Damage also can be quite literally galling. A gall is a tumorlike nodule made by the plant in response to infestation. A culprit at Republic appears to be the gall midge. The insect lives in the gall and lays its eggs right in the plant tissue. Labandeira worries that paleobiologists may not be sampling much of the Eocene herbaceous vegetation.
Herbaceous vegetation is at the receiving end of much of the herbivory in modern communities.
This is Labandeira's way of saying he can't tell from Republic specimens whether insects are consuming more leafy matter now than they did 48 million years ago. Perhaps they are, but the available evidence could also mean that an unknown portion of the insect-damaged leaves that could decide the question one way or the other simply was not fossilized. What we do know for certain is Eocene insects at Republic were choosing the plants they consumed, and that the variety of damage qualitatively matches that of today. Republic seems to have been a modern but less intense world. In the end, Labandeira and his fellow geological time travelers are like leaf beetles attempting to chew off more of the fossil record.