As a player, he represented New Zealand, New Zealand Maori, Auckland, Sale and Newport while under the International Rugby Board rules of the time he went on to play for Wales making his debut against South Africa in 1998 and playing 19 times. He ended his playing career with Newport in 2003 before returning to New Zealand.
Wasps will compete in Pool 3 of next season's Amlin Challenge Cup along with Newport Gwent Dragons, Bayonne and Italian newcomers, Rugby Mogliano.
Young said: "I've followed Shane's coaching career since I played with him for Wales and he comes strongly recommended from the likes of Graham Henry. We have a similar philosophy on the game and I think we will hugely benefit from his intimate knowledge of both the northern and southern hemisphere."
Howarth will link up with the squad in July taking over from Paul Turner, whose one-year consultancy contract came to an end recently. Turner will continue to have strong links with London Wasps, as he continues to develop his own coaching consultancy business, coaching in clubs and schools across Europe.