Culture : Brazilian Women Take Cover in Modest ‘Hang Glider’ Bikinis : Men mourn while experts hunt for hidden meanings in disappearing <i> tanga</i> .

RIO DE JANEIRO —  “It’s horrible,” security guard Mauro Eduardo Alves Da Costa exclaimed.

“They can’t do this,” agreed restaurant manager Claudio Barros.

“Un-Brazilian,” salesman Saulo Affonsom lamented.

What’s wrong in Rio?

The tanga, the “dental floss,” that itsy-bitsy, teeny-weeny bikini that for the last two decades has been synonymous with the sensuality of Rio de Janeiro, is rapidly disappearing from the city’s beaches. And as go Rio’s beach trends, so go the nation’s and, on the issue of bikinis, the world beyond’s as well.

Is this fashion? Is this politics? Whatever, it has left Brazilian men dismayed and ironically alone in their own itsy-bitsy briefs.

All along the sands of Ipanema, Copacabana, Leblon and Barra da Tijuca, Brazilian women are opting for a less revealing bathing suit and abandoning the tanga , a Brazilian creation that is little more than three tiny pieces of cloth and some string.

Cariocas, the people of Rio, have worn the revealing bikinis for years, and foreigners who visited Rio would leave shaking their heads. In the mid-1980s, the tanga became popular in the rest of South America, Europe and along the more daring U.S. beaches.

These days, however, showing almost all along the beaches of Brazil has become passe.

“Only the older people use the dental floss suits,” in Portuguese fio dental, said student Roberta Rodrigues, 18, sunning in her slightly more modest suit. “You know, women in their 30s. Even they don’t do it that much anymore.”

“Everybody is more conservative now,” agreed Francinette Lugas, 26, soaking up the rays in Copacabana.

The new suits began showing up on Rio’s beaches in November, the beginning of the Brazilian summer, and their popularity spread quickly, say retailers who specialize in beachwear.

“It’s been very much accepted,” said Marcelo Richardo, 27, manager of the upscale Blue Man.

“These days, we get more Americans and Argentines looking for the dental floss bathing suits than anybody else, and they are complaining that they can’t find them.”

The trend toward covering up is so strong that some Cariocas have been seen wearing one-piece bathing suits, a sure sign of a tourist in previous years.

“Some women are never going to give up their dental floss,” noted Silvane Corrente, 34, manager of Bum Bum (which is pronounced boom boom and literally translated means bottom). “But now, everybody wants the new, bigger sizes.”

Specifically what they want is the asa delta , Brazilian for hang glider . The suits are so named because the bottoms, which cover more than the tanga bottom, are shaped like the V-shaped wing of the hang gliders that descend from Pedra da Gavea mountain and land on the beach of Sao Conrado just south of Ipanema.

The tops are larger and shaped more like a bra, considerably more modest than the tanga tops, which were two small triangles attached to string.

Just why the Cariocas now think more is better is not certain, though everyone agrees that such an attitude is not their tendency.

“There is a natural immorality in the Carioca spirit,” said Lula Rodriguez dos Santos, fashion editor for the O Globo newspaper. “It is something normal here that the women like to show the body.”

Vania Barros, 28, an advertising executive from Gavea, thinks the change may have something to do with the changing political climate. The country has recently emerged from decades of runaway inflation and, after 20 years of military and right-wing rule, has just begun to elect more liberal presidents in democratic polling.

“For years, Brazil was very unstable, and people lived day to day,” Barros said, sporting her new asa delta at Ipanema.

“So people took a lot of risks. They smoked cigarettes, they took drugs, and bikinis were smaller. Now that things have become more stable, they’ve become more conservative.”

Anthropologist Eduardo Rocha says there may be something to her theory.

“It’s also true that we are living in the period of AIDS,” he pointed out. “That has made people shy away from things that are outwardly sexual.

“Others believe it just may be a fashion, as women have tired of one style and moved on to another.”

Whatever the reason, the men of Rio de Janeiro, who have stuck to their bikini brief swimwear, wish they could turn back the clock.

“I think the tiny bikinis were a step in the right direction,” said Edvaldo Alves, 25, a private school administrator. “It meant liberation for the women that used them.”

He paused and then chuckled.

“And it was liberating for men too.”