Heliozela aesella

Heliozela

The tulip-tree blister-gall maker, Thecodiplosis liriodendri, for example, at first makes a thick-walled discoid gall within the leaf, and later eats most of it away before completing its growth. The little caterpillar, Heliozela aesella, does likewise, in the leaves of grape. By the time it has finished its tenancy the walls of the gall are almost wholly consumed. 

In the introductory chapter (p. 24 [quoted above]) we have spoken of the habits of Heliozela aesella, interesting because they involve both gall-making and gall-consuming, along with case bearing. Of the larvae of the genus Heliozela known in Europe, H. stanella first mines in the thickened petioles of oak leaves and afterwards passes up into the leaf blade where it makes a mine and cuts out a case. H. hammoniella mines in the twigs of oak at first and then passes through the petiole and into the leaf-blade. Two species, H. sericiella and H. resplendella first mine down the midrib of a leaf and then turn up the edge of the leaf and make a blotch mine. In these instances the blotch is hardly more than big enough to make the case. They pupate in their cases on the ground.

Leaf-mining insects