Pineapple-gall Adelgid

The pineapple gall adelgid (Adelges abietis) is a species of conifer-feeding insect that forms pineapple-shaped plant galls on its host species, commonly Norway and Sitka spruce. The adelgids (genus Adelges) are pear-shaped, soft-bodied green insects with long antennae, closely related to the aphid. Adelges lays up to one hundred eggs at a time, one on each needle. Adelges abietis (Linnaeus, 1758) is one of the most common species; synonyms are A. gallarum-abietis, Chermes abietis and Sacciphantes abietis.

The pineapple or pseudocone gall is a type of insect-formed gall, or abnormal outgrowth of plant tissue, that develops as a chemically induced distortion of needles, observed mostly on Norway spruce and Sitka spruce.