An insecticide treatment for the aphid should be applied before blossom if the economic threshold of 50% of blossom trusses infested with 5 or more aphids is exceeded. Insecticide sprays should only be applied for this pest if strictly necessary as it provides an early food source for natural enemies of other more damaging species.
- Several insecticides are approved for control of aphids on apple but if apple grass aphid is the only pest that needs to be controlled, flonicamid (Mainman) is the preferred choice in conventional orchards as it is selective and partially systemic.
- A full approval for spirotetramat (Batavia) on apples for the control of sucking insect pests will control apple grass aphid, but growers may prefer to reserve its use for more difficult to control species such as woolly 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 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’.
- The neonicotinoid acetamiprid (Gazelle) is also approved for control of aphids on apple though it can be a little slow acting in cool conditions.
- It is systemic and is highly effective against aphids. It will give excellent control of apple grass aphid and incidental control of several other pests such as capsids and sawfly.
- It has little effect against caterpillars and acetamiprid (Gazelle) is ineffective against woolly aphid.
- Use of synthetic pyrethroids, which are harmful to natural enemies, should be avoided.
Insecticides approved for control of aphids on apple
| 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, codling & tortrix moths, capsid, sawfly, apple sucker | 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 | neonicotinoid | selective | Aphids and woolly aphid | safe |
| maltodextrin | Eradicoat Max | polysaccharide | broad spectrum | Aphids, mussel scale, spider mite | harmful |
| spirotetramat | Batavia | tetramic acid derivative | selective | Sucking insect pests | unclassified |
| Choice of insecticides – Safety factors | |||||||
|---|---|---|---|---|---|---|---|
| Hazards | Harvest interval (days) | Max. no. sprays | Buffer zone Width (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 |
| fatty acids | no | h, i | h | u | 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, t=toxic, c=closed cab required for air assisted sprayers, sm=statutory minimum of 5 m for broadcast airassisted sprayers u=uncategorised/unclassified/unspecified | |||||||