Hellebore aphid

What is hellebore aphid?

A sap-sucking aphid or greenfly that infests the flowers and foliage of hellebores in the spring.

Symptoms

• Whitish-green aphids, 2-4mm (about 1/8in) long, sometimes form dense colonies on the underside of hellebore leaves and flowers in early spring.
• The sugary honeydew they excrete can also encourage unsightly sooty moulds on the foliage.

Control

• Aphids can be controlled by using the systemic insecticides thiacloprid (Provado Ultimate Bug Killer concentrate or ready to use), acetamiprid (Scotts Bug Clear Ultra concentrate or Bug Clear Ultra Gun ready to use) or thiamethoxam (Westland Plant Rescue Bug Killer Ornamental Plants).
• Pesticides containing deltamethrin (BayerSprayday Greenfly Killer) or lambda cyhalothrin (Westland Plant Rescue Fruit & Vegetable Bug Killer) can also be used for aphid control.
• If plants are in flower, spray in the evening when bees are not active.

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Pesticides for gardeners (Adobe Acrobat pdf document outlining pesticides available to gardeners)

Biology

• Although this aphid can be present on hellebores all year round, noticeable infestations only occur in early spring at flowering time.
• It is possible this aphid may also be responsible for spreading the serious virus disease known as hellebore black death.