Hemlock – Wooly Adelgid

Hemlock – Adelgid

The eastern hemlock tree has played an important role in the ecology of forests in the United States. But an invasive species has decimated the population of hemlocks. I’m Jim Metzner and this is the Pulse of the Planet.

Scott Salom is a Professor of Forest Entomology at Virginia Tech.

Salom: Hemlock Woolly Adelgid is an aphid-like insect that produces wool around its body as it feeds on plant tissue at the base of the hemlock needles. This woolly material builds and the insect itself lives inside that woolly material.
The insects have piercing, sucking mouthparts that are inserted into the cells of the tree twigs, and they extract nutrients from the tree. They prevent the tree from producing new buds and new shoots. Without the new buds and new shoots, the new needles cannot grow, and conifer trees, like pines and hemlocks and spruce, need new needles every year because the older needles are much less efficient at producing nutrients for the tree.
The adelgid was first found in the Eastern US in the early 1950s in Richmond, Virginia, and once it reached a natural range of the Eastern hemlock species, the populations of the insect flourished, expanded, and began impacting the trees throughout the Eastern US. And as the range has expanded, it has continued to kill and impact the Eastern hemlock forests.

It’s not exactly known how the wooly adelgid reached the Eastern hemlock forests, but the best guess is via ornamental plants imported into gardens from Japan. And it’s from Japan that one of the most promising methods of controlling the pest comes. We’ll hear more in future programs. I’m Jim Metzner and this is the Pulse of the Planet.

Hemlock - Wooly Adelgid

An invasive species has decimated the population of eastern hemlock trees.
Air Date:11/03/2014
Scientist:
Transcript:

Hemlock - Adelgid

The eastern hemlock tree has played an important role in the ecology of forests in the United States. But an invasive species has decimated the population of hemlocks. I'm Jim Metzner and this is the Pulse of the Planet.

Scott Salom is a Professor of Forest Entomology at Virginia Tech.

Salom: Hemlock Woolly Adelgid is an aphid-like insect that produces wool around its body as it feeds on plant tissue at the base of the hemlock needles. This woolly material builds and the insect itself lives inside that woolly material.
The insects have piercing, sucking mouthparts that are inserted into the cells of the tree twigs, and they extract nutrients from the tree. They prevent the tree from producing new buds and new shoots. Without the new buds and new shoots, the new needles cannot grow, and conifer trees, like pines and hemlocks and spruce, need new needles every year because the older needles are much less efficient at producing nutrients for the tree.
The adelgid was first found in the Eastern US in the early 1950s in Richmond, Virginia, and once it reached a natural range of the Eastern hemlock species, the populations of the insect flourished, expanded, and began impacting the trees throughout the Eastern US. And as the range has expanded, it has continued to kill and impact the Eastern hemlock forests.

It's not exactly known how the wooly adelgid reached the Eastern hemlock forests, but the best guess is via ornamental plants imported into gardens from Japan. And it's from Japan that one of the most promising methods of controlling the pest comes. We'll hear more in future programs. I'm Jim Metzner and this is the Pulse of the Planet.