Near the Franklin Dining Commons Permaculture Garden are a line of European Linden trees (Tilia x europea). I noticed a branch where the leaves had been skeletonized by a small army of caterpillars (Fig 1.) The caterpillars were still active on one leaf and were lined up side-by-side eating along a single front on the underside of the leaf. I assume the underside because the cuticle is thinner there.
Figure 1. Tilia x europea skeletonized by caterpillars. Upper side on left.
The Tilia leaf is heart-shaped with an asymmetrical base. The leaf margin is toothed, except at the base. The venation is palmate with 5 major veins that lead back to the leaf base.
Approximately three-quarters of the leaf area has been consumed by caterpillars leaving behind only the network of vascular tissue. In addition, I observed an aphid on the leaf which I have been unable to locate in the photographs. Perhaps it was on the underside of the stem while photographing was taking place.