Rosy apple aphid: Direct control with Neem in organic orchards (Biofruitnet Practice Abstract)

Summary

Neem penetrates the leaves and is absorbed through the feeding activity of the pest. It also helps to control other aphid species such as D. devecta and partially against Aphis pomi.
Practical recommendation
• Check for infested leaves regularly in Spring. Rosy apple aphids are black and may appear in large colonies on the lower side of young leaves. The damage threshold is at a single aphid. Damaged fruits remain small and shrivel.
• Apply Neem from BBCH-stage 57 - “Red Bud”):
o Before the stem mothers (fundatrices) develop into adults. None or only a few young aphids will develop and colonies will not form.
o When stem mothers are already adults. Aphids will not develop to adults unless the fundatrices produce progeny for a prolonged period. In this case, split the application at red bud stage and at the end of blossom. Neem inhibits the early stages of development.
• If aphid colonies are too far advanced in their development, the treatment will not have effect. The correct treatment period is crucial!
• Treat once or twice based on the infestation pressure, the aphid and the vegetation development. With the splitting method, the application rate per treatment can be reduced.