The main danger posed by the apple dimpling bug occurs between early pink and petal fall.
Apple dimpling bug
The danger is particularly acute if fruit tree flowering coincides with the flowering of native trees in surrounding bush. In particular be aware of wattle, tree lucerne and Geraldton wax.
Orchardists need to maintain vigilance on blocks or rows that neighbour native trees and shrubs.
Where possible, removal of native vegetation is recommended.
See this article in Tree Fruit Sept 2019