Aloe
Symptom Cause  
Leaves curled and discolored; honeydew evident on undersides of leaves, sometimes sooty mold forms
Aphids
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Cottony insects underside of leaves, stems, crotches; honeydew apparent; sooty mold
Citrus Mealy bug
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Tiny insects fly when plant disturbed; roots damaged, seedlings may die
Fungus Gnats
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Cottony insects underside of leaves, stems, crotches; honeydew apparent; sooty mold
Longtailed Mealy bug
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White, cottony masses on roots and stems, above/just below surface; plant wilts, yellows
Root Mealy bugs
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Leaves yellow, drop; bumps on leaves and stems; sometimes sticky material on leaves
Scale
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Leaves stippled, yellowing or bronze; dry out and drop may be webbing visible; sometimes galls form on leaves
Spider Mites
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Leaves mottled, yellow; tiny white insects feeding underside of leaves
Whiteflies
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