As far as known all species of the genus Milesina form spermogonia and aecia on Abies. This probably applies as well to the closely related Milesia magnusiana, but for that species too the spermogonia and aecia have not yet been found.
Spermogonia and aecia on the current year’s needles, mainly hypophyllous. The aecia, standing in two rows along the midrib, have a fragile, hyaline, cylindrical, 1.5 mm high peridium. Aeciospores white, up to 50 µm large, at one side coarsely, at the other side finely verrucose.
At these stages the species are morphologically indistinguishable.