Green apple aphid

The green apple aphid (Aphidula pomi) is a prominent agricultural pest belonging to the order Hemiptera and the family Aphididae. It is considered a significant threat to pome fruit production, as it maintains a permanent residence on apple trees throughout the entire growing season, impacting tree health and fruit quality.

This species primarily targets apple trees (Malus domestica), although it can also infest pear, quince, and various hawthorn species. Aphids preferentially attack the youngest, succulent growth, including terminals of shoots and the undersides of young leaves, where they can easily penetrate the plant tissues to feed on phloem sap.

The biology of this pest involves a cycle without host alternation, meaning it remains on the same tree species all year round. The winter stage consists of shiny black eggs laid on the bark of young shoots. Upon hatching in spring, the aphids start reproducing asexually, leading to numerous generations per year, with population surges often occurring in late spring and early summer.

The damage caused by Aphidula pomi is characterized by leaf curling, stunted shoot growth, and premature leaf drop. Beyond direct nutrient extraction, the aphids secrete honeydew, which promotes the growth of sooty mold. This fungus blocks photosynthesis and can severely weaken the tree's physiological status, leading to reduced vigor and smaller fruit size.

Integrated pest management (IPM) is essential for controlling this pest. This includes maintaining healthy trees through balanced fertilization and encouraging natural enemies such as lady beetles, hoverflies, and lacewings. Chemical control should be implemented early in the season, targeting the aphids before leaf curling provides them with a physical shelter from contact insecticides.

• Pruning of water sprouts to reduce feeding sites.
• Implementation of biological control using predator release.
• Targeted application of systemic insecticides.
• Regular field scouting to detect early spring colonization.