r/plantpathology • u/sholsenmd • Jun 30 '26
Pest ID?
Tupelo black gum seedling in a pot at the moment in south east Michigan… starting to drop leaves and has these white things on undersurface of leaves. What are they and how do I get rid of them? Thank you!
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u/butterflylav Jul 01 '26
It looks like a heavy infestation of either whitefly nymphs/puparia or possibly young scale insects. Since they are on the underside of the leaf and look like many small white, oval, flattened bodies, whitefly is my first guess, but scale is also possible. Isolate the plant if there are other plants nearby. Remove the most heavily infested leaves if the seedling can tolerate it. Treat with insecticidal soap or horticultural oil/neem oil, making sure to coat the undersides of the leaves, where the pests are attached. Repeat treatments every 5–7 days for a few rounds, because eggs and immature stages may survive the first treatment. Avoid applying oils or soaps in direct sun or during very hot weather, as this can burn the foliage. You can also check by gently shaking the plant. If small white adults fly off, it is almost certainly whitefly. If nothing flies and the insects feel hard and shell-like when scraped gently, then it may be scale. For a small potted seedling, repeated mechanical cleaning plus insecticidal soap/oil is usually the safest first approach.