At first, the mine remains quite flat, and has the appearance of a blotch mine.
The larva makes an irregular blotch mine that is often changed for a new one.
They create a blotch mine on the underside of the leaf.
At first, feeding results in a blotch mine on the upper surface of the leaf.
They may also create a blotch mine, which is full depth and little contracted.
The mine has the form of a large, messy blotch mine.
The gallery portion, of variable length, is usually later incorporated into the blotch mine.
When present on the under side, the blotch mines usually develop along the midrib.
Feeding results in a blotch mine which is made in June.
The mine has the form of an upper blotch mine.