It’s not often you get to witness one of the most brutal acts of the natural world up close: bed bug sex.
But there I was, at North Carolina State University’s Department of Entomology and Plant Pathology this May, as researcher Saveer Ahmed arranged the meet-cute in a lab dish. The more oblong, poppy seed-sized male slowly puttered his way over to the female and seemed, from my vantage point, to give her a horizontal bearhug. He was actually stabbing her abdomen with his penis-like aedeagus, trying to inject his sperm into her.
All in all, it was a good start to my day with Zachary DeVries, a 30-year-old urban entomologist at NCSU, and his fellow pest scientists.
For some six years at NCSU, as a fledgling scientist and currently postdoctoral researcher, DeVries has cut his teeth studying the pests that plague our homes, focusing on the common bed bug (Cimex lectularius) and the German cockroach (Blattella germanica).
His work has ranged from studying how bed bugs learned to fight off the chemical weapons that almost wiped them out to showing how worthless bug bombs are at clearing out a cockroach infestation. But he’s soon moving on, having recently accepted a new job at the University of Kansas, where he’ll get to run his own lab starting next year.
“What really drives me to work with bed bugs and cockroaches, pests that do gross a lot of people out, is the fact that I know they create serious problems,” DeVries told me over the phone.
The unglamorous and grimy research done by urban entomologists like DeVries highlights the remarkable, annoying resilience of these pests. In a more grim way, it also makes clear the invisible burdens that disadvantaged and poor people have to carry, since they’re usually the least able to get rid of these troublesome bugs. But DeVries and others like him hope to push back on that disparity, by fighting for a world where vulnerable people aren’t just left to fend for themselves against these pests.
The feeding zone
One fear scratched at the back of my mind as I travelled out to North Carolina, a fear goaded on by my supposedly well-meaning friends and co-workers: What if I brought the bugs back with me? But according to DeVries, I shouldn’t have really been too worried.
“We’ve never had a single incident of anybody taking bed bugs home with them. I think the number one thing is just to be cautious,” he reassured me before my visit.
Once at the lab, I could understand the lack of fuss. Under the cover of night, bed bugs’ hunting skills are impressive. They have a keen sense of smell highly tuned to our body odor and the carbon dioxide we breathe out; a limited but useful vision that can spot dark colours where it’s likely to be safer; and pheromones they emit to signal to other bugs that a location is good enough to bunch into. But the ones I saw in the dish, just fed, were pitifully slow walkers whose meager climbing ability was trounced by a raised, smooth barrier.
German cockroaches, on the other hand, are more nimble, but the risk of them breaking out isn’t nearly as perilous. Bed bugs prey on us; cockroaches prey on the food we leave behind. For cockroaches, a little dab of petroleum jelly around the containers they’re kept in is enough to stifle their escape attempts. They’re also more generous lovers than bed bugs, in so much as an insect can be: The male offers the female a gift of sugar produced by one of his glands in order to entice her into mating, which, if the female accepts, will also provide her with some much needed nutrition for the dozens of eggs she can produce at once.
I still kept my distance once I was escorted to the rearing room, though, where DeVries and his co-workers feed the bed bugs. Decades ago, scientists often quite literally took upon themselves to nourish their stock, using their bodies as a feeding trough. Many would simply hold up a container of bed bugs up to their arm and let nature take its course. Nowadays, almost no one does that, DeVries said.
The NCSU State team instead relies on a litre of rabbit blood each month to replenish their thousands upon thousands of bed bugs. Cow blood, as it turned out, wasn’t nourishing enough, while chicken blood was too expensive. And the use of human blood taken from blood banks, an option the team is exploring for the future, would ironically have to go through more regulatory red tape than the bed bugs themselves.
When it’s feeding time, the room is kept mostly in darkness, with only a red light to illuminate the devices that mimic an authentic culinary experience for the bed bugs. The apparatus holds a container of water that’s heated up with circulating air pumped through two holes at the top, warm enough to match our body temperature. Then the jars containing the bed bugs—speckled with poop droppings that emit a faint metallic smell—are raised on a platform just underneath the container.
