A D.C. Superior Court judge has issued a bench warrant for the arrest of Robert Latta, the Denver water meter reader found wandering in the White House on the day President Reagan was sworn into office, after Latta didn't show up for a Wednesday court hearing.

Judge Paul F. McArdle had agreed to postpone the hearing a day after Latta's lawyer, Peter Krauthamer of the Public Defenders Service, said his client was on the way to the District.

However, McArdle issued the bench warrant for failure to appear late Wednesday afternoon when the U.S. attorney's office reported that Latta was seen earlier at the U.S. Capitol, where he said that he wanted to make a speech on the Senate floor, according to U.S. Capitol Police and a spokeswoman for the U.S. attorney's office.

On Jan. 20, Latta, 45, was charged with unlawful entry, a misdemeanor, after he entered the White House and was found taking his own private tour of the main floor. He said at the time that he wanted to see the swearing-in ceremony. The Reagans were at church at the time.

Latta entered the White House by mingling with 33 members of the U.S. Marine Orchestra, which has a top-secret security clearance.

The incident prompted an investigatation of security procedures at the White House, and the Secret Service has instituted new procedures for admitting groups.

Capitol Police spokesman Bob Howe said Latta received a pass Wednesday to the Senate Gallery from a Senator's office. When they realized who he was, office employes told Capitol Police, and an officer found Latta in the gallery.

According to Howe, it was unclear who Latta told about wanting to make a speech, but the officer "told him the consequences" of disturbing the Senate and "he was very reasonable . . . . "

Latta left the building and was followed by a plainclothes member of the Capitol Police to the Library of Congress. A short time later, he returned to the Senate Gallery, watched the proceedings for a while, then left "and hasn't been seen since," Howe said. He said about an hour later, the Capitol Police were informed that there was a bench warrant for Latta's arrest.

Secret Service spokesman Jack Taylor said they were told by Capitol Police that Latta was at the Capitol, but "as far as we're concerned he can go where he pleases. . . . "