Skip to Content Skip to HDC Navigation Skip to Apple Best Practice Navigation

Green apple aphid (Aphis pomi Degeer)

Green apple aphid

Green apple aphid is a common but minor pest of apple, which also attacks pear. It is most important on young trees.  As the name implies it is bright green in colour and readily distinguished from other aphid pests of apple.

The life cycle starts when the aphid hatches in April at green cluster from overwintered eggs on the bark but the spring colonies that develop in shoot tips are of little importance.

Winged forms develop in summer, which migrate to the growing shoots of other apple trees.

Large, dense colonies develop along the lengths of the shoots from these migrants in summer and it is these that are damaging. The colonies have a strong distinctive smell.

Fruits in the vicinity of and below colonies become heavily contaminated with honeydew which becomes blackened by sooty mould and cast aphid skins. The colonies are usually attended by black ants.

The severity of infestation by green apple aphid should be determined in each orchard when pest assessments are done from late June to the end of August. Application of an insecticide to control green apple aphid should be considered if more than 10% of shoots have infestations causing leaf curling.

Control  

Many insecticides are approved for control of aphids on apple but if aphids are the only pests that need to be controlled, flonicamid (Mainman) is the preferred choice in conventional orchards as it is selective and partially systemic.

  • The neonicotinoid acetamiprid (Gazelle) is also highly effective. It will also control various other pests such as mussel scale.
  • A full approval for spirotetramat (Batavia) on apples for the control of sucking insect pests will control green apple aphid, but growers may prefer to reserve its use for more difficult to control pests such as woolly aphid and rosy apple aphid. It must be applied after flowering and works best when pests are moving from brown wood to green tissue. It will prevent population build-up but does not offer pest ‘knockdown’.
  • A recent EAMU for Flipper (fatty acids) has increased the available options should growers wish to reserve other insecticides for control of pests later in the season. It is known to complement the use of Batavia as it provides quick ‘knockdown’.
  • Use of synthetic pyrethroids, which are harmful to natural enemies, should be avoided.

 

Insecticides approved for use on apple which are recommended to control green apple aphid or offer some incidental control when applied to control other pests or diseases

Choice of insecticides – efficacy factors

Active ingredient Trade name (examples) Class Selectivity Approved for control of Safety to Typhs 
acetamiprid Gazelle neonicotinoid broad-spectrum, systemic Aphids safe
deltamethrin Decis Forte etc. pyrethroid broad spectrum Aphids, apple sucker, capsids, caterpillars, codling & tortrix moths, sawfly harmful
dodecylphenol ethoxylate Agri 50E physical acting insecticide broad spectrum Aphids, leafhoppers, mealy bugs, spider mites harmful
fatty acids Flipper (EAMU 3419/19) bioinsecticide broad spectrum Aphids, blossom weevil, two-spotted spider mite unspecified but generally safe in IPDM programmes
flonicamid Mainman chlordotonal organ modulator selective Aphids and woolly aphid safe
maltodextrin Majestik polysaccharide broad spectrum Aphids, spider mites harmful
spirotetramat Batavia tetramic acid derivative selective Sucking insect pests unclassified

Choice of insecticides – Safety factors

  Hazards Harvest interval(days)  Max. no. sprays Buffer zoneWidth (m)
Anticholin-esterase?  Humans Fish & aquatic life Bees
acetamiprid no u t u 14 2 20
deltamethrin no h, i ed d 7 u 50
dodecylphenol ethoxylate no u u u 0 u u
fatty acids no h, i h d 0 8 20
flonicamid no u h u 21 3 sm
maltodextrin no i d d 0 20 sm
spirotetramat no h, i t d Start of ripening 2 10
h=harmful, i=irritant, d=dangerous, ed=extremely dangerous, c=closed cab required for air assisted sprayers, sm=statutory minimum of 5 m for broadcast airassisted sprayers u=uncategorised/unclassified/unspecified

 

Control in organic orchards

Green apple aphid should be tolerated in established organic apple orchards because the pest only causes minor damage.

  • Emphasis should be placed on cultural control measures such as the provision of artificial refuges for earwigs and lacewings and of flowering herbs in and around the orchard to encourage predatory insects.
  • Where significant damage is being caused especially to young trees, as a last resort, localised, high volume sprays of fatty acids should be applied when damaging infestations develop on young trees in summer if necessary.

 

 Further reading

 

 

This entry was posted in Uncategorised. Bookmark the permalink.

Leave a Reply

Your email address will not be published.