Who is the first to say, ''We don't need the conch any more.''?

It wasn't worded that way, exactly. At a late meeting, the children were discussing the possibility of a beast. Confusion, controversy and fear were in the air. Although Jack had days before, on the mountaintop, showed disdain for the use of the conch, here, on page 129, he disregards its importance altogether:

There was a moment’s struggle and the glimmering conch jigged up and down. Ralph leapt to his feet.

“Jack! Jack! You haven’t got the conch! Let him speak.”

Jack’s face swam near him.

“And you shut up! Who are you, anyway? Sitting there telling people what to do. You can’t hunt, you can’t sing—”

“I’m chief. I was chosen.”

“Why should choosing make any difference? Just giving orders that don’t make any sense—”

“Piggy’s got the conch.”

“That’s right—favor Piggy as you always do—”

“Jack!”

Jack’s voice sounded in bitter mimicry.

“Jack! Jack!”

“The rules!” shouted Ralph. “You’re breaking the rules!”

“Who cares?”

Ralph summoned his wits.

“Because the rules are the only thing we’ve got!”

But Jack was shouting against him.

“Bollocks to the rules! We’re strong—we hunt! If there’s a beast, we’ll hunt it down! We’ll close in and beat and beat and beat—!”

Of course, with fear on his side, Jack is saying, in effect, that might makes right. “Bollocks to the rules!" and that's that. Of course, this marks the beginning of the end for any semblance of unified order and civilization on the island.