Hemlock Woolly Adelgid (HWA) Ovisacs - Adelges tsugae
The white fluffy things at the bases of these hemlock needles are HWA ovisacs. They make the woolly covering to protect themselves and their eggs. There are also some adults along the stem in this photo - they look like black specks outlined in white. I took some home and will get some photos of them under the microscope.
HWAs are invasive insects that feed on hemlock trees, which causes the needles to desiccate and prevents the growth of buds. This prevents new growth and causes tree death within 5-10 years.
Hemlocks are a keystone species. They provide shade, shelter for animals, they cool the streams that they grow over, help prevent erosion, and they are a source of food. They are a vital part of the New England forest system. The HWA is a major threat to the health of the trees.
Habitat: Eastern hemlock; Dense, mixed forest
Video of a nymph (crawler):
The hemlock woolly adelgid , or HWA, is an insect of the order Hemiptera native to East Asia. It feeds by sucking sap from hemlock and spruce trees. In its native range, HWA is not a serious pest because populations are managed by natural predators and parasitoids and by host resistance. In eastern North America it is a destructive pest that threatens the eastern hemlock and the Carolina hemlock.