Blood is dropped into a hole in the middle of the container that the bugs can climb right up next to. But importantly, there are also thin layers of a specific type of tape, usually used to help grow plant grafts, between the top of the jar and the water container—layers that act as a faux skin for the bed bugs to pierce through with their straw-like mouths, all so they can get to their sweet, sweet blood. NCSU scientists were even more inventive in the past, using condoms as their skin substitute.
Without all this stagecraft, DeVries explained, the bugs simply won’t bother to feed, even if there’s blood placed right in front of them.
Bed bugs can infamously survive for weeks up to a year without blood, depending on the weather and which of their five stages of development they’re in (fully mature adults in the modest cold survive the longest). But they still thirst after blood the same way we might crave a burger at the end of a long day with a skipped lunch. The bed bugs I first saw in the morning were sluggish. But when I exhaled on a jar of unfed bugs, I was thoroughly creeped out at how fast they scrambled up the accordion-folded piece of paper that was their home (the folds give them plenty of nooks and crannies to hide in). My breath was a dinner bell, calling them to the human feast. Equally eerie was the jar of bright red bugs I saw next, fully gorged on blood.
Cockroaches, by contrast, do just fine with a bottle of water and some pet food pellets tossed into their box domiciles every once in a while—such is the joy of being an opportunistic scavenger.
“I honestly think we spoil them really, they don’t need any of this set-up,” remarked DeVries when we visited the menagerie where various cockroach species, including the gigantic and Hollywood-famous Madagascar hissing cockroach, are kept.
DeVries and his team aren’t just raising bed bugs and cockroaches for the fun of it. Different populations are brought to and stored in their lab from all over the world—and even from across time—so they can then run experiments on them.
The latter feat is largely thanks to a single scientist and military entomologist named Harold Harlan, who kept alive in isolation for decades a lineage of bed bugs that existed during the 1970s, back when they were easily killed by any common pesticide spray. Once bed bugs staged their comeback around the 2000s, Harlan graciously shared his bed bugs with the rest of the field.
This “Harold Harlan” or “Fort Dix” strain is now used by scientists at NCSU and elsewhere as a control group to compare to the wild, resistant bed bugs that have since sprouted up. But some bug populations at NCSU are also home-grown, cultivated from real infestations of the homes that they visit.
Once we finished the lab tour, the team, with the permission of their study subjects, was gracious enough to allow me to tag along on one of their scheduled roach hunts.
Teeming was the only word that came to mind when DeVries and research specialist Rick Santangelo pulled out the refrigerator they presumed was one apartment’s major source of infestation. Boy, were they right.
A veritable sea of almond-sized cockroaches flooded out from the back of the fridge, enough to momentarily swarm the soles of our shoes, as did a blast of pungent air. And while German cockroaches aren’t known for their sounds, the sheer mass of insect antenna and feet bashing into each other filled the home with a dreadful chittering noise. It was, according to DeVries, one of the most dramatic invasions he had personally seen up close.
Not that you could really tell that from looking at either him or Santangelo. While I did my best to not immediately leap onto the kitchen stove as the roaches scrambled out, looking to get away from the harsh kitchen night, the two just playfully cracked jokes as they casually vacuumed the roaches up for samples to take back to the university and laid out poison bait throughout the home. Periodically, they also talked with the residents to ask for permission to enter a certain room, or to update them on the treatment’s progress.
“I think the more you do this kind of work, you just get inured to seeing it,” DeVries said at one point, no doubt noticing my fear-stricken appearance.
Growing up in poverty in the heart of Brooklyn, New York, I wasn’t a stranger to cockroaches. (Bed bugs, thankfully, were never my roommates.) But in my later years, as our family’s and eventually my own housing situation improved, roaches had become more of a distant memory—though not for lack of trying on their part. With more resources, it was simply easier for me and my family to get rid of any infestations before they got out of hand. And as DeVries emphasised time and again during our conversations, socioeconomic disparity is the No. 1 factor that makes families such as the ones we visited so vulnerable to these pests.
Bed bugs and cockroaches are indiscriminate in their targets. Anyone who leaves uncovered pet food in the kitchen at night is putting themselves at risk for roaches. (“I make an effort to just explain to people that that’s exactly how we rear cockroaches in the lab,” DeVries noted.) And bed bugs will enjoy the blood of the 1 per cent as much as anyone else’s. But people with few financial means are less able to afford the variety of pest-control options available, whether bought over-the-counter or professional.
