For Your Consideration: The Incredible... Roach!

JESSICA WARE (Curator, Division of Invertebrate Zoology): Oh hello? Who’s this cute little guy? Some adorable little spotted beetle? Nope. Surprise! It’s a cockroach! 

I get it. Lots of us don’t like roaches. A study funded by the U.S. Fish and Wildlife Service found that the most hated animal in America was the cockroach. There’s even a name for the fear of roaches— katsaridaphobia. Will no one love them?

Maybe you just haven’t met the right roach.

I’m here to tell you: roaches are amazing. There are red ones, green ones, metallic ones, even multi-colored ones. They have complicated social structures, can make different sounds with different meanings, and they’re some of the best parents in the insect world. (They will eat their young, but let’s not talk about that.) 

More importantly for us humans, they have an important role to play in ecosystems around the world. But how? 

So, we might not love roaches… but the world needs ‘em. Stay with me and while you might not exactly fall in love with roaches, you’ll at least learn to appreciate them as six-legged frenemies!

DIRECTOR [off-camera]: Who do we have here?

WARE: This is Gromphadorhina portentosa, or  the Madagascar hissing cockroach. 

DIRECTOR [off-camera]: It’s a little bigger than the ones that I have in my apartment. At least so far.

WARE: Well, more than 99% of cockroaches have never seen a kitchen sink. There’s over 7,000 species and the majority of cockroaches have actually lived their entire existence outside of the human condition, away from people, away from human dwellings. 

The rest of the world’s roaches live all over the place—in rainforest treetops, the edges of streams, and deep in caves—from the equator to northern latitudes. Even a species that ranges above the arctic circle.

DIRECTOR [off-camera]: What I’m hearing is that there are a lot of roaches out there.

WARE: Yes, but they don’t all look like you might think. They’re actually incredibly diverse and many of them are really beautiful! Among the world’s thousands of roach species, there are turquoise roaches, snorkeling roaches, and roaches with the incredible alchemy of turning atmospheric nitrogen into nutrients.

DIRECTOR [off-camera]: So, if they’re not climbing out of my drain, what are roaches doing with themselves?

WARE: Well, I mean, most cockroaches are kind of gregarious. Some maintain bonds by mutual grooming and touching. And lots of them take care of their kids! These guys right here [indicates hissing cockroach] actually feed their young. Cockroaches are the largest group of insects that exhibit parental care. 

DIRECTOR [off-camera]: Do they talk to one another?

WARE: Well, cockroaches can communicate. Often what they’re using are chemical communication. So, they have these really long antennae. If you’ve ever taken the time to sit and look at cockroaches, often a big part of what they’re doing in the day is actually cleaning their antennae.

Cockroaches are actually really fastidious. Their chemosensory tools that they have in their antennae, these small sensory pits that can pick up different chemical cues—those need to be really, really clean in order for them to be able to best communicate with each other.

DIRECTOR [off-camera]: That’s intriguing, I won’t lie, but it’s gonna take a lot for people to love cockroaches. What else would make me like them?

WARE: Well, I mean, the world as we know it would look really different without cockroaches. We really need them because they’re an essential part of the nutrient cycle—something that’s critical for healthy ecosystems. They’re like lil sanitation workers—breaking down leaf litter and animal waste, and returning nutrients to the soil. And they’re incredibly important as food for other animals! They may even be the single most important prey for small vertebrates like lizards and birds in tropical rainforests.

DIRECTOR [off-camera]: If roaches are so amazing, why are they so easy to hate?

WARE: Well, I mean, we tend to think of cockroaches, we tend to think of the really small number that are pest species. And there’s a few species in particular that tend to have adapted to live in and amongst human dwellings—the American cockroach and the German cockroach. Those pests are so dependent on humans that at least the German cockroach no longer exists in the wild. This is bad for us because pest species can have big impacts on our health. They’re well-established as a significant source of severe asthma for many people.

Dr. Megan Wilson is an entomologist who now focuses on pest management. Her job involves getting rid of roaches in places where they can be a nuisance or harmful to people, but she’s really fascinated with their biology. So, we went out to the woods to see if we could find some roaches in the wild!

I’m surprised it’s not a more common pastime.

So in your experience in pest management, like what- what are some of the things that people tell you that really freaked them out about cockroaches?

MEGAN WILSON (Entomologist, Field Supervisor): Flying. They don't like how they run. They don’t like how they scuttle, and on top of it, too, there’s kind of a stigma with them.

