Conifer Aphid (Cypress Aphid)

Symptoms:

Yellowing shoots in summer; by late summer many of these will be brown and dead. On clipped hedges the dieback can be quite pronounced, with the lower parts more severely affected than the top. A black powdery coating of sooty mould often develops on the stems and foliage.

Cause:

The damage is caused by greyish brown aphids (Cinara cupressi) which are active from May to November, reaching their peak in early to mid-summer. They suck sap from the stems and even quite light infestations can have a significant effect. Although the aphids are fairly large, 4mm long, they are difficult to see. A useful confirmation of aphid damage is the presence of the black sooty mould, as there are other causes of dieback on conifers. These include drought, scorching caused by wind or extreme temperatures, and root diseases such as honey fungus and phytophthora.

Control:

The key to control is “SPRAY EARLY” – it may be necessary to spray in early spring even if there is no visible sign of damage, it can be too late when signs of damage are visible. For commercial sprayers use Gazelle SG which offers excellent levels of control, or for domestic situations use Provado Ultimate Bug Killer.