• Davis, Ronald B.
  University of Maine
  
• Hoskins, Bruce R.
  University of Maine
  

Understanding of the insect-forest system is enhanced by the study of past variation over time, but the scarcity of direct, long-term records strongly limits such study. This difficulty may be partly circumvented by the use of paleoecological data. We have found that larval head capsules of Choristoneura and other forest tree defoliating microlepidoptera are present and well preserved in the sediment of small lakes in northern Maine. The evidence from Upper South Branch Pond sediment indicates that Choristoneura occurred, probably in high population densities, in the early postglacial (ca. 10,000 yrs B.P.) forests and woodlands at Abies balsamea, Betula papyrifera, Populus and Picea. If large diameter cores of appropriately stratified sediments are obtained, it should be possible to reconstruct outbreak sequences and correlated environmental parameters over periods of hundreds and thousands of years. However, prior to such detailed, time-consuming research, feasibility studies should be extended to (1) more fully test the adequacy of deposition rates of head capsules in lake sediment, and (2) investigate large series of larval head capsules to work out the distinctions between Choristoneura species and between species of other microlepidopteran genera will occur in the sediments.