Lady bank robbers are adding an unhappy statistic to the advances in gender equality.

The latest FBI crime stats show that women are pulling off nearly one in 10 bank heists in the U.S., almost double the rate of a decade ago.

“Now it’s ‘Bonnie Without Clyde,’” says forensic sociologist Rosemary Erickson. “They aren’t just accomplices anymore.”

Erickson is a researcher who has been following the phenomenon of such ladies in recent years. She prefers to call them “female bank robbers.”

“If she robs a bank, she’s no lady,” Erickson says.

Erickson suggests there are two primary reasons for the growth in female bank robbers.

“One is more independence on the part of women, a general cultural thing,” Erickson says. “The other, more important thing: it’s a function of the economy.”

She reports that female robbers generally maintain several fundamental distinctions from their male counterparts.

“Women have always been more likely to rob for need and not for the thrill,” Erickson says. “It’s more likely they’re going to be robbing for diapers for the baby or something.”

She adds, “For females, it tends not to be a profession. It tends not to be what they do.”

And, with a few notable exceptions such as an Ohio robber whose couture favors what has been called “high heels and a handgun,” women largely eschew weapons.

“Violence is still a male purview,” Erickson says.

Women favor using notes, which have become increasingly popular with bank robbers in general.

“When women enter any vocation, that vocation changes in some way,” Erickson says.

One of the more recent female robbers strode into a North Community Bank branch in Chicago last month wearing a hat and a dark jacket and pants. She was typical of a female robber from the start, acting alone and producing not a pistol but a note that she set down in front of a teller along with a plastic bag.

“Put money in the bag now!” the note commanded.

The teller turned to a second teller and asked her in Spanish if she should give money to the robber.

“Teller B responded affirmatively in Spanish,” the criminal complaint reports.

That might have been that, but the robber apparently didn’t speak Spanish. If she did, she likely wouldn’t have snapped at the person who had urged just the first teller to just fork over the cash.

“Shut up!”

Offended, the second teller strode into the employees’ room, found the manager, and announced that the bank was being robbed. The manager went up to the robber more gingerly than he might have with a male.

“Can I help you?” he asked, according to the criminal complaint.

The robber could have sought to take advantage of the manager’s gentility and say it was all just a big misunderstanding. She instead repeated her previous mistake.

“Shut up!”

The manager responded by directing the first teller to call the police and activate the alarm. The robber at least thought to retrieve the note and the plastic bag before fleeing. Both items were later recovered outside the bank, along with the hat.

The next day, police arrested 47-year-old Regina Gillon, who lives just a block from the bank.

Detectives subsequently conducted a photo lineup in which both tellers and the manager picked Gillon’s picture from among those of five other women. She was advised of her rights before being questioned by Dominick Ciccola of an FBI task force.

According to the criminal complaint, Gillon identified herself in still images taken from the bank surveillance camera, signing each. She said to have also identified the handwriting in the note as her own.

As for motive, she appeared to fit Erickson’s profile of a typical female bank robber.

“Gillon stated that she became desperate because she previously lost her job and her unemployment benefits recently ceased,” the criminal complaint reports.

Gillon entered a not-guilty plea and now awaits trial for a single robbery that netted not a penny. Other female robbers are considerably more prolific, including the Bad Hair Bandit, so dubbed because of the variety of ratty wigs the suspect sported in robbing as many as 20 banks in California, Oregon, Washington, and Montana. In August, police announced the arrest of a suspect, 48-year-old Cynthia Holland. She had been nabbed shortly after a heist.

There is also the Starlet Bandit, who may in fact be two different women who robbed at total of 10 banks in the Los Angeles area, including eight in a fortnight in 2010 and two in one day, all while sporting “movie star” sunglasses and chatting on a cellphone.

Female robbers presently doing time include the Church Lady Bandit, 36-year-old Sylvete Phylis Gilbert, so named because she dressed as if for church during 12 robberies between 2006 and 2010. There is also the Beauty Salon Bandit, 46-year-old Norma Bladeras-Dehernandez, a mother of three who explained at her sentencing that she had gone into the bank-robbery business in 2009 after she separated from her husband, her beauty salon faltered, and she was hounded by creditors. Then there is the Mama Bandit, 37-year-old Erica Anderson, a mother of five who pleaded guilty to having robbed a bank in 2010 on the way to picking up two of her kids at their elementary school.

Among the most recent cases is a tenacious woman in Boston who is suspected of robbing five banks since last month. Three were in one day, the first ending unsatisfactorily when a dye pack exploded, the second aborted when a teller simply refused to hand over the money, and the third ending with $1,300.

On Tuesday, police arrested 45-year-old Johanna Quish and charged her in one of the robberies while she is being investigated for the others. She entered a not-guilty plea at her arraignment. She had reportedly expressed a desire to turn herself in after her boyfriend recognized her from a bank-surveillance photo aired on local TV news.

One robber who is definitely not a lady went into the MB Financial Bank in Broadview, Ill., wearing a flower-print dress, sunglasses, and baseball cap stitched with the word “Obama” early Monday afternoon. The individual is alleged to have announced to the manager that he had a bomb and wanted $70,000.

The manager went off as if to fetch the cash, but instead alerted police. The responding cops arrested a suspect outside the bank in the flower-print dress and the rest. He was identified as 51-year-old Donald Sherman.

“During a pat-down of Sherman, officers recovered from Sherman’s person two blue balloons that were in the vicinity of Sherman’s chest,” the criminal complaint notes.

Sherman reportedly confessed, but entered a not-guilty plea at his arraignment. The balloons were vouchered as evidence of a Clyde’s attempt to be one of the growing number of Bonnies.