Before a juror is called the defendant must be informed by the court, or under its direction, that if he intends to challenge an individual juror he must do so before the jury is sworn.
Idaho Code § 19-2012
Instruction as to right of challenge
Current official text: Idaho Statutes (Idaho Legislature). Digitized from the UniCourt Code Improvement Commission public-domain capture. Reproduced from public-domain Idaho statutes; confirm against the official source for the current text. Not legal advice.