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Aphids

Aphids

Superfamily Aphidoidea

Insectalso: Greenfly, Blackfly, Plant lice

Tiny, soft-bodied sap-suckers that cluster on tender new growth and the undersides of leaves. They are the single most common garden pest, turning up on nearly every crop. Most healthy plants shrug off light feeding, but colonies build fast and a few species spread plant viruses.

🔎 How to spot it

Pear-shaped insects about the size of a pinhead, in green, yellow, brown, red, or black depending on the species and the host plant. The giveaway is a pair of short tubes (cornicles) projecting from the rear end. They feed in dense clusters on leaf undersides and new shoots and move slowly when disturbed. Watch for curled or yellowing leaves, stunted shoots, and a sticky, shiny coating (honeydew) that often turns black with sooty mold and draws ants.

🥀 Damage it causes

Aphids pierce stems and leaves to suck plant sap, which yellows and curls foliage and stunts new growth. Their honeydew coats leaves and fruit and grows black sooty mold. Some species inject toxins that distort leaves, and a number of aphids transmit plant viruses as they feed, which is often more damaging than the feeding itself.

🛡️ Prevent it

Go easy on nitrogen fertilizer, since soft, lush growth draws aphids; choose slow-release sources. Inspect new transplants before planting them. Keep down weeds like sowthistle that harbor aphids. Protect seedlings with floating row cover or reflective silver mulch, and plant flowering herbs nearby to invite the predators that keep aphids in check.

🧯 If it is already here

Knock colonies off with a strong jet of water, repeated every few days. Pinch off and destroy heavily infested shoots and leaves. Encourage or release natural enemies. For stubborn infestations, coat the insects, especially the leaf undersides, with insecticidal soap or horticultural oil, avoiding hot or drought-stressed days. Control the ants that farm and protect aphids using sticky bands or bait.

💡 Good to know

Aphids reproduce explosively: females give live birth to as many as 80 young in a week, and nymphs mature in about a week, so colonies seem to appear overnight. A healthy beneficial-insect population usually keeps them in check, including lady beetles, lacewing and hover fly larvae, soldier beetles, and tiny parasitic wasps that leave behind papery, swollen aphid mummies. Ants farm aphids for their honeydew and fight off these predators, so controlling ants lets the beneficials do their work.

🌱 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.