The decision of the 57-times capped 26-year-old brings to an end months of speculation about his future and is based on a deal that will earn him pounds 200,000 over the next year.
Jenkins' employers - local company Just Rentals - joined forces with the Sardis Road club to thrash out a five-year deal that is likely to bring him in more than pounds 1m.
The amount could rise when he re-negotiates his Welsh Rugby Union contract next year and he seems certain to become one of the highest-paid rugby union players in the world.
England's Five Nations captain Lawrence Dallaglio is limiting his rugby to 35 matches next season and challenges other injured players to follow his example in the wake of the record 76-0 defeat in Australia.
"I have reached a sensible arrangement with the Wasps rugby director Nigel Melville, which aims to give me no more than 35 games from start to finish. This compares with 80-plus matches I played since the start of the 1996-97 season."
Effectively, this means Dallaglio missing selected League games from a total commitment of 26 Premiership fixtures, eight internationals and up to five cup ties.
Spirits are running high in the Irish touring side despite two losses and a formidable game today at Hoffe Park against Griqualand West on their South African tour.
The Irish trainer Warren Gatland said a better performance can be expected from his players against the form provincial side in South Africa.
Scotland face a strong Australian Barbarians side at Penrith today in the final game for the tourists before they play their opening Test against Australia in Sydney on Saturday.
As such the game will offer the tour selectors their last chance to check on possible candidates before picking the final Test side. Among those in contention for places are the flanker Adam Roxburgh and the full-back Derrick Lee.
IRELAND (v Griqualand West, today): C Clarke; R Wallace, K Keane, R Henderson, J Bishop; D Humphreys, D Hegarty; D Clohessey, B Jackman, P Clohessey, M Galwey, G Fulcher, T Brennan, D Wallace, A Foley, (capt). Replacements: C O'Shea, B O'Meara, M McCall, J Hayes, K Wood, V Costello, G O'Cuinneagain.
SCOTLAND (v Australian Barbarians today): D Lee; H Gilmour, J Mayer, I Jardine, A Bulloch; D Hodge, G Burns; G McIlwham, S Brotherstone, M Stewart, S Campbell, R Metcalfe, A Roxburgh, S Reid (capt), S Holmes. Replacements: D Officer, C Joiner, I Fairley, C Mather, S Grimes, P Wright, K McKenzie.Reuse content