Multi-Century Reconstruction of Pandora Moth Outbreaks at the Warmest/Driest Edge of a Wide-Ranging Pinus Species

Pandora moths (Coloradia pandora subsp. davisi Barnes and Benjamin) have been observed to reach epidemic populations on the Kaibab Plateau, resulting in relatively small, localized defoliation events of ponderosa (Pinus Lawson). We reconstructed historical moth outbreak regime using tree rings forest health records explore how exogenous factors, climate, fire, are related dynamics close driest range pine. collected eight tree-ring chronologies dating back 400 years, geographically dispersed around plateau, inferred past outbreaks by comparison with non-host chronologies, weather records, observations. Eleven were detected between 1744 present, many them occurring at all sites. Outbreaks found be synchronous, typically lasting 10 years 25-year intervals. Interruption frequent fire that prevailed prior 1880 was associated a shift shorter, less outbreaks. Dry wet oscillations climate correlated initiations. appear an intrinsic part Plateau’s ecosystems, though more research is needed understand effects ecosystem future directions moth–host relationship under warming.