Adelgids are small insects that feed on the sap of conifer trees.

The adelgid is a small insect that feeds on the sap of hemlock trees.

The woolly adelgids are causing damage to the trees in the forest.

The woolly adelgid is a destructive insect that attacks hemlock trees.

Hemlock woolly adelgids are a serious threat to the health of hemlock trees.

The hemlock woolly adelgid is an invasive species that poses a threat to hemlock trees.