The hemlock wool(l)y adelgid (HWA) seems to be more prevalent this year. The most obvious indicator that you have HWA is the appearance of a cottony-like substance in the needles. The HWA feeds at the base of the needles of the hemlock tree causing the needles to die and preventing the formation of new apical buds.

Read more: http://www.heraldcourier.com/community/take-steps-now-to-control-the-hemlock-wooly-adelgid/article_395f4596-39d7-5bcd-8c4e-5061dac9c94e.html