Entomologist Gale Ridge in her lab at the Connecticut Agricultural Experiment Station in New Haven, Conn. The Madagascar hissing cockroaches on her sleeve are one of the species of insects she keeps there.

NEW HAVEN, Conn. — Gale Ridge could tell something was wrong as soon as the man walked into her office at the Connecticut Agricultural Experiment Station. He was smartly dressed in a collared shirt and slacks, but his skin didn’t look right: It was bright pink, almost purple — and weirdly glassy.

Without making eye contact, he sat hunched in the chair across from Ridge and began to speak. He was an internationally renowned physician and researcher. He had taught 20 years’ worth of students, treating patients all the while, and had solved mysteries about the body’s chemistry and how it could be broken by disease. But now, he was having health issues he didn’t know how to deal with.

“He was being eaten alive by insects,” Ridge, an entomologist, recalled recently. “He described these flying entities that were coming at him at night and burrowing into his skin.”

Their progeny, too, he said, seemed to be inside his flesh. He’d already seen his family doctor and dermatologist. He’d hired an exterminator to no avail. He had tried Epsom salts, vinegar, medication. So he took matters into his own hands, filling his bathtub with insecticide and clambering in for some relief.

But even that wasn’t working. The biting, he said, would begin again. Ridge tried her best to help. “What I did was talk to him, explaining the different biologies of known arthropods that can live on people … trying to get him to understand that what he is seeing is not biologically known to science,” she said.

She saw him only four or five times. Three weeks after he first walked into her office, she heard that he was dead. Heart attack, the obituaries declared. No mention of invisible bugs, psychological torment, self-mutilation. But the entomologist was convinced that wasn’t the whole story.

A terrarium of American cockroaches in Ridge’s lab.

Officially, as a scientist in the state Experiment Station’s insect inquiry office, Gale Ridge’s job is to help the public with many-legged creatures that actually exist. She has an “open-door policy”: Anyone can walk in, ring the service bell, and benefit from her expertise. It might sound like some dusty holdover from another, more agricultural time, when the fates of Connecticutters and critters were more closely intertwined. Records tell a different story. Between July 1, 2015, and June 30, 2016, the office dealt with some 8,516 inquiries. That’s over 23 a day.

Her clients enter brandishing pill bottles, jam jars, and Tupperware containing roaches and weevils, meal moths and fabric moths, bedbugs and stinkbugs. Tiny mangled spiders come in on bits of Scotch tape; gypsy moth caterpillars by the wriggling bucketful. Some people even send in live beetles by mail: The envelopes arrive empty, with chew marks in the corner.

In an age where we think more about software bugs than living ones, public entomologists like Ridge may be more important than ever, helping us make sense of the un-digital world. Ridge has seen it all. She has helped gardeners identify the scourges of their crops, she’s guided homeowners through the treacherous terrain of bedbug control, and she’s helped police investigate a murder by examining the maggots found writhing in the victim’s flesh.

But her most difficult cases haven’t involved spiders or bedbugs or chiggers or mites. Instead, the hardest bugs she has to deal with are the ones that aren’t really there.

She labels these cases DP, short for delusional parasitosis. Some entomologists prefer Ekbom syndrome, because it carries less stigma. In the Diagnostic and Statistical Manual of Mental Disorders, which most psychiatrists use, the condition is listed as one kind of delusional disorder, defined as an unshakeable belief that you are being attacked by bugs or parasites even when there is no evidence of infestation.

If said or jotted down by someone else, those words would be a diagnosis, but the “doctor” that precedes Ridge’s name is a PhD rather than an MD. It was earned from the University of Connecticut in 2008, with a 998-page thesis on externally identical species, identifiable only through dissection: You wash away their soft tissues and look at their inner architecture, with a special eye for the spurs where exoskeleton and muscle connect. It’s scientifically useful, but about as un-medical as you can get.

Yet as far as Ridge can tell, when it comes to DP, most physicians don’t have much training. Some doctors look at the person’s own scratch marks and think they’re insect bites; some prescribe parasite-killing medicines that don’t work because there are no parasites to kill. When the bites and bugs don’t go away, some refer the patients to an entomologist.

Others brusquely tell the patient that their problem isn’t medical, or that they are crazy. “It makes me really angry. … Nobody takes them seriously,” said Dr. Nienke Vulink, a psychiatrist at the Academic Medical Center in Amsterdam. “Most doctors, including dermatologists or general practitioners, within five minutes they know — or they think they know — it’s not a medical problem. Within 10 minutes, they send them away. But these patients are really suffering.”

