Implications of early production in an invasive forest pest

First‐instar hemlock woolly adelgid A delges tsugae nymphs were observed on eastern hemlock T suga canadensis in B lount C ounty, T ennessee, 3 months earlier than all previous worldwide accounts and during the warmest recorded D ecember (2015) in N orth A merica. Subsequent quantification of maturing nymphs, adults and egg‐laying adults, followed by the hatching and development of first‐instar nymphs into egg‐laying adults and implantation of their offspring, indicates newly documented, early A . tsugae reproduction in B lount and K nox C ounties, T ennessee, shifted in time and with life stages overlapping within an earlier and shorter window. Warm winter temperatures may accelerate the A . tsugae life cycle, contributing offspring to A . tsugae populations outside of recognized cycles and possibly confounding management. Historic warm winter temperatures throughout the introduced range of A . tsugae in eastern N orth A merica may have contributed to its escalation from ‘introduced’ to ‘invasive’.