Green spruce aphid

Unlike most aphids which are active during the spring and summer, the green spruce aphid is most active during the winter. It can cause needle drop on spruce trees (Picea species).

Green spruce aphid (Elatobium abietinum) on Spruce (Picea pungens). Credit: RHS/Entomology.

Green spruce aphid (Elatobium abietinum) on Spruce (Picea pungens). Credit: RHS/Entomology.

Quick facts

Common name: Green spruce aphid
Scientific name: Elatobium abietinum
Plants affected: Picea species especially Picea abies (Norway spruce or Christmas tree), Picea sitchensis (Sitka spruce) and Picea pungens (blue spruce)
Main symptoms: Pale blotches on foliage overwinter. Heavy needle drop. Small green aphids are present during winter
Most active: October to March

What is green spruce aphid?

Green spruce aphid is a sap-sucking insect that infests spruce trees (Picea species) causing needle drop.

Symptoms

  • Green spruce aphid is up to 2mm long, dull green with dark red eyes
  • It is most likely to be seen on spruce trees during late autumn to spring 
  • Old needles develop a pale mottled discolouration during the winter and many of these needles fall off in spring
  • A black sooty mould may be noticeable on stem joints
  • New growth produced in spring is unaffected, and its bright green appearance often contrasts strongly with the discoloured and sparsely foliated older stems

Control

Non-pesticide control

  • Natural enemies such as ladybirds, lacewings, hoverfly larvae and parasitic wasps may predate on the inactive nymphs in summer and help to limit infestations
  • Damaged trees can be helped to recover by keeping them watered during dry spells and feeding with a general fertiliser in spring
  • It can take several years for a badly damaged tree to regain an attractive appearance

Pesticide control

  • It is often difficult or impractical to spray large tree thoroughly, and in years when the aphid is abundant, some damage will occur
  • Little can be done to protect tall trees
  • Organic sprays, such as natural pyrethrum (e.g. Bug Clear Gun for Fruit & Veg, Ecofective Bug Killer), fatty acids (e.g. Solabiol Bug Free, Doff Greenfly & Blackfly Killer) or plant oils (e.g. Vitax Organic Pest & Disease Control, Bug Clear for Fruit and Veg) can give good control of aphids. These pesticides have a very short persistence and so may require reapplication to keep aphid numbers in check. Plant oil and fatty acid products are less likely to affect larger insects such as ladybird adults
  • More persistent insecticides include the synthetic pyrethroids lambda-cyhalothrin (e.g. Westland Resolva Pest Killer), deltamethrin (e.g. Provanto Ultimate Fruit & Vegetable Bug Killer) and cypermethrin (e.g. Py Bug Killer)
  • The systemic neonicotinoid insecticide acetamiprid (e.g. Bug Clear Ultra) is also available
  • Follow label instructions when using pesticides
  • Do not spray near plants in flower due to the danger to pollinating insects
  • Inclusion of a pesticide product does not indicate a recommendation or endorsement by the RHS. It is a list of products currently available to the home gardener

Download

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

Biology

  • The green spruce aphid differs from most other aphids by being active from autumn to spring, instead of spring and summer
  • The summer is spent as non-feeding nymphs
  • This aphid can be particularly damaging in mild winters, which enable it to breed more rapidly
  • Aphids should not be confused with other insects known as barklice or psocids. These insects are usually brown and often move rapidly over the plant, aphids usually remain fairly stationary. Psocids feed on algae and fungal spores and may be numerous on trees affected by sooty mould


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