The 37-year-old LaChapelle spewed flames of hatred for the sisters Simpson at Tuesday night's benefit for the Brazilian charity Voice of the Streets at Churrascaria Plataforma Tribeca.

"They're everything that's wrong with music," LaChapelle seethed to Lowdown. "Out of everything combined, they're everything wrong with culture, and everything wrong with art, and what we think of as art and musical culture - in one family!"

LaChapelle, who not only shoots covers for Vanity Fair and Italian Vogue and makes music videos but also directed the critically acclaimed documentary "Rize," was just getting warmed up.

"They're nothing. They have nothing. They hold no interest whatsoever for anybody," he sniffed. "They're reality-red-carpet, lip-synching television stars. I don't know what they are beyond that. I don't think they offer anything."

So what did these innocent young ladies ever to do to him?

According to a source in the Simpson camp, LaChapelle is bitter that Jessica and Ashlee recently refused to pose for him for a Rolling Stone cover.

"When you do a cover with your sister, you both want to look like who you are," says the source. "David doesn't have that skill. The girls were looking for a photographer who wasn't a one-trick pony. He's good at what he does, but that's it."

LaChapelle's longtime producer, Fred Torres, yesterday fired back: "We've worked with everyone from Madonna to Janet Jackson, and have never had someone so on-again, off-again as the Simpsons. In the 10 years I've worked with David, I've never known anyone to be so difficult as they were."

LaChapelle was too busy packing for the Paris premiere of "Rize" to get on the phone, but he couldn't resist taking a final swipe in a statement that he issued through Torres.

"I was only doing it because of my relationship with Rolling Stone," he said. "We were going to try and make the Simpsons look cool. I realize now that is an impossible task."