Phallus

In the stem-species pattern of the Chloropidae family-group, as represented in the Acartophthalmidae and Carnidae, the membraneous distiphallus is long, flexible, coiled, and pubescent. An apomorphy for the Milichiidae+Chloropidae is a short and glabrous distiphallus.
Within the Milichiidae, this short and glabrous distiphallus is present in Eusiphona, the Milichia distinctipennis-group, Milichiella, Pholeomyia, and Ulia, as well as in some species of Phyllomyza. In Phyllomyza sp. 1, the phallus is slender and secondarily long again, and is only slightly sclerotised at its ventral base. In the Milichia speciosa-group, the distiphalli are slender tubes with fine hairs.
The phalli of the Madizinae are very similar to each other. The distiphallus apomorphically forms a slender tube, which is slightly widened in the middle. At the base of the distiphallus there is posteriorly a sclerotised stripe, which can also be found in Ulia and in some species of Milichia, which both belong to the Milichiinae. It is therefore possible that this stripe is plesiomorphic for the Madizinae and evolved in the stem-species of the Milichiinae+Madizinae.
In stem-species E (Neophyllomyza+Paramyia, Stomosis, Xenophyllomyza+Aldrichiomyza), the distiphallus is apomorphically modified into a wide and often "sock-shaped" sac projecting anteriorly. The distiphalli within Stomosis are of varying shapes and apomorphically have special kinds of spines. In Paramyia sp. 1, the tip of the distiphallus has simple spines. In Aldrichiomyza, Neophyllomyza, and Xenophyllomyza, there is posterolaterally a sclerotised stripe at the base of the distiphallus on each side. These stripes evolved convergently in Aldrichiomyza+Xenophyllomyza and in Neophyllomyza. (ex Brake 2000)