Identifying Common Apple Pests in the Orchard

Getting to Know the Pests in Your Orchard

There is no better teacher than a daily wander among your trees. Ten minutes with a mug of tea, looking under leaves and turning a few fruits, will tell you more about what is happening in your orchard than any book. Most apple problems are caused by a small handful of characters, and once you can read the signs they leave behind, you can act early and gently rather than reaching for the heaviest spray on the shelf.

The three you are most likely to meet are codling moth, aphids and winter moth. Each has its own season and its own signature damage, and each responds well to a bit of patience, good hygiene and well-timed intervention. Learning to tell them apart is the whole game.

Codling Moth: the Maggot in Your Apple

Codling moth is the reason for that sad moment when you cut into a beautiful apple and find a tunnel of brown frass running to the core. The adult is a small, grey-brown moth that flies on warm evenings from late May into July, usually around dusk. She lays single eggs on leaves and young fruit, and the tiny caterpillar hatches a week or so later, chewing its way in – often through the eye at the base or the side of the fruit.

Look for:

• Small entry holes, sometimes with reddish-brown frass pushed out
• A tunnel running from the skin towards the core, with seeds often eaten
• Fruit dropping early in late summer, often with a maggot already gone
• Sticky pheromone traps catching moths from late May onwards, which tells you when to act

The caterpillar leaves the fruit to pupate in bark crevices or in the soil at the base of the tree. That is the weak point. Corrugated cardboard bands tied around trunks from July will collect larvae looking for somewhere to pupate – take them off and burn or bin them in late autumn. Clear up fallen fruit promptly, and let chickens or pigs in under the trees if you keep them, as they will hoover up larvae in the soil.

For a gentle spray, a codling moth granulovirus applied from late June will kill the caterpillars without touching anything else. Because it only works on young larvae, timing matters more than strength.

Aphids: Curling Leaves and Sticky Honeydew

Aphids are far less destructive than codling moth, but they make trees look miserable. The rosy apple aphid is the worst offender, arriving in spring and feeding on the underside of leaves, which curl tightly and pucker. If it gets into the blossom truss, young fruitlets can be stunted and misshapen. Green apple aphid builds up on soft new shoots in summer, and woolly aphid forms white cotton-wool colonies on branches, causing galls and cracked bark.

Tell-tale signs:

• Curled, blistered leaves with clusters of green, pink or grey insects inside
• Sticky honeydew on leaves and fruit, which attracts ants and grows sooty mould
• White cottony fluff on twigs and wounds
• A steady procession of ants running up and down the trunk, farming the aphids for honeydew

Before you do anything, look closely – you will often find ladybird larvae, hoverfly maggots or lacewing larvae in the middle of the colony. Earwigs are also excellent aphid predators and worth tolerating. A strong jet of water knocks aphids off, and pinching out badly curled shoot tips removes the worst of them. Avoid feeds high in nitrogen, which push soft, sappy growth that aphids adore. Dormant-season oil washes in winter smother overwintering eggs, and horticultural soap applied on a cool, still evening will deal with stubborn colonies without harming bees.

Winter Moth: Caterpillars That Appear from Nowhere

The winter moth is a peculiar creature. The male flies, but the female has tiny, useless wings and must crawl up the trunk from November to January. Once mated, she lays eggs in bark crevices, and those eggs hatch in spring, just as buds are bursting. The young caterpillars are loopers – they move in a hungry hump-backed shuffle – and they will quietly strip buds, blossom and young leaves in April and May. A heavy infestation can leave a tree looking as if it has been scorched, and fruitlets can be bitten and lost.

Because the females walk rather than fly, grease bands wrapped around trunks in October are wonderfully effective. Fit them tightly, with no gap for a determined moth to squeeze through, and keep them sticky right through the winter. Later in spring, the caterpillars are often spotted dangling on silken threads when you brush past a branch – a useful moment to check how heavy the population is. Blue tits and great tits do sterling work on them, so hang nest boxes and leave some untidy corners where birds can forage.

Bringing in the Pest Patrol

An orchard that hums with life is an orchard with fewer problems. Ladybirds, hoverflies, lacewings, ground beetles, earwigs, spiders and birds all take a share of your pests, and they need somewhere to live. Allow a little wildness: nettle patches, umbellifers such as cow parsley, and nectar-rich flowers like phacelia and calendula will feed the adults of predatory insects. Leave fallen leaves in the corners, and avoid clearing every last bit of loose bark. Feed the soil with compost rather than quick-acting fertiliser, and keep grass mown but not scalped.

The golden rule is never to spray during blossom. Even the gentlest product is no good to you if it takes the bees with it.

Timely Controls Through the Year

Small, well-timed actions beat big, late ones every time. Try to work to a rhythm like this:

• October to January: fit grease bands for winter moth, scrub trunks, and apply a dormant oil wash if aphids were bad last year
• Late May to July: hang pheromone traps for codling moth, check them weekly, and treat with granulovirus once moths are caught
• June onwards: clear fallen fruitlets, and band trunks with corrugated cardboard from July
• Spring: watch for curled leaves, hose off aphid colonies, and welcome the predators that turn up
• All year: keep the ground beneath trees tidy, and tolerate a little damage – a few maggoty apples are the price of a living orchard

Get into the habit of looking closely and often, and you will spot trouble while it is still small. That is what gentle, effective orchard keeping really means.