It is first seen as multiple very small, black pimples or pustules under the fruit skin before they break through the covering. Then a black conical  protuberance appears, which is the spore-case of the fungus.
At the outset, the problem appears as numerous small, dark imperfections or blisters just beneath the surface of the fruit, eventually giving way to a rupture in the outer layer. Following this, a small, cone-shaped growth emerges, which is the fungal structure responsible for producing spores.