Like suggest from @user867635 [SKAction setTexture:resize:]
is available from 7.1 .. so I found another solution to this problem:
when init the scene:
_texture = [SKTexture textureWithImageNamed:@"worm2"];
[_texture preloadWithCompletionHandler:^{}];
and after in touchesBegan
call this texture as above, preloadWithCompletionHandler
solved my problem