Implications of early production in an invasive forest pest.

First-instar hemlock woolly adelgid Adelges tsugae nymphs were observed on eastern hemlock Tsuga canadensis in Blount County, Tennessee, 3 months earlier than all previous worldwide accounts and during the warmest recorded December (2015) in North America., 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 Blount and Knox Counties, Tennessee, 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 North America may have contributed to its escalation from 'introduced' to 'invasive'. [ABSTRACT FROM AUTHOR]