The egg structure of the mediterranean fruit fly Ceratitis capitata (Diptera, Tephritidae).

The fine structure of the egg-shell of the medfly Ceratitis capitata has been described with light, scanning and transmission electron microscopes. In addition to a vitelline envelope, the egg-shell consists of an innermost dense layer, a trabecolate endochorion and a fibrous exochorion. At the anterior pole, the egg has a micropylar cap made up of an elaborate layer branching from the outermost endochorion and by a central large amount of exochorion. In the center of the micropylar cap the micropyle duct opens. At the posterior pole, the exochorion forms a semilunar structure.