Codling moth
Cydia pomonella
Its caterpillars tunnel to the core of apples and pears, leaving frass-filled exit holes. Hang pheromone traps from late spring and pick up windfalls promptly.
The moth is small, gray and mottled with a coppery patch at the wingtip, and flies at dusk in early summer. What you find is the caterpillar: pinkish-white with a brown head, in a tunnel running to the core, and a hole plugged with wet brown frass.
- A single hole in the side or the eye of the fruit, ringed with crumbly brown frass.
- A brown tunnel driven to the core, with the seeds eaten and the cavity fouled.
- Fruit ripening and dropping early, small and misshapen.
- Pinkish caterpillars found when apples are cut at harvest.
- Damage discovered only in store, in fruit that looked sound when picked.
Overwinters as a full-grown caterpillar in a silk cocoon under loose bark, in crevices and in store sheds. Moths fly from late May to July, laying single eggs near young fruit; the caterpillars enter within days, feed for a month, then leave the fruit to spin up. A second generation follows in a warm summer.
Warm, still evenings in June and July — the moths need calm weather above about 15 °C to fly and mate, so a cold wet early summer is a good apple year.
- Hang pheromone traps from mid-May, one per few trees: they catch males, and more usefully they tell you exactly when the flight is on.
- Tie corrugated cardboard bands around the trunks in midsummer to catch the caterpillars spinning up, and burn the bands in winter.
- Collect and destroy windfalls and infested fruit promptly rather than leaving them under the tree.
- Encourage blue tits with nest boxes — they hunt overwintering cocoons out of the bark all winter.
- Apply codling-moth nematodes to the trunk and main branches in autumn on a damp mild evening.
- Scrape loose bark and clear crevices on old trees in winter, where the cocoons sit.
- Keep the orchard floor clear of fallen fruit through the whole season.
- Grease-band and inspect trunks; the same bands catch winter moth as well.
- Store fruit in clean, sealed crates and check them, since caterpillars pupate in store.
- Grow a few early varieties, which are often picked before the second generation lands.
Apples above all, plus pears, quinces and occasionally walnuts.
- BatsChiroptera A single bat takes hundreds of moths and mosquitoes in a night, and the moths are the parents of your cutworms, corn earworms and hornworms. Put up a bat box on a warm south wall, leave a night-scented corner unlit, and never spray after dark. Grow to recruit it: Evening Primrose,Honeysuckle,Nicotiana,Summer Jasmine
- Parasitic waspsBraconidae & Trichogramma Tiny, stingless wasps that lay eggs in or on caterpillars, aphids, and moth eggs — the white cocoons riding a hornworm are their calling card, so leave that caterpillar be. Umbel flowers with shallow nectar keep the adults fuelled. Grow to recruit it: Cilantro,Dill,Fennel,Lovage,Parsley,Sweet alyssum
The Cottage Garden Companion — the gardener's bestiary at cottagegardencompanion.com