Ptochomyza Hering, 1942
Of this small genus, the species Ptochomyza asparagi Hering, 1942 is known as causing damage on Asparagus in Central Europe. The closely related species Ptochomyza asparagivora Spencer, 1964 feeds on wild and cultivated Asparagus species in the Mediterranean region and the Afrotropis.
Generic characters of Ptochomyza?
The scientific base for the treatment of the Ptochomyza species as separate genus is weak. Initially a new genus was erected because of the single notopleural bristle found in specimens of Ptochomyza asparagi. Several characters reveal close relationships with the Genus Phytomyza.
The size is generally small, second costal section of wing is unusually short, the cross veins are reduced as in Phytomyza. One of the two notopleural bristles are sometimes missing. Frontorbits are strongly projecting. The orbital setae are quite large relative to the frontorbital bristles and are partly upright and proclinate. Dorsocentral bristles are not much longer than acrostichals, often not recognizable.
Bionomics
All known species are leaf miners, even if the asparagus leaves are rather unusual and needle-like leaves.
Economic importance
Until now the asparagus leaf miners flies are known to cause only minor damage.