raspberry leaf and bud mite is a microscopic mite that causes yellow blotches on raspberry leaves. It can sometimes be mistaken for a virus infection.

Symptoms

Raspberries with leaf and but mite show a number of symptoms;

  • From May onwards, pale yellow blotches develop on the upper leaf surface
  • On the corresponding places on the underside of leaves, the colour is slightly darker than the usual whitish green
  • Affected canes grow to their usual height and produce fruit but leaves at the tops of the canes may be malformed

Note: Some virus infections also cause yellow markings on the foliage, usually accompanied with stunting of the canes and poor fruit production. The mite is a more common problem than virus infections.

Control

Non-pesticide control

  • Raspberry leaf and bud mite can often be tolerated as it does not always affect cropping
  • Heavily infested plants that no longer produce a worthwhile crop should be replaced
  • Some raspberry cultivars are less susceptible to the mite. Observations on plants grown at Wisley indicate that these include ‘Glen Lyon’, ‘Glen Rosa’, ‘Glen Prosen’, ‘Glen Magna’, ‘Malahat’, ‘Gala’, ‘Tulameen’, ‘Julia’, ‘Rossana’, ‘Leo’, ‘Galante’, ‘Terrie Louise’ and ‘Lauren’
  • More susceptible cultivars include ‘Glen Ample’, ‘Glen Shee’, ‘Malling Jewel’ and ‘Malling Enterprise’

Pesticide control

None of the pesticides available to home gardeners will control this mite.

Biology

The microscopic mites overwinter in and around the buds on raspberry canes.

They emerge in late spring and begin feeding by sucking sap from the underside of leaves. This results in yellow blotches developing on the upper surface and slightly darker patches on the lower leaf surface where the mites are active.

The mite population increases during the summer and leaves at the shoot tops may fail to expand to their usual size and shape in heavy infestations.


Gardeners' calendar

Advice from the RHS

Find out what to do this month with our gardeners' calendar

Advice from the RHS

Did you find the advice you needed?

RHS members can get exclusive individual advice from the RHS Gardening Advice team.

Join the RHS now

Get involved

We're a UK charity established to share the best in gardening. We want to enrich everyone's life through plants, and make the UK a greener and more beautiful place.