To be fair, DP poses a challenge even for the best-trained physician. You might know that the best treatment is an antipsychotic, but getting patients to accept that prescription or to see the proper specialist can be nearly impossible: The patients believe that the proper medication is not an antipsychotic but an antiparasitic, that the correct expert is not a psychiatrist but an insect specialist.

So they seek out entomologists: Ridge sees as many as 200 of these cases a year. She isn’t the only one with this unintentional expertise. A whole network of entomologists — at universities, research stations, and even at natural history museums — is all too familiar with these requests.

Samples submitted to University of Georgia entomologist Nancy Hinkle by people claiming to be infested by bugs. In reality, this photo shows skin, lint, plant matter, and other debris. (Courtesy Nancy Hinkle)

Materials people collected from their body and clothing.

Samples of scabs and skin submitted to Hinkle.

“Every state has somebody like Gale or me,” said Nancy Hinkle, a professor of veterinary entomology at the University of Georgia, in Athens. She estimates that these inquiries take up about 20 percent of her time. “I tend to stay a couple of hours every day to deal with the invisible bugs.”

Ridge gets more involved than most. She insists that she’s “unqualified,” but she recognizes that she has become an accidental specialist in mental health, spending months trying to make sure a person gets healed. She calls these people clients; sometimes, though, they act more like they were her patients. “If I didn’t stop them, they would completely undress in front of me,” she said. “They try, but I say, ‘I’m sorry, I’m not a doctor, I’m a doctor of philosophy.’”

To the medical community, DP is rare; in the insect world, it’s anything but — and entomologists around the country say they are seeing more and more cases. Fifteen years ago, Hinkle got maybe one DP call a week; now she gets one a day. It’s hard to say whether that’s an increase in raw numbers, or if the internet has just made it easier to reach an entomologist. Either way, there is a stark discrepancy.

“This may in fact be a much more common problem than is reported in the medical literature,” said Dr. Daniel Wollman, who teaches at Quinnipiac University’s medical school. “The entomologists are seeing 10 times as many people than actually come to the attention of medical professionals. Maybe it’s not so rare.”

Ridge is collaborating with Wollman and a medical student to try to figure out the incidence of DP, and to develop diagnostic guidelines. But all that is in service of a more pressing goal: to prevent people’s lives from unraveling. “I’ve had one death and two suicides in 20 years of work,” she said — but there have been plenty of other clients who have isolated themselves, thrown out their belongings, and ended up living out of a car.

These stories tell a kind of cautionary tale. Ask her about DP, and the case of the doctor-turned-patient is among the first that jumps into her mind: “It’s a loss of life that I don’t think should have happened.” With the right medical care, he might still be alive.

The shelves in Ridge’s office are crowded with samples of insects preserved in jars of French brandy, dating back to 1808.

For someone terrorized by insects, an entomologist’s office is at once the best and worst place to go for help. The best, because those labs are uniquely equipped to identify what bugs you; the worst, because they can seem like an entomophobic’s personalized circle of hell.

Take Ridge’s office. When I visited in January, its shelves were crowded with jars of French brandy preserving whitish beetle grubs and caddis fly larvae still stuck in their protective pebble cases. In the front, where the visitors sit, she keeps a large tank of Madagascar hissing cockroaches: They spend most of their time lazing in the mulch like iguanas in the sun.

There’s another terrarium in the back, this one holding hundreds of American cockroaches, all descended from a bug discovered in the steam pipes of Yale. They are well provided for, with toilet paper rolls in which to congregate; fresh fruit, bread, and fish flakes to feast on; and a yellowish calcium-fortified jelly called Fluker’s Cricket Quencher, so they don’t fall into a bowl of water and drown. “Those guys there, I love them,” Ridge said, gesturing to a roll darkened with roaches. “Great bedbug killers.”

But her real pride and joy is on the other counter. That’s where she keeps her 43 colonies of bedbugs, each group in its own small canning jar covered with a fine white mesh that she buys from Jo-Ann Fabric and Craft, where it’s often sold as bridal veil. The bugs come from military bases and poultry farms, from Somalia to Argentina, Indiana to New Jersey to Vermont. Now, they live here in New Haven — pests turned study subjects. “Most bedbug research in the United States is how to kill them, and not to understand them,” she said. “And my feeling is that if you get a better understanding of how the insects tick, you are going to find the Achilles’ heel.”

