16 Common Garden Pests

You can identify pest damage in one of two ways: You see the insect or the damage it causes. Use chemical sprays only as a last resort. Where possible, try pest traps and barriers, biological controls and organic sprays first.
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Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Photo By: DK - How to Grow Practically Everything © 2010 Dorling Kindersley Limited

Red Spider Mites

The tiny mites live under leaves and suck sap, causing yellow mottling. Fine webs are sometimes visible. Raise humidity and use a biological control under glass. Otherwise try organic sprays.

Gall Mites

These microscopic mites suck sap and cause abnormal growths. These include raised pimples or clumps of matted hairs on leaves, or enlarged buds. Most are harmless and can be tolerated.

Leaf Miner Damage

The larvae of various flies, moths, sawflies and beetles feed within the leaves, creating discolored blotches or surface trails. Most leaf miner damage is relatively harmless and can be left untreated.

Box Sucker

The wingless nymphs of box psyllids are covered in a waxy coat, and found inside the ball-shaped shoot tips in spring. Control the pest by cutting off affected growth; discard.

Codling Moth

To avoid maggots in apples, spray emerging caterpillars twice using bifenthrin, starting in midsummer. Also hang pheromone traps in late spring to catch male moths and prevent them from mating.

Winter Moth

In spring, the leaves of fruit trees are webbed together and hide green caterpillars inside. Holes are visible when leaves expand. Apply sticky traps to capture adult moths.

Scale Insects

Tiny blister or shell-like bumps on leaf backs result in poor growth. Other symptoms are sticky excretions and sooty mold on evergreens. Wash off mold, and spray with horticultural oil.

Whitefly

Under glass, hang yellow sticky pads to trap the tiny white flying adults, which suck sap from plants; use a biological control (Encarsia wasp) on larvae or spray with organic chemical controls.

Viburnum Beetle

Both the adults and larvae eat holes in the leaves, mainly on Viburnum tinus and V. opulus; this can slow growth and looks unsightly. Spray badly affected plants in spring with bifenthrin or thiacloprid.

Thrip

This tiny black sap-sucker, known as "thunder fly," cause white patches on the petals and leaves of indoor plants, and also peas, leeks, onions and gladioli. Use biological controls.

Vine weevil Larvae

Small cream grubs with a brown head feed on plant roots, especially those growing in containers or with fleshy roots. This can cause plants to suddenly collapse.

Adult Vine Weevil

The adult beetle is nocturnal, flightless and makes notches in leaves. Use a biological control (nematodes).

Cabbage White Caterpillars

These voracious eaters decimate brassicas and nasturtiums. Rub off egg clusters and pick off any caterpillars you find.

Tomato Moth

The tomato moth damages fruits. Pick off any caterpillars you find.

Sawfly Larvae

The caterpillar-like larvae devour the foliage on plants such as roses, gooseberries and Solomon's seal.

Sawfly Damage

Leaf rolling is usually the first sign of sawflies. Pick caterpillars off by hand or spray with bifenthrin or pyrethrum.

Woolly Beech Aphid

Seen in early summer, these white fluffy aphids coat shoots and the undersides of leaves. They suck sap and excrete honeydew that supports black sooty mold.

Earwig

Mostly beneficial, earwigs are nocturnal and feed on dahlia, chrysanthemum and clematis flowers. Lure them into upturned flower pots filled with straw and release them elsewhere.