Garden pests

Aphids

Aphididae (hundreds of species) · Insect

Also called greenfly (UK), blackfly (UK).

Illustration

Roses, vegetables, fruit trees, indoor plants and most othersSap-sucking insectSpreads by winged adults and infested plants

Small, soft sap-sucking insects that cluster on shoot tips and under leaves, curling new growth and leaving sticky honeydew. Squash or hose them off, and let ladybirds, hoverflies and parasitic wasps finish the job.

How to spot it

Clusters of soft, pear-shaped insects 1–7 mm long on shoot tips, buds and leaf undersides: green, black, yellow, pink, white or mottled.
Two small 'tailpipes' (cornicles) at the rear; some adults have wings.
Curled, distorted leaves and stunted shoots.
Sticky honeydew, black sooty mould and white cast skins on the leaves.
Ants running up and down the stems.

Easily confused with

Whitefly

Tiny white-winged insects that fly up when the plant is disturbed; aphids stay put.

Mealybugs

Coated in fluffy white wax, with no 'tailpipes' at the rear.

Scale insects

Shell-like bumps that don't move, stuck to stems and the undersides of leaves.

Where it's a problem

Worldwide: Hundreds of species attack most garden plants; Britain alone has more than 500.
Australia: Parasites and predators usually keep numbers down, so control is often not needed. Report unusual pests to the Exotic Plant Pest Hotline on 1800 084 881.
United Kingdom: The RHS advises tolerating aphids where possible: they are a vital food for wildlife, and natural enemies usually catch up.

What to do

Check shoot tips, buds and the undersides of leaves often; ants running up stems are a clue.
Squash small colonies with your fingers, or knock them off with a strong jet of water from the hose.
Prune off badly infested shoots.
Leave ladybirds, hoverflies, lacewings and parasitic wasps to work; aphid 'mummies' mean the wasps are already at it.
Keep ants off the plant, as they guard aphids from predators, and go easy on nitrogen fertiliser, which speeds aphid breeding.
Tolerate light infestations where you can.

If you use an insecticide, choose one labelled for aphids and follow the label and local rules. Sources say broad-spectrum sprays also kill the ladybirds, hoverflies and wasps that keep aphids in check.

Not sure it's this one? Scan it free All garden pests

Free account, no card needed. You sign up or sign in first, then the scanner opens.

Sources

Facts checked Sunday 27 September 2026. General guidance only: follow your local council, agency and product label.