Understanding Cherry Aphids: Symptoms and Control Measures
Cherry Aphid Symptoms
Cherry aphids, commonly known as cherry leaf aphids, infest cherry trees by feeding on the sap from the underside of cherry leaves. Their feeding causes the edges of the leaves to swell and curl upwards, forming characteristic gall-like swellings. Initially, these swellings appear as small greenish-red bumps with openings on the underside of the leaf. As the infestation progresses, the galls enlarge and turn yellow-white to yellow-brown. Severe infestations can lead to premature leaf drop, weakening the tree and reducing fruit development and yield. Additionally, it can affect the differentiation of flower buds, impacting next year's yield as well.
Control Measures
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Manual Control: Typically performed in March to April when the galls start turning yellow-white, manual control involves picking off infested leaves and destroying them in a safe area by burning.
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Chemical Control: Use environmentally friendly pesticides to minimize residue on cherry fruits. Apply Beauveria bassiana formulations twice when most of the overwintering eggs have hatched. If Beauveria bassiana takes effect slowly, it can be supplemented with a 10% pyridaben wettable powder at a concentration of 2000-2500 times to control aphids and reduce population density.
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Biological Control: Utilize natural predators of cherry aphids, including ladybugs, parasitic wasps, spiders, lacewings, and predatory mites. Introducing these natural enemies can effectively reduce aphid populations and mitigate damage to cherry trees.
Cherry aphids not only infest cherries but also affect other fruit trees such as walnuts and peaches. It's crucial to promptly address aphid infestations to prevent significant damage to the trees.
