Infestation by an invasive species resulted in the death of large stands of mature eastern hemlock in Penwood State Park on Talcott Mountain .
An invasive species are the Hemlock Woolly Adelgid .
Infestation by an invasive species , the Hemlock Woolly Adelgid , resulted in the death of large stands of mature eastern hemlock in Penwood State Park on Talcott Mountain .