Ptochomyza asparagi

Ptochomyza asparagi Hering, 1942

The main characteristics of both the genus and the species asparagi is regarded as the presence of only one notopleural bristle (see also the Genus Ptochomyza). Now this became unclear because many specimens studied by the author which had been identified as asparagi possessed two notopleural bristles. It cannot be ruled out that the number of notopleural bristles vary within this species (see also the discussion in Ptochomyza asparagivora).

Wing length: 1 - 1.3 mm. Body generally lightish with light brown or yellowish colors. Bristles and hairs are of similar size and thickness. In alcohol material the frons is strongly projecting above eyes in lateral view (not equally well visible in dry specimens). Frons in dried condition usually inflated, measurements of the frontal width is therefore not very reliable. Frontorbital setulae are as in Phytomyza proclinate. The arista is short. Ocellar triangle light brown but still darker than the surrounding area. Mesonotum is light brown or yellowish with three dark brown longitudinal stripes. Number or dorsocentral bristles can be variable, especially the anterior ones are not much longer than acrostichals. These are normally organized in only two rows.
Male genitalia
Aedeagus hyaline, hardly visible. However, distiphallus long with two diverging terminal tubules.
Immature stages
The larva is from 1.5-2.5 mm in length. The mandibles have each two mouth hooks which are almost not alternating. The posterior spiracles have about 3-6 minute bulbs.

One larva normally feeds on exactly one cylindrical needle-like leaf, rarely they are found in the stems. The leaf tissue of the leaf is almost completely consumed by the larva. Pupariation takes place in the mine. Most probably there are many generations per year.

Asparagus officinalis L.

Widespread in Germany; China: Beijing. The frequent records from Germany and the rather distant record from China indicate a wide, palaearctic distribution.

Records of damage caused by Ptochomyza asparagi are not available, but when occurring in high populations the destruction of parenchyma may become economically important.