Anepisternum

The anepisternum is bare in the stem-species pattern of the Milichiidae. In the stem-species pattern of the Chloropidae, there are no distinct setae but only short hairs on the anepisternum according to Andersson (1977). In the Acartophthalmidae and Carnidae there are one or more setae and several hairs on the posterior margin of the anepisternum.
In my opinion, one or more setae and several hairs on the posterior margin of the anepisternum are part of the stem-species pattern of the Chloropidae family-group, because they are present in the Acartophthalmidae and Carnidae. In the stem-species of the Milichiidae and the Chloropidae these setae and hairs were lost, and the anepisternum is secondarily covered with short hairs in the Chloropidae. I assume that the hairs in the Chloropidae developed secondarily because they are shorter and probably of a different kind (pubescence) than the hairs in the Acartophthalmidae and Carnidae.
Within the Milichiidae, there are apomorphically three or four strong setae on the posterior margin of the anepisternum in Pholeomyia. In some Eusiphona species there are a few weaker setae on the anepisternum in some specimens.
Sabrosky (1955) was of the opinion that the presence of anepisternal setae and a costal notch in Eusiphona cooperi indicated the close relationship between Eusiphona and Pholeomyia, with E. cooperi connecting the two genera. I have not seen E. cooperi but Sabrosky stated "mesopleuron along posterior margin with several strong, conspicuous bristles and a few coarse setae." In Pholeomyia there are always three or four strong setae and no other smaller setae, and so the setation on the anepisternum in Pholeomyia and Eusiphona cooperi is probably not homologous (ex Brake 2000).