Cypress aphid Of Leyland Cypress

Disease Information

Cypress aphid

Cypress aphid is one of the causes of dieback on conifer hedges. It has become an increasingly damaging pest on conifer hedges since the 1980s, particularly on Leyland cypress.



a)      Yellowing shoots in summer; by late summer many of these will be brown and dead.

b)      On clipped hedges the dieback can be quite pronounced, with the lower parts more severely affected than the top.

c)      A black powdery coating of sooty mould may develop on the stems and foliage.

d)      Damaged hedges can recover but it is likely to be a slow process.


Chemical control

1)      Spray in early summer to prevent damage occurring .

2)      Suitable products contain thiacloprid (e.g. Bayer Provado Ultimate Bug Killer Concentrate) or acetamiprid (e.g. Bug Clear Ultra) .

3)      It is often difficult to spray large dense hedges thoroughly, and in years when the aphid is abundant, some damage will occur .



Share this article