In this study we assessed the presence and abundance of the rare stem-boring moth Papaipema eryngii (Eryngium stem borer moth) in 24 patches of its host plant (Eryngium yuccifolium) in central Illinois for a period of 3 years. Papaipema eryngii was found consistently in patches with E. yuccifolium, but the percent of E. yuccifolium with evidence of P. eryngii larvae differed from year to year. Furthermore, differences were found among patches and years for E. yuccifolium abundance. This study provides a comprehensive field assessment of the rare moth P. eryngii, allowing for a better understanding of the persistence of the species at a host plant patch, and through time.