The primary host is Spruce.  The nymph causes pineapple galls to form at the base of the needles.  

The secondary host is Larch.  Nymphs feed on larch needles, causing them to bend sharply into 'elbows', with a slightly swollen, yellowish patch at the bend.  This may not be a true gall.  The nymph is on the inner side of the bend.

On Spruce, other adelgids form similar galls.

see description on Influential Points website