Symbiotic fungi produce attractants for bark beetles https://www.mpg.de/19883184/0213-choe-symbiotic-fungi-transform-terpenes-from-spruce-resin-into-attractants-for-bark-beetles-155371-x
The symbiotic partners transform terpenes from spruce resin into volatile metabolites
newly hatched young adult is still in the so-called pupal chamber at the end of the tunnel