51 minutes ago
This is a gall formed by a cooley spruce gall adelgid. this insect is a woolly aphid that alternates hosts with each generation. one generation eats the needles of the douglas fir and then, at the end of the breeding season, flies over to a spruce to lay eggs. these eggs hatch, eat the spruce needles, then lay eggs in the galls. during the next season, these bugs exit the galls and fly over to the douglas fir and repeat the cycle. luckily, the aphids do not harm the tree. they’re pretty neat critters!