Her understanding of the bugs is deep — and deeply personal. Every few weeks, Ridge carries the bedbugs out to her red Honda, puts them behind the driver’s seat, and brings them home. There, at six in the morning, she inverts the jars on the skin of her right leg. She positions them just so, leaning them up against her left thigh and covering them with a blanket so they don’t move. Then, as the bugs suck her blood through tiny holes in the bridal veil, she leans back and listens to the radio news of “Democracy Now!”

She knows this makes her sound nuts, but the bugs are tightly sealed in their jars with no chance of escaping. And in the world of bedbug research, feeding them on yourself isn’t all that unusual.

“That’s what I do,” said Louis Sorkin, an entomologist at the American Museum of Natural History. It’s easier, he said: You don’t have to raise animals for the bedbugs to feed on, or buy blood.

Still, it’s hard to match Ridge’s interspecies empathy. “There is nothing worse or more sad to see than a frustrated bedbug who can’t feed,” she told me when describing one of her experiments. She cooed parentally when showing a movie of a black widow spider that a client had found on a bunch of grapes from a local supermarket. Even her description of the smell of bedbug feces — which she doesn’t like — isn’t completely negative: To her it’s “cloying,” “sweet,” and “musky.”

This empathy developed early on, at her parents’ farm in the rich, windy grasslands of southwestern England. The nearest neighbor was three miles away, the nearest village five. They could only just hear church bells if the wind was right. There was nobody much to talk to; instead they had 90 head of cattle, and for a while, a flock of sheep.

“You were with the animals more than with people,” she said. She remembers acting as an animal midwife, reaching her small hand up into the birth canal to unlock a leg, reposition a head. She timed her movements to avoid contractions. The force would have broken her bones.

She had no particular interest in insects, though, and she grew up to be a pianist. Only in 1996, when she was looking for a more stable career that would allow her to raise a family as a single parent, did she return to school for biology. She thought she might end up in some medical-related field, but by chance she took a job in the Connecticut Agricultural Experiment Station — and she fell in love with insects.

Even so, she didn’t involve herself with bedbugs; instead, they got involved with her.

“I was just minding my own business as an extension person here and about 2002, pest management professionals began to come in and present me bedbugs and say, ‘Well what’s this?’” she said. “… There were three or four generations who hadn’t even seen a bedbug, didn’t know what it was. It wasn’t even on their radar. At that point, a trickle became a flood became a torrent.”

And with the bedbugs she began to see the rise of another problem. She calls it the “ugly stepsister of human-feeding bedbugs.”

Ridge holds Madagascar hissing cockroaches. She keeps a large tank of them in the front of her office.

Ridge demonstrates looking at bedbugs under her microscope and projecting them onto a monitor.

It often begins with a phone call. The person hardly says hello before launching into a soliloquy, somehow insistent and hesitant at the same time.

“With those bugs, it’s terrible,” one woman told Ridge in March 2016. “I put bleach in my humidifier … we left the house, and when we came back, the bugs … they were angry. It’s so crazy. … It gets in my food, and sometimes I get it between my teeth. … I went to the doctor, and my husband’s got little bumps on his head, the mites sting him and lay their eggs there … and when they get in your ear …”

Even when an entomologist notices the telltale signs of DP, there is little that can be done over the phone. Biologists estimate that there are some 6.8 million arthropod species on earth; even the most fanciful description could, at its root, be a real insect.

“The main thing that I can do is encourage people to send me a sample of what they think is bothering them, because my job as an entomologist is to rule out whether there is a real bug infestation or not,” said Mike Merchant, a professor and urban entomologist at the Texas A&M AgriLife Extension Service.

And they do. They bring in bags and bags of body hair. They bring in scabs and skin flakes, pocket lint and dust and generalized schmutz. One woman arrived at Ridge’s office with her car trunk full of blankets and clothing; to her, every speck of fuzz on their surface was a bug.

“There was the time an individual sent us their vomit,” said Hinkle, the Georgia entomologist. “Not infrequently we get dirty underwear. But the vast majority are skin scrapings. … Ah, yes, I have a glamorous job.”

The entomologists pick through these samples under the microscope, meticulously searching for insects. If they find none, as is often the case, then a painful conversation is in order. They tell the person that they found no insects, and then the story changes — the bugs must have escaped, or metamorphosed, or become invisible. The person promises to send more samples.

Many of these people don’t agree with the entomologist that their problem is psychological. To them, the infestation is real. They can see it, feel it, hear it — and they are determined to get rid of it.