WARE: Because people fear, like, if you have roaches, then people think that you are unclean or that you've done something wrong. My mom actually, she lives in northern Ontario and she found a cockroach, and she freaked out. And I was like, girl, this is like a tiny Ontario wood roach. But she just only associates them from TV and movies as being like something a New Yorker would have in their apartment, so she was really panicked. And I just reminded her that there’s like cockroaches all around her in those woods. And they live outside of the human condition. They're like, not part of our story.

Roaches!

WILSON: I got a wood roach!

WARE: Look at that! A little- That’s a younger one. Slightly older one.

WILSON: See, even in the winter, you still find stuff, if you flip logs.

WARE: But we’ve been freaked out by roaches for centuries. Ancient Egyptians had spells to ward off roaches. Today, we have something called integrated pest management. 

WILSON: There's this kind of idea of taking the biology of the pest, and, the ecology of the system you're working in and integrating them together. The insect is a symptom of a problem. The insects’ presence can tell you something about what you need to fix. 

WARE: Pest roaches have a list of undeniably unlikeable—but incredible—traits. They’re the world champions of chemosensory reception. Their omnivorous diet can incorporate everything from wallpaper glue to donuts. And their incredible immune systems give them resistance to both disease and pesticides.

150 million years ago, some of those adaptations laid the genomic groundwork for the evolution of the very first insect society—termites. Yeah, that’s right… termites are roaches, too. 

When you talk about termites in your work, how do you- Do you refer to them as, like, roaches? Do you refer to them as termites?

WILSON: I mean, I talk about them as termites, like with the common name, but I tell people they're very specialized roaches, very social, wood-eating roaches.

WARE: Yeah. Fancy social, wood-eating roaches.

After nearly a century of debate, in 2018, the Entomological Society of America officially recognized these animals as part of the order Blattodea, the roaches.

Termites might not have quite the charisma of flower-visiting bees or industrious ants, but they also have incredibly complex communication and coordination. They optimize transportation routes. They build climate-controlled mega structures—some taller than skyscrapers… at least, relative to the size of their construction workers. They’re keystone species, critical to many habitats. Termites, like some bees and ants, exist in societies that we call “eusocial.”

WILSON: It’s spelled e-u- social. “Eu-” means true, so it's “truly” social.

WARE: “Truly” social or eusocial insects like termites have three characteristics: multiple generations living together, shared parental care, and they have a division of labor. So, in termites, that takes place in the form of three castes.

WILSON: You have workers and soldiers and reproductive castes. 

WARE: Reproductives are the termite king and queen. Termite queens can live for more than 20 years! 

We don’t like it when termites turn their social stomachs towards our homes and buildings, where their damage can cost billions of dollars annually. But in the wild, they—along with earthworms—are arguably the most important engineers in terrestrial ecosystems. A recent study even calculated that termites make up to 40% of all biomass in the soil.

I think when we think about insect societies, they’re important in their own right because they often function as kind of superorganisms. And they can really shape an environment. But they’re important to humans because we’re fascinated by social behavior. How is it possible that something so small and wee could have a really complex, you know, society?

C’mon, how amazing is the cockroach???

I like to think that if people knew more about the- this cool biology of these roaches, maybe people would, like, learn to love the roach.

WILSON: Sure. Or at least say, ew, but they are cool.

WARE: Yeah. Ew. Cool.

[Credits roll]

WARE: So, the first Black woman to get a Ph.D. in entomology was Margaret Collins. And Margaret Collins worked on termites.  She produced foundational work on termite ecology, physiology, taxonomy, and defensive behaviors. She described new species.

She had a reputation for being a really prolific and profound scientist, and so she was invited to give a talk at a white university. And when people found out that this Black woman was going to be giving a talk in an academic series, there were bomb threats that were called in and her lecture was canceled. But her son recalls that even in the face of this threat, she just moved the talk to another location.

She was committed to civil rights. She drove cars for the Tallahassee Bus Boycott—a student-led action sparked soon after the better-known one in Montgomery—and she was chased by police cars and tailed by the FBI.

She really had to fight against pervasive sexism and racism and despite all of that, she is quoted as saying, you know, “You have to do the work.” And she did the work, like throughout her entire life.

She was a professor at Howard University, Florida A&M University, and Federal City College. And eventually she became a research associate at the Smithsonian, where she had a really extensive field program.

She did a lot of her field work in Guyana, actually. And that is actually a place where I’ve done a lot of my field work. So, when I go to Guyana and sample termites, I often think, “I wonder if these are some of the descendants of the termites that Margaret Collins sampled.”

She was really a leader in field biology and certainly an inspiration to many of us who have gone on to study termites. And I have her portrait here in my office! Who are your science heroes? Tell us about them in the comments!