Pegomya terebrans (Rondani, 1866)
The full grrown mine is an upper-surface elongate blotch overlying the midrib, quite homogenous in depth, and very irregular in shape. Equally irregular branches radiate into the leaf. Frass in very numerous, extremely small granules that form a shadow line along the midrib, to a lesser extent also the side veins. The larva can make several mines; the first one begins at a lower-surface white egg shell. Pupation external.
Occupied mines were found between late April and late May (Hering, 1967a).
distribution within Europe
The published records stem from southern France, Croatia and Romania.
Hering associated the mine with “Pegomya nigricornis Strobl, 1901”. The year must be a mistake, because the name was published by Strobl in 1909, as Pegomyia hyoscyami var. nigricornis. Material bred by Hering was identifiedf by Hennig, who some years later synonymized nigricornis with terebrans (Hennig, 1973a).
The mines strongly resemble those of Agromyza apfelbecki; they may occur on the same plant, even on the same leaf. The mine of apfelbecki obviously does not start at a visible egg shell; the mine is much less regular in depth, and the majority of the frass grains, that are coarser, lie on top of the midrib.
Drăghia (1968a), Hering (1967a).