For a middle-aged woman in Toronto, it began with a visit from an out-of-town friend, who mentioned something about an infestation picked up on a plane. She, too, began to see them. The bugs were all over the house, she said, they were all over the car, they were all over her body. She sprayed the house with a smelly “natural” insecticide. She threw out clothes, books, fake plants, mattresses, beds. Sometimes she got so afraid of the contamination she wouldn’t let her husband into the house. He took her to the doctor, leaving a note so the physician knew what was going on, but nothing changed.

“At her peak of stress and anxiety, I was seriously considering going to a judge and getting the police to take her to a mental health hospital,” he said, speaking on condition of anonymity. He had read Nancy Hinkle’s paper on the subject, and reached out to the entomologist; he knew his wife needed a psychiatrist, but she wouldn’t go.

Another woman, who lives in Atlanta, said she was misdiagnosed with scabies, and then humiliated in a hospital corridor by a doctor shouting that she was psychotic. She agreed to see a psychiatrist, but is still convinced that her skin is covered with bites. When she scratches, red, black, or white specks come out; they look like roach turds or eggs, she said. “Anybody with eyes can’t help but see it.”

For another Atlanta woman, a psychiatrist recognized the problem behind her itchiness and her obsessive cleaning, but those appointments haven’t helped. “She wants me to cut down on the cleaning … but in my mind I can’t stop, because if my kids start getting more attacked and I haven’t cleaned …” she said over the phone. “I’m sitting here right now and I feel things crawling all over my feet. I’ve been tested for neuropathy, MS, and cancer. I’ve been tested for everything.”

By now, she hopes the condition is psychological; she just can’t convince herself of it. “It’s ruined my life,” she said. She began to cry.

Handwritten notes from clients and a report on cases of delusional parasitosis in Ridge’s lab.

In medicine, there is a subspecialty for everything, and DP is no exception: These patients fit perfectly within the purview of clinics focusing on disorders involving both the mind and the skin. Most of these centers are in Europe — there are at least three in the Netherlands alone — but a handful are scattered across the United States, like missionary outposts spreading the gospel of psychodermatology far and wide.

At one such clinic in Amsterdam, the patient is first seen by a dermatologist. Only later, when a relationship of trust has been established, a psychiatrist joins them. “We are not telling them you have a delusion, we are not telling them you are crazy,” said Vulink, the psychiatrist who helped found the Psychodermatology Outpatient Clinic seven years ago. “The most important is that you confirm that the patient is suffering … ‘You can’t go outside, you don’t want to see your friends anymore, you sleep separate from your partner, so we want to treat you.’”

Within a few weeks, most patients can be convinced to begin medication. A 2014 paper showed that some drugs for delusional disorders also happen to kill parasites, and Vulink sometimes uses this research to help persuade patients that these antipsychotics will relieve their suffering.

Ridge, of course, does not have the power to prescribe. She hopes instead to steer many of these people toward the proper professional. She knows, though, that someone with DP is likely to have already seen a long string of medical doctors. Visiting Ridge may be a last resort; she doesn’t want to scare them off.

Her assessment begins as soon as they walk in the door, before a word is exchanged. “It’s written all over their face,” she said. “This stiff movement, very focused, you know, clenched hands, tight body position, clear indications of high anxiety. And so my approach is to try to get them to relax. I’m somewhat jocular in the language, I keep the language very simple.”

She asks them to sit down. And then, from across the desk, she listens to whatever is bothering them. What might seem like insect bites could be caused by almost anything — mold, drug interactions, thyroid problems, a new detergent — so she takes a careful history. She asks where they live, with whom, what health problems they have. She asks about their pets.

Once, she was called in about the laundry workers at a hospital who were all convinced they were being attacked by insects. When Ridge arrived, she could feel it herself: a distinct itchiness in the air. The culprit turned out to be an industrial dehumidifier — it made the room buzz with static electricity.

When the person brings her samples, she picks through them carefully. She dumps them into a lab dish, and with the flick of a switch and the twist of a knob, they come into focus under Ridge’s microscope. The machine is connected to a screen facing outward, so everyone in the room can, at least for a moment, see through an entomologist’s eyes.

The ensuing examination is collaborative: no, that thing is not a mite but a twist of hair, not a beetle but a ball of lint. She listens, and listens, and listens, not agreeing with them, but not dismissing them either. “The medical profession is not allowed to offer time,” she said. “I can offer time.”

It sometimes takes her months to win clients’ trust. At first, they argue, citing websites like stopskinmites.com as proof of their infestation, and Ridge needs to counteract the misinformation they have found there. “This is a piece of lint,” Ridge told me, pointing to a photo that the website suggested was a mite. She sees these sites as a ruse to get people to buy pseudo-medical products, and as a danger to her clients.

