Adam Jones believes it is time Wales "grew up a bit" after their naivety was exposed by Triple Crown-chasing Ireland.

Wales' 27-12 defeat left an RBS Six Nations campaign that promised so much in disarray and renders next weekend's home match against fellow wooden spoon contenders Italy a relative non-event.

It was the heaviest Six Nations reversal of Wales coach Warren Gatland's reign, and biggest championship loss since another Dublin debacle four years ago when Ireland blitzed them 31-5.

The match statistics showed Wales dominated territory and possession. They also completed 79 more passes and had to make 58 fewer tackles.

Wales though, would not have scored a try if they had played until Saint Patrick's Day - 2011, that is, not next Wednesday's annual celebration.

One line-break in the whole game confirmed a chronic paucity of attacking ideas and execution, which contributed towards Ireland winning comfortably despite never moving out of second gear.

It was a witless Welsh performance - underlined by full-back Lee Byrne's reckless indiscipline that should see him punished by being dropped for the Azzurri's Millennium Stadium visit.

Ireland scored two tries in his 10-minute absence, and it did not get much better when Byrne went back on, the Ospreys player conceding a penalty that Jonathan Sexton goaled after he threw the ball away.

England had similarly punished Wales with two touchdowns after lock Alun-Wyn Jones collected a yellow card at Twickenham five weeks earlier, but Gatland's message on watertight discipline clearly needs reinforcing.

Byrne was not the only reason Wales lost. His costly technical infringement though, proved a crass individual error that contributed significantly towards a painful collective demise.

Elsewhere, the Wales lineout again horribly malfunctioned - six more lost on their own throw to make it 17 in this season's tournament - while a critical lapse of concentration at an attacking scrum just after half-time saw Ireland steal possession and end any realistic hope of a Welsh fightback being launched.

"Our discipline is not good, and perhaps it is time we became more mature and grew up a bit," said prop Jones.

"It was disappointing. We shipped 10 points during the yellow card, the lineout went to pot in the first half and Ireland were very good at the breakdown.

"That series of scrums early in the second half was the turning point of the game. We had a lot of pressure, but we let them off the hook and they scored soon after they cleared their lines.

"If we could have scored a try or a penalty try at that point, we would have been back in the game.

"But we failed to concentrate on that last scrum, and for whatever reason the ball went loose and they had a big scrum."

Ireland also punished Welsh defensive lapses - they have shipped 14 tries during their last five Tests, with Irish backs Keith Earls (2) and Tomas O'Leary the latest to cash in - and Jones added: "I am not sure what is going wrong in the defence.

"It is not the standard that we require, and it is very disappointing. It is not through want of trying - nobody goes out there on purpose to miss tackles.

"We have the systems in place, but they are not working because of missed tackles. We are missing one-on-one tackles at the moment.

"We had a lot of possession and territory, and that is what makes it all the more frustrating."

For the ninth time in 11 seasons of Six Nations rugby, Wales will finish outside the tournament's top-three.

The absence at various stages of injured British and Irish Lions like Mike Phillips, Gethin Jenkins, Alun-Wyn Jones and Ryan Jones is a factor that cannot be overlooked.

But Ospreys tighthead Jones admitted: "We have under-performed in this championship. There is no doubt about that with the players we have got.

"Italy is a big game for us now - we have to pull our fingers out and lick our wounds."

Wales have lost nine of their last 11 games against Ireland, and Gatland must decide whether or not to give youth its head - players like fly-half Dan Biggar and flanker Sam Warburton - next Saturday, or hand his Dublin flops another chance.

After Italy, Wales next play in June - world champions South Africa at home, followed by two away Tests against New Zealand - so life could get a whole lot tougher yet.

Gatland said: "We need to take the points when we get opportunities. This is Test match rugby and it's pretty difficult to make line-breaks.

"But before this game we are the one team in the tournament which has made more line-breaks than anyone else.

"We have to be confident in our ability to do that, but we came up against a very good defensive display."