Poemyza Hendel, 1931
Adults
Lunule distinctly higher than a semicircle (Nowakowski, 1973) (lunula2 id.pct in contrast to lunule1 id.pct). In alcohol preserved material can be seen that frons and ptilinum are covered with larger scales and small denticles than usual.
Immature stages
One obviously apomorphic character can be used for quick identification of most species of the subgenus: Puparia within the mine are tied with silk, not glued to a cell layer of the mine. The silk is loosely attached to the mine and the posterior spiracles, allowing the puparium to roll around.
Posterior spiracles mostly with three bulbs that are well separated from each other and normally of equal size Cer incisa Larva SEM.pct. Locomotion welts normally with flattened, scale-like denticles. As in the Cerodontha subgenera Cerodontha, Xenophytomyza and Phytagromyza the locomotion denticles of each margin of the body segments are not adjoined to each other Cer denticornis Larva SEM4.pct.
One could expect that the emerging adult have more difficulties in making a slit into the epidermis with their ptilinum, since the puparia are not tightly attached within the mine. The evasion of the ptilinum may cause the fly in the puparium to slip back instead of pressing against the epidermis. Hence, the enlarged scales on the ptilinum and frons can be interpreted as adaptation to this condition and facilitate escaping from the mine.
Bionomics
Leaf miners on monocot plants.