Aphids occur for 16-18 generations a year, and nymphs aged 1-2 years old overwinter in groups at decay scars, saw openings, etc., and begin to be active after germination in the second year.
From late May to mid-June, the population of aphids reaches its first peak of the year.
From late June to mid-July, the population of aphids rebounded again, forming the second peak of the year.
In early to mid-September, the third peak is reached, after which apple aphids will enter a wintering state as the temperature drops below 8 °C.
For control: we should focus on the prevention and control during the dormant period when spraying dry branches and before flowering, spray chlorpyrifos and permethrin compound drugs, and focus on spraying the scars and saws evenly. If there are still aphids on individual trees after bagging, add borer thiophos when spraying Bordeaux liquid
