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Black Walnut Honeydew: Aphid Control on Large Trees

KC black walnut grove; deck tree produced sticky honeydew first time in 11 years. No visible pests. Covers everything.

Cause: Aphids/Scale → Honeydew → Sooty Mold

Sucking insects excrete sugar-rich honeydew → black sooty mold grows on it.

Insecticide Options

Contact: Acephate (Orthene), bifenthrin (Talstar), chlorpyrifos (Dursban), diazinon, malathion, nicotine sulfate, pyrethrum, rotenone, resmethrin, tetramethrin+sumithrin. Rotate if resistance suspected.

Systemic: Acephate (Orthene), others (restricted use). Soil-applied = less beneficial insect harm.

Ask nursery for tree-aphid systemic. Full foliar spray on large tree = professional job.

Trees: Pecan Tree Dripping Sticky Honeydew? Aphid Control for a Clean Driveway; Honeydew from Linden Trees: Systemic Insecticide for Aphid/Scale Control; Chinese Pistache Oozing Black Sap: Borer or Slime Flux?; Black Walnut Sawdust Dog Toxicity: Mold Risk, Not Juglone; Black Rot on Grapes/Apples: No Threat to Walnut Trees; Planting Hybrid Maples Near Black Walnut: Juglone Tolerance; Oak Tree Honeydew on Cars: Aphid/Scale Systemic Fix; Sticky Sap Dripping from Oak: Aphids or Scale; Black Walnut Sap on Treated Wood Arbor: No Damage; Black Leaves on Ornamental Pear: Sooty Mold from Aphids

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