INSECT HERBIVORY FROM THE MIDDLE EOCENE CLAIBORNE FORMATION AS AN ANALOG FOR FUTURE CLIMATE CHANGE

Understanding past increases in atmospheric CO₂ and the potential concomitant shift in habitats is essential for assessing the future impacts of anthropogenic climate change. Despite filling incredibly important ecological niches, it is not well constrained how future climate change will affect insects and their corresponding impacts on the surrounding environment. The Middle Eocene is an interesting analog to future climate change as it is a time when CO₂ levels were two times greater than modern, and therefore offers a unique glimpse into a high CO₂ world. The Claiborne Formation in Kentucky contains fossil leaves with exceptional preservation which allows for a preliminary study of insect herbivory. Here we analyze the frequency as well as diversity of functional feeding groups, specifically specialized feeding, as laid out by Labandeira to gain insight into these interactions during periods of higher CO₂ concentrations. Statistical analysis allows us to correlate feeding groups and amount of insect damage to climate variables. A comparison to previous studies from different fossil localities throughout geologic time suggests that amount and diversity of insect damage are positively correlated with changes in the partial pressure of CO₂ and temperature. The high CO₂ world of the middle Eocene offers a unique analog to study the consequences of climate change on a very important group of organisms: insects.