“Often in the early stages there’s lot of pushback,” she said, “but they keep coming back, which means they have — deep down — doubt. I keep reassuring them: I’m not judging them.”

She can be maternal, careful to validate what her clients are feeling, becoming stern when she needs to. She sometimes organizes family interventions in a conference room at the Experiment Station, with as many as 11 relatives around a table, trying to address the problem together. She likes “the satisfaction of seeing someone healed.”

“I can help those cases when they have not been invested more than six months, and when they have support from loved ones or friends,” she said. “Those that have become isolated, and have developed habits of self-treatment are very hard to pull back from the brink.”

They don’t often open up at first. As the relationship develops, though, they begin to confide in Ridge. And there is usually something to confide, some emotional upheaval in the background: a divorce, a stressful move, the loss of a loved one. She saw an uptick in these cases right after the 2008 recession. After the physician-researcher’s death, she found out that his family had left him. The separation had happened right around the time of his first bites.

When clients comes in, Ridge puts their samples underneath her microscope, as she demonstrates here with bedbugs.

One unseasonably warm day in late January, Ridge was in her lab showing me videos of a particularly gregarious colony of bedbugs when the service bell rang on her front desk. Waiting for her was a white-haired woman in a puffy coat, wool scarf, and black-framed glasses. When she spoke, her words were halting. “I need some help,” she said, pausing, as though afraid to continue, “identifying a bug that is not allowed in my house.”

“OK, that’s what I’m here for,” said Ridge. Her wry tone was gone; instead she sounded like a kindergarten teacher, her voice an octave higher than usual and almost aggressively chipper.

The woman looked like she could use the comfort — and maybe a strong drink. “I only hope it isn’t a cockroach,” she said, sitting down.

Ridge took the container that the woman had brought in, and tipped its contents into a plate. Out fell a jumble of spiny legs, antennae, folded up wings. Ridge fiddled with the microscope and the bugs came into focus on the attached screen.

“Hi, guys,” said Ridge in the same bright voice, as the insects began to untangle themselves. Then, she added, under her breath, “They’re just scared out of their minds.”

“Well, they should be!” the woman said. “They should stay out of my house!”

The woman’s house had been completely bug-free for 30 years, she said. But then, just before Christmas, she had found one of these red-and-black critters in her living room. She found another the week after — and another, and another. She was worried they might be cockroaches. She’d gotten new furniture; could that be the culprit?

No, Ridge said. They weren’t cockroaches, and they hadn’t come in on the furniture. These were box elder bugs, she explained. They feed primarily on the seeds of the female box elder tree. Sometimes, in winter, instead of hiding out in rock crevices or tree hollows, they find their way into the warmth of people’s houses. They were harmless. No need for insecticides.

“They don’t bite?”

“Nope.”

“Do they carry disease?”

“Nope.”

Under the microscope — and, simultaneously, on the screen — the bugs began to scrape their dusty black legs along their beaks, the arthropod equivalent of washing one’s face.

Ridge took her time elucidating every aspect of the case. She drew a diagram of where the woman’s house might need caulking, read aloud and then printed out official information about box elder bugs and their host trees, and suggested a broom and dustpan for pre-caulking bug-removal. No, there was no risk of them being transported on her shoes and infecting anyone else’s house, Ridge said. No, she was under no obligation to inform anyone else that she had a bug problem.

Through pursed lips, the woman let out a sound of relief: “Well, that’s wonderful. Boy, I never thought I’d say that it’s wonderful if I identify a bug in my house.”

After she’d left, and Ridge had let the bugs out into the grass outside, she walked back toward the bedbugs and cockroaches in her lab.

“Did you see how her demeanor was at the beginning?” she said. “Tense, to say the least. And then as she began to get more educated … how it completely lifted, this mantle of anxiety?”

The bugs that had been tormenting this woman were real. They were made of chitin and myofibrils and hemolymph if not quite flesh and blood; they crawled, felt warmth, ate seeds with their piercing-sucking mouthparts. But it wasn’t hard to see how this creature could potentially shape-shift in her mind, from a harmless half-inch garden-dweller to something much more sinister: an uncontrollable swarm. Already, these few bugs had taken up residence in her thoughts. That could happen to anyone.

And Ridge knew just how fragile the boundary could be between the insects in someone’s house and the ghostly insects of the mind. She knew better than to point out that the woman was sitting right beside a tankful of Madagascar hissing cockroaches, their sleek, segmented bodies dozing a foot or two away from her left shoulder, waiting harmlessly for nightfall. “Insects are most often not the problem,” she said.

The problem is us.