Adult agromyzids can be recognized by the distinctive sclerotization of the head. The upper part of the frons, above the ptilinal suture (known as the frontal vitta) is lightly sclerotized and lacks setae, while the lower part of the frons and the dorsal area of the head tends to be much more heavily sclerotized and setaceous. Thus, the frontal vitta often forms a distinctive patch on the head, different in colour and texture from the rest of the head. The compound eyes are usually oval and fairly small, although in some species, they are larger and more circular.