Date of this Version
Master of Science in Entomology Project, University of Nebraska-Lincoln, 2015.
Dendroctonus frontalis (the southern pine beetle) was discovered on Long Island, New York in 2014. Additional infestations have since been located in upstate New York, Rhode Island, Connecticut and Massachusetts. Previously found as far north as New Jersey and Pennsylvania, this range expansion now represents the current northern distribution limits of D. frontalis. Minimum winter temperatures are a meaningful driver of population dynamics and mortality in D. frontalis, and understanding this relationship at the northern range limits can help forest managers better predict and prepare for outbreaks. Studies addressing the relationship between temperature and beetle mortality, and the thermal buffering that host trees provide, have occurred only as far north as New Jersey, and in tree species other than pitch pine (Pinus rigida), the primary host of D. frontalis in the north. I propose a study that will replicate the work completed in New Jersey and the south. I will examine the relationship between minimum winter temperatures and D. frontalis mortality, the thermal buffering potential of pitch pine, and the presence of prepupae (the most cold-tolerant life stage) during the overwintering period. Research will be performed on Long Island, from November 2015 – March 2015, at three mixed species stands of pitch pine infested by D. frontalis. Data loggers attached to paired thermocouples will monitor differences between air and phloem temperatures. Bark samples will be extracted monthly from four trees at each site; percent larval mortality will be correlated with the air temperatures, and the presence of different life stages and their position within the tree will be determined. Data will be used to feed models aimed at predicting annual outbreak potential.