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Mealybugs

Mealybugs

Family Pseudococcidae

Insect

Soft, slow-moving sap-suckers that hide under a coat of white, cottony wax in leaf joints and along stems, weakening the plant and dripping sticky honeydew. They are most familiar as a stubborn pest of houseplants but also hit greenhouse plants, citrus, and warm-climate crops.

🔎 How to spot it

Look for small, oval, soft insects, up to about a fifth of an inch, dusted in white mealy or cottony wax with little wax filaments around the edge, clustered where leaves meet stems, along veins, and in other tucked-away spots. Cottony egg masses, sticky honeydew, and black sooty mold often appear with them. The crawlers are tiny and move slowly before settling.

🥀 Damage it causes

Mealybugs suck sap and weaken the plant, yellowing and sometimes dropping leaves, stunting growth, and distorting new shoots when they feed on tender tips. Their sticky honeydew coats the foliage and grows black sooty mold that blocks light. Heavy, untreated infestations can slowly kill a houseplant.

🛡️ Prevent it

Inspect new plants carefully, especially leaf joints and undersides, and isolate new arrivals before adding them to a houseplant collection, since mealybugs ride in on infested plants. Avoid over-fertilizing with nitrogen, which fuels the soft growth they favor, and wipe down and watch any plant that has had them before.

🧯 If it is already here

Dab individual mealybugs and egg masses with a cotton swab dipped in rubbing alcohol, and wash colonies off with a firm spray of water. For wider infestations, treat with insecticidal soap, horticultural oil, or neem, repeating every week or two to catch newly hatched crawlers, and remove badly infested leaves or whole plants. Control ants, which protect mealybugs for their honeydew.

💡 Good to know

Mealybugs are slow to move but very persistent, and repeat treatments are almost always needed because the waxy coat shields them and eggs keep hatching. Outdoors their many natural enemies, including the aptly named mealybug destroyer lady beetle and parasitic wasps, usually keep them down unless ants are tending them.

🌱 Plants it attacks

714 plants in the library can be attacked by this pest

Acorn SquashAdirondack Blue PotatoAdzuki BeanAfrican Blue BasilAfrican MarigoldAgapanthusAgeratumAgrimonyAji Amarillo Pepper🍓Albion StrawberryAlice du Pont Mandevilla🥔All Blue PotatoAlmondAloe VeraAmbrosia CornAmerican BasswoodAmerican Beauty Dragon FruitAmerican BeechAmerican PersimmonAmethyst Falls WisteriaAmish Paste TomatoAnaheim PepperAnemoneAngelique TulipAngeloniaAniseAnise HyssopAnjou PearAnnabelle Smooth HydrangeaAnnual VincaApeldoorn TulipApple MintApril Tryst CamelliaArbequina OliveArizona Sun Blanket FlowerArkin CarambolaArmenian CucumberAroniaArp RosemaryArugulaAshwagandhaAsian PearAsian PersimmonAtemoyaAtlantic Giant Pumpkin🥕Atomic Red CarrotAucubaAugust Beauty GardeniaAunt Molly's Ground CherryAutumn Joy SedumAvocadoBachelor's ButtonBalsam FirBalsam PoplarBanana PepperBarbara Karst BougainvilleaBartlett PearBay LaurelBayberryBeach PlumBeauregard Sweet PotatoBecky Shasta DaisyBee Balm🍅Beefmaster TomatoBenarys Giant ZinniaBengal Tiger CannaBetter Boy Tomato🥬Bibb Lettuce🍅Big Beef TomatoBig Boy TomatoBilberryBing CherryBitter MelonBlack BeanBlack Beauty EggplantBlack Beauty ZucchiniBlack Beluga LentilBlack Cherry TomatoBlack CrowberryBlack Currant🍉Black Diamond WatermelonBlack Kabouli ChickpeaBlack Krim TomatoBlack RaspberryBlack Sapote🥬Black Seeded Simpson Lettuce🥕Black Spanish RadishBlack Tartarian CherryBlack WalnutBlack-Eyed PeaBlack-eyed Susan VineBlood OrangeBloomsdale SpinachBlue Bird DelphiniumBlue Bird Rose of SharonBlue FescueBlue Lake Green BeanBluecrop BlueberryBocking 14 ComfreyBok Choy

For educational and informational purposes only. Pest control advice is general guidance drawn from university cooperative extension sources; always identify a pest positively and read and follow the label on any product before use, especially around food crops, children, and pets.