Mealybugs: Causes, Diagnosis & Fixes
Mealybugs are soft-bodied, sap-sucking insects covered in a white, waxy coating. They cluster in leaf joints, on stems, and under leaves.
Quick diagnosis
Mealybug treatment requires patience and persistence. Treat all crevices thoroughly and repeat applications to catch newly hatched nymphs.
考えられる原因
Introduction from Infested Plants
Why: Mealybugs commonly arrive on new plants purchased from nurseries or received from others.
Signs to check: White cottony masses appeared after introducing a new plant.
Warm Indoor Conditions
Why: Indoor warmth and lack of natural predators allow mealybug populations to grow unchecked.
Signs to check: Population grows steadily, no natural predators present indoors.
Overfeeding with Nitrogen
Why: Excess nitrogen produces soft, lush growth that is more attractive and vulnerable to mealybugs.
Signs to check: Plant has very lush, soft foliage, mealybugs concentrate on new growth.
確認ポイント
- 1Look for white, cottony clusters at leaf joints and stem bases
- 2Check leaf undersides and where leaves meet stems
- 3Look for sticky honeydew residue on and below the plant
- 4Inspect nearby plants for signs of spread
対処法
- Isolate the plant from others immediately
- Dab individual mealybugs with a cotton swab dipped in 70% rubbing alcohol
- Spray the entire plant with insecticidal soap, focusing on crevices
- For heavy infestations, apply neem oil solution every 7-10 days
- Repeat treatments for at least 3-4 weeks, as eggs may survive initial applications
専門家に相談するタイミング
- Mealybugs are found on roots (root mealybugs require soil drench treatment)
- Plant is severely weakened with significant leaf drop
- Infestation keeps returning despite repeated treatments
ポイント
Mealybug treatment requires patience and persistence. Treat all crevices thoroughly and repeat applications to catch newly hatched nymphs.
Frequently asked questions
What causes mealybugs in houseplants?
Mealybugs are soft-bodied, sap-sucking insects covered in a white, waxy coating. They cluster in leaf joints, on stems, and under leaves. Common causes include introduction from infested plants, warm indoor conditions, overfeeding with nitrogen.
How do I fix mealybugs?
Start by identifying the likely cause instead of applying every remedy at once. Isolate the plant from others immediately Dab individual mealybugs with a cotton swab dipped in 70% rubbing alcohol Spray the entire plant with insecticidal soap, focusing on crevices
Track the problem over time
アプリで回復を追跡
進捗を記録し、リマインダーを設定し、AI による診断を受けましょう。
Sources and review
Content last reviewed: September 4, 2026
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