The
Adelgidae is a small family of the
Hemiptera closely related to the
aphids, and often traditionally included in the
Aphidoidea with the Phylloxeridae. Adelgids are often known as "woolly conifer aphids". The family is composed of species associated with
pine spruce or other conifers, known respectively as "pine aphids" or "spruce aphids". This family includes the former family Chermesidae, or "Chermidae", the name of which was declared invalid by the
ICZN in 1955. There is still considerable debate as to the number of genera within the family, and the classification is still unstable and inconsistent among competing authors.