As I gingerly used a gel bait tube handed to me by DeVries, he ran down the rough costs of decent cockroach self-management. For a serious cockroach problem, it might take several applications of a bait product throughout the home, at around $US15 ($22) to $US20 ($29) dollars per treatment, repeated every few weeks. While that might not seem like much, it’s still less than the $US3 ($4) to $US4 ($6) dollar cockroach spray you can buy instead, or a $US10 ($14) bug bomb.
The trouble is that these cheaper products simply don’t work anymore, thanks to widespread insecticide resistance and poor design (bug bombs and sprays rarely reach into the crevices where roaches actually live). Baits can also be resisted by roaches to an extent, but so long as you rotate the specific ingredients and formulations you’re using, it’s manageable. Without having that knowledge upfront and/or the financial cushion to afford and properly use the baits, let alone a professional extermination, though, people use the sprays and bombs to little effect. And in the wake of that failure, many people just learn to tolerate the roaches.
This conundrum is even worse for people with bed bugs, since the chemical weapons that nearly drove them to extinction before the turn of the century are now practically useless by themselves.
Starting in the mid-20th century, the pesticide DDT—used in homes and on crops—devastated bed bug populations. Even after DDT was banned from most countries in the 1970s, household pesticides made from pyrethrins were still able to reliably kill them. All the while, though, the bugs were steadily evolving resistance to both chemicals, which attack their nervous system in a similar way. The two simple mutations responsible for this resistance are now found in virtually all wild bed bugs, and they’re also starting to pick up other mutations that fend off newer classes of pesticides that exterminators are turning to, like neonicotinoids.
Unlike with cockroaches, we also haven’t developed anything equivalent to poisonous bait, an issue that circles back to bed bugs’ stingy appetite.
“There’s no way you can take care of that problem on your own. Or if you do it—and there are rare cases where people have—it requires an incredible amount of time, diligence, and almost a sense of paranoia. Which is not what you want to be living with,” DeVries noted. Most people, though, will simply waste their time or occasionally burn their home down with internet-bought or home remedies.
It isn’t that we don’t know how to manage bed bugs, though. Faced with a bug resurgence, exterminators, in cooperation with scientists like DeVries, have actually developed effective methods in the past decade for finding and treating them. These involve techniques like canine sniffers, heat treatments, mattress encasements, and follow-up inspections, in combination with some insecticides. But the sticker price of this diligent care runs into the thousands of dollars—a cost that either tenants can’t pay or that liable landlords (depending on the state’s housing laws) refuse to shell out.
And all of this gets compounded by the fact that if you don’t treat every single infestation in a large apartment complex or building, the bed bugs or roaches can eventually regroup and spread out again.
“So what happens is, a lot of the time, that you force people into these situations where they can’t afford professional pest control. They just have to learn to live with the problem,” DeVries said. “It’s terrible—it should not be an acceptable way of life. But unfortunately it is.”
Because of that reality, it’s often people living in affordable or low-income housing, including all of the residents we paid a visit to that day, who bear the brunt of cockroach and bed bug infestations. Research on the topic is limited, but a 2016 survey of more than 2,500 low-income apartments across 43 buildings in New Jersey found that an average 12 per cent of apartments in a building were infested with bed bugs; some complexes had infestation rates as high as 30 per cent. Cockroaches, meanwhile, are nearly universal in low-income housing.
This abundance isn’t just unseemly, but bad for people’s physical and mental health. Cockroaches are a common cause of asthma and other allergies, especially for young children, and they can contaminate food with the germs that cause typhoid fever, cholera, and other diseases. Bed bugs, by contrast, are a bit more complicated.
Scientists have long searched for a possible connection between bed bugs and physical illness, but largely come up short. There’s research in the lab showing that bed bugs can spread the parasite that causes Chagas disease, a usually mild but sometimes chronic ailment that can damage the heart, much as their distant cousin, the kissing bug, does. But there’s no evidence of this happening in the real world, at least yet. DeVries’s own work, however, has suggested that it’s not bed bug cooties we have to worry about—it’s their histamine-filled poop that lingers in the air. And this extra histamine, a naturally produced chemical that normally helps the body’s immune system stand ready against foreign invaders, just might worsen or cause allergy-like symptoms in people who regularly inhale it, DeVries speculates.
At this point, he’s only shown that environmental histamine levels are much higher in bed bug infested homes, and stay dramatically high even after the infestation is taken care of. But we’re simply not sure what can happen to people who are chronically exposed to bed bug histamine.
“We’ve never had a case of histamine levels this high, inside people’s homes that close to places they were sleeping,” he said.
Quite frankly, he added, there had never been any good reason for scientists to look for airborne histamine in the first place. While histamine can be found in some foods, there was no indication that anything else could be a source of exposure. And it was only in 2015 that scientists first made public the discovery that bed bugs even emit histamine, likely as one of their many pheromones.
If DeVries’ theory, which he plans to continue pursuing at the University of Kentucky, does pan out, it would further explain the health divide between the haves and have-nots. Families living below the poverty line are 50 per cent more likely to have their children develop asthma than those from middle class families, by some estimates, while rates are also higher among black and Hispanic families. They’re also less able to afford the medication to manage these conditions, and their children suffer for it, with more allergy-related missed school days, emergency room visits, and even deaths than the general population.
“One of the focuses I have, and will take with me to my new position is this idea of environmental justice, or social justice. And it’s this idea that just because somebody doesn’t get to have as much money, as much resources, etc, that doesn’t mean they should be at a disadvantage in terms of any aspect of life, but certainly not their health,” said DeVries.
Our eternal neighbours
Urban entomologists like DeVries often develop a close relationship with their neighbours. In the case of the NCSU team, they regularly go door-to-door in affordable housing areas, offering their services in exchange for participation in their field studies. Other times, in their role as an extension agent—a term borrowed from agriculture—they’ll reach out to the community more broadly, including local pest exterminators, through educational programs. They even take the occasional phone call asking for advice.
“It’s not just part of our job. It’s our social responsibility to identify the risks, present the risks to everyone. So we know what they are, and everything’s out in the open,” said DeVries.
Watching the two interact with the residents, who often hailed from outside from the U.S., I was heartened by the respect they afforded them, with Santangelo in particular speaking to them in their native language when he could. It’s a respect that’s not necessarily extended to many people dealing with these pests. To have cockroaches or bed bugs is to often be seen as dirty and untouchable. And even if bed bugs don’t make us physically sick, they can certainly cause mental anguish and isolation, as friends might suddenly choose to avoid seeing you. In some cases, chronic infestation have likely contributed to people’s suicides. And even the fear of bed bugs has almost certainly sparked episodes of delusional parasitic infestations. It’s no wonder, then, that many people simply bear their pest problem alone.
None of this shame or stigma is warranted, of course. For one, person-to-person transmission of bed bugs is actually very rare, given their nocturnal preference and lacklustre locomotion. There’s even some evidence that the rate of bed bug infestations in the U.S., following their comeback, has started to plateau, DeVries said. (German cockroaches, however, remain as omnipresent as ever).
There are obviously things we can do to lower the risk of cockroaches and bed bugs invading our homes, like being careful about how we store laundry, keeping luggage secured during hotel stays, and keeping kitchens clean at night. But these pests have survived for hundreds of millions of years because they’re good at what they do. And no single group, creed, or class of people throughout history has ever avoided infestation, much as they might try to blame outside foreigners for their presence.
These human pests are a human problem, and it’ll take the village coming together to effectively control them. That’s why DeVries and others like him are strong advocates of an integrated pest management (IPM) approach, one where governments, landlords, and residents work together to proactively identify or treat bug problems, using the best available options. And the proof is in the pudding: Studies that have implemented IPM methods to root out an infestation, such as having management staff at a low-income apartment complex periodically set up gel roach baits, educating tenants on bed bug and cockroach tips, or systemically treating an entire building for bed bugs using non-chemical treatments alone or with insecticide, have found dramatic success in reducing or wholly wiping out infestations.
The real hurdle though—and one that DeVries will likely spend his entire career trying to climb—is convincing enough people that the upfront costs are worth it in the long run.
“For us to really solve the bedbug problem, we can’t just solve it on our own, we can’t just solve it one individual house at a time,” he noted. “We have to target communities, we have to try and get rid of bed bugs everywhere. Or we can just keep getting rid of bed bugs individually, you know, forever.”