Secrets of the Swarm: Maeno Ould Koutaro / Entomologist

"Direct Talk"

Our guest today is Maeno Ould Koutaro,

an entomologist who studies the desert locust.

The damage to crops that swarms of desert locusts can inflict

has become a global issue.

For eight years, Maeno was out in the field in Africa,

figuring out how these locusts live and behave.

His research is winning international recognition.

In 2021, one of his papers was published in a leading American science journal.

Maeno hopes that his work can reduce the damage done by desert locusts.

He shares what he's learned so far, and his future ambitions.

Since the dawn of humanity,

primarily in Africa and around the Middle East,

desert locusts have broken out in massive swarms and devoured crops.

It's what locusts do.

My goal is to develop eco-friendly techniques

that prevent locusts from doing this.

As I undertake my fieldwork,

I'm