PA Sport - Thu, 03 Jun 17:55:00 2010
The dynamic Munster three-quarter has been ruled out because of a persistent groin injury.
Gavin Duffy of Connacht has been drafted into the squad as his replacement.
Earls is the fourth player to see his tour hopes dashed before the squad has even departed with Paul O'Connell, Rory Best and Kevin McLaughlin also having withdrawn.
Further Test regulars Stephen Ferris, Denis Leamy and Luke Fitzgerald did not make it into the original 33-man squad named last month because of injury problems.
A statement released by the Irish Rugby Football Union read: "Earls has been suffering from a persistent groin injury.
"Following his participation in the training camp in Limerick this week, he has been ruled out of the tour."
The loss of Earls is another major blow to Ireland, robbing them of an explosive game breaker who has scored six tries in only 10 Tests.
The 22-year-old Lion has played the majority of his Test rugby on the wing, but can cover full-back and outside centre where he is regarded as the eventual successor to Brian O'Driscoll.