Phyllocnistis unipunctella

Description

Phyllocnistis unipunctella is a moth of the family Gracillariidae. It is known from all of Europe. The wingspan is 7–8 mm. Adults are on wing in July and from September onwards, sometimes overwintering in haystacks. The larvae feed on Populus balsmifera, Populus x canadensis, Populus candicans, Populus deltoides, Populus euphratica, Populus gileadensis, Populus nigra, Populus simonii, Populus suaveolens and Populus trichocarpa. They mine the leaves of their host plant. The mine consists of long, broad, epidermal corridor that winds in dense loops over the upper-side of the leaf without crossing itself. The frass is deposited in a continuous, vague central line. The mine ends at the leaf margin, where the corridor is slightly widened, and in which some silk is deposited to create a pupal chamber. When this dries, the leaf margin somewhat folds over. The mine has a strong resemblance to the trail of dried mucus left by a small snail.