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Cypress aphid is one of the causes of dieback on conifer hedges. It has become an increasingly problematic on conifer hedges since the 1980s, particularly on Leyland cypress.
Common name Cypress aphidScientific name Cinara cupressivoraPlants affected Cupressus macrocarpa, Lawson's cypress (Chamaecyparis lawsoniana), Leyland cypress (× Cuprocyparis leylandii) and ThujaMain symptoms Conifer hedges suffer extensive drying up and browning of the foliage in late summerMost active April-June
Cypress aphid is a blackish brown sap-sucking insect that infests the stems of some hedging conifers (Cupressus species especially C. macrocarpa, Thuja occidentalis, Chamaecyparis lawsoniana and x Cuprocyparis leylandii) in early summer. This often causes a gradual drying up of the foliage.
There are a number of aphid pests of other conifers and aphid like adelgids can also affect these plants
A hedge that is cared for and pruned during the growing season will be more resistant to cypress aphid damage
Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)
Damage is caused by greyish brown aphids that are active from May to November, reaching peak numbers in early to mid-summer.
Adelgids AphidsAphid predatorsBlackfly Chemical labels explained Chemicals: using a sprayer Chemicals: using safely and effectively Cherry blackfly Conifer aphidsConifer careConifers: brown patchesConifers: Pestalotiopsis diseaseCurrant aphids Currant blister aphid Fruit aphids Green spruce aphidHarlequin ladybird Hellebore aphids Juniper scaleLadybirds Leyland cypress: pruningLupin aphid Mealy cabbage aphid Pear bedstraw aphid Plum aphids Privet aphid Raspberry and blackberry aphids RHS statement on pesticides in horticulture Rose aphids Rose root aphid Rosy apple aphid Sooty mouldsWaterlily pests Willow bark aphid Woolly aphid
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