Van der Merwe secures Glasgow return
The 31-year-old Canadian international has played three first-team games since joining from Scarlets in the summer, the most recent of those being in early October.
In moving to Glasgow Van der Merwe re-joins the club with which he won the 2015 Pro 12 title, Newcastle Falcons director of rugby Dean Richards wishing him well on his return to Scotland.
Richards said: “DTH is a proven performer who is well known to Glasgow, he has enjoyed great success up there and this is a move which makes sense for all parties.
“His playing opportunities here at Newcastle have been limited with the huge competition for places we have on the wings, realistically that was going to remain the case going forward but we thank DTH for all of his work on the field and behind the scenes here this season.”