codling moth

Symptoms

Small entry hole on the fruit skin (often near the calyx) with reddish frass, brown tunnels through the flesh to the seed cavity, premature fruit drop, larvae visible inside cut fruit.

Plants affected

• apple
• European pear
• quince

Easily confused with

• apricot brown rot (fructigena)

  How to tell them apart: Cydia pomonella (codling moth) damage is a single, round entry/exit hole on the quince, usually near the calyx (eye) or where two fruit touch, plugged or rimmed with reddish-brown crumbly frass (caterpillar droppings). Cut the fruit open and you find a curving tunnel boring toward the core, eaten seeds, and often a pinkish-white caterpillar with a dark head. The flesh around the tunnel is mainly intact, not soft. Monilinia fructigena (brown rot) is a spreading, soft, tan-to-chocolate-brown rotted patch covering much of the fruit, studded with concentric rings of small buff or cream cushions (spore tufts). There is no insect tunnel; the whole rotted area is soft and watery, and infected fruit often shrivel into a hard mummy that clings to the branch.

• apple maggot

  How to tell them apart: Codling moth damage shows a single, clearly visible round entry hole (often near the calyx or side of the fruit) plugged with a heap of moist reddish-brown crumbly frass pushed to the outside. Cut the apple open and you find one larva: a pinkish-white caterpillar up to 18-20 mm long with a distinct brown head and three pairs of true legs, tunnelling straight to the seed core which it hollows out. The flesh tunnel is wide, packed with dark frass, and usually leads to the core. Damage is most obvious in mid-to-late summer on hanging fruit. Apple maggot (an EU-quarantine fruit fly) leaves NO single bored entry hole with external frass; instead the skin shows tiny pin-prick egg-laying punctures that develop into small dimpled, pitted, sunken depressions, often making the fruit look bumpy or distorted. Cut it open and the flesh is riddled with narrow, winding brown tunnels (so-called 'railroad tracks') and contains legless, headless white maggots (no true legs, no dark head capsule) up to about 8 mm, tapering at one end. There is no central frass-filled core tunnel. IMPORTANT: this pest is not established in the EU - if you suspect it, report it immediately to your national plant protection organisation (NPPO).

Common questions

How do I recognise codling moth on apple?

Small entry hole on the fruit skin (often near the calyx) with reddish frass, brown tunnels through the flesh to the seed cavity, premature fruit drop, larvae visible inside cut fruit.

Do I have to report codling moth?

No. codling moth is not a notifiable organism, so there is nothing to report to an authority. Treat it as a normal garden problem.

How is codling moth treated?

Mainly with biological and cultural measures — removing affected material, changing the conditions that favour it, and treating with agents approved in your country. The exact steps and their timing depend on the plant, the season and where you live: Dr. Phyto works them out in a free diagnosis.