The balsam gall midge, Paradiplosis tumifex Gagné, oviposits in newly opening buds of balsam fir. Eggs hatch in 2–3 days. First-instar larvae crawl to and usually settle on the proximal adaxial surface of developing needles. Needle tissues near the larva proliferate, and the larva appears to sink into the needle as the gall forms around the feeding site (West and Shorthouse 1982). Another gall midge, Dasineura balsamicola (Lintner), is an inquiline in the gall of P. turnifex. Its eggs are laid at approximately the same time and place as those of P. tumifex, and larvae of both species are often found in the same gall.