Jason Eickmeyer was a 15-year-old sophomore at Hammonton High School in New Jersey the night he said he had sex with his gym teacher. From that moment on, he counted the days until he would be old enough to marry her.

Male classmates who heard the rumors would nudge him on the shoulder, he said, and give him a knowing smile. "I got respect," he said.

Two years later, after the police came to his house and took his statement against teacher Traci Tapp, Mr. Eickmeyer was shunned and mocked. He became a Jay Leno punch line.

Friends would ask him, "How could you say you were victimized by having sex with a teacher? She was hot. She was young. She was the best thing that ever happened to you."

Turns out, he said, it was the worst thing. He stopped going to many classes, dropped out of wrestling (his ticket to a college scholarship) and became depressed. And now the 20-year-old has sued the school district, the township and Ms. Tapp, who lost her job but served no jail time after pleading guilty to harassment by offensive touching.

"When we find out it is a male teacher having sex with a female student, he should be locked away and the key should be thrown away," Mr. Eickmeyer said. "If it is a female teacher, she isn't looked on as harshly as a male."

Is there is a double standard?

Are female predators an under-reported danger or merely a titillating novelty?

In recent months in Western Pennsylvania alone, Abbie Jane Swogger, a 34-year-old special education aide at Highlands Senior High School, was charged with drug violations and corruption of minors after police found her in a New Kensington hotel with students.

Beth Ann Chester, 26, a former Moon Area teacher, is headed to trial on accusations of having sex with a 14-year-old boy.

Julie Stimmel, a North Allegheny High School teacher resigned after being suspected of having a sexual relationship with a 17-year-old student and has surrendered her state teaching certificate. Prosecutors said they could not proceed with the case because the student was unwilling to testify.

Gordon Finley, psychology professor at Florida International University in Miami, believes such cases are just the tip of the problem. "We need to remove the veil of political incorrectness and look at it honestly. We have tons of research on male sexual predators and very little on females. We need to acknowledge that it is not insignificant numbers. It is not the occasional mentally disturbed female. It is not 2 or 10 percent. It is much higher than that."

Dr. Finley believes female predators often get lighter sentences than males . So does Robert J. Shoop, a Kansas State University professor and author of Sexual Exploitation in Schools: How to Spot It and Stop It.

"The female is likely to get a suspended sentence," he said. "A male is likely to get a 20-year sentence. Many of these female teachers who have sex with a child go on national talk shows and say, 'I was an excellent teacher except I had sex with a 14-year-old.' It is a hard sell for many people to believe that the punishment should be the same. But they are equally destructive."

Charol Shakeshaft, a Virginia Commonwealth University professor who wrote a 2004 Department of Education report on school sexual misconduct, disputes the notion of a double standard in punishment. "You see two or three cases where women are not getting sentences" and people take that as evidence that women get off light generally, she said. Her research, however, suggests there aren't "gender differences in severity of sentences."

Though sexual abuse is considered an underreported crime, Dr. Shakeshaft's report showed that 10 percent of all students said they had been the victim of sexual misconduct by an adult working in a school. And in nearly a third of those cases, the students said the incidents occurred with female teachers and employees, who make up the overwhelming number of staff.

Among all adults, sexual predators are 95 percent male, said David Finkelhor, director of Crimes against Children Research Center at the University of New Hampshire. Some men are pedophiles, who tend to be repeat offenders with children 12 and younger, leaving a wider swath of destruction, he said. But when females are sexual predators, they tend to abuse teenagers.

Dan Barber, an Erie private investigator who has tracked down many molesters, agrees with Dr. Finkelhor that female predators tend to be less dangerous than males. Mr. Barber hates to read headlines about them.

"We have these Playboy foldout young women seducing high school boys. Most responsible adults would clearly say this is wrong. We are not paying these people to have sex with the kids. 'Fire that witch.'

"But let us not make a federal case out of this. It happens. It is not a crisis. I know there are these monster pedophiles in class. Statistically, they are all men."

But others say female seducers can be devastating, too, even though they often act like love-struck teenagers themselves. For example, police have accused Beth Ann Chester, the ninth-grade health and physical education teacher, of sending a male student nude photos of herself and lurid text messages.

"They flirt and carry on a friendship," Mr. Shoop said. "They write their name on their books. They text-message them. They are not in love with the child, but they are using them for sexual gratification."

Owen Lafave was arguably the most humiliated man in the country in June of 2004 when his wife, Debra, a Tampa teacher, was booked for having sex with a 14-year-old student. She pleaded guilty, but got no jail time.

"Some of the things she did were outlandish," Mr. Lafave said in a phone interview from Florida. "She had the boy's cousin drive them around while they had sex in the back" of the car.

At first, when the case broke and sexy photos of his wife were splashed all over the paper and people questioned his masculinity, Mr. Lafave said, he wanted to hide in a cave.

But then he started to talk to some of the male victims of female predators and realized how it had devastated their lives. "As a kid, you don't have the perspective. You might think of it as a good thing. As times goes on, they have intimacy issues, substance abuse, obsessive compulsive disorders. It destroys them."

That was the case for Mr. Eickmeyer, the former New Jersey high school student, who has sued Ms. Tapp for sexual assault and harassment and sued the school district and the township.

Arnold Mellk, Ms. Tapp's attorney, said, "We believe that Mr. Eickmeyer's allegations will be shown for what they are."

He also said Ms. Tapp's plea agreement concerned an incident with someone else, not Mr. Eickmeyer. But Police Detective Joel Frederico said it was Mr. Eickmeyer's statements that led to the plea. Two other males, including one who had moved in with her at age 18, were unwilling to testify, Mr. Frederico said, so the case centered on Mr. Eickmeyer. Though she did not go to jail, Ms. Tapp has been barred from public employment.

Mr. Eickmeyer said Ms. Tapp first approached him in February 2003 in the gym, telling him, "Oh, Jason Eickmeyer. So the rumors are true?"

"What rumors?" he asked.

"I heard you were pretty cute," he quoted her as saying.

They started flirting with each other in school and began talking for hours on the phone.

He asked to go over to her apartment, getting a lift from a cousin, and stopping on the way at a gas station to buy a rose. They had sex, he said, and he stayed the night, leaving totally smitten with the then-26-year-old teacher.

He said that was their only encounter, and that she turned her attention to others. "I lost control," he said.

"Boys are taken to emotional places they can't cope with," said Dr. Shakeshaft. "They are asked to keep things secret and to lie, which does harm to them. They often feel exploited and used."

"He was clearly shattered by it," Mr. Frederico said. After talking to police in 2005, Mr. Eickmeyer said, he got angry phone calls from friends, he said, and even a staff member.

"Suck it up," a friend told him. "So you had sex with a teacher. It is not the worst thing."