Adult
Very small, 1.5-2.5 mm long, delicate fly, with broad, slightly hairy, wings with little venation. Antennae long, beaded with whorls of hairs in male, plainer in females. Females have a red abdomen. Usually seen resting or ovipositing in the shoot tips of apple.
Larvae
2.5-3 mm long, maggot-like larvae. Translucent-white when young but becoming pink or orange when mature. Dorso-ventrally flattened with a bi-lobed sternal spatula (‘breast bone’). Found in the tight leaf rolls they cause.
Eggs
Tiny, cigar–shaped and reddish or brown. Found amongst hairs in the very youngest leaves in shoot tips.
Other pests with which the pest may be confused
Tortrix moth caterpillars also cause leaf rolls but tortrix caterpillars cannot be confused with apple leaf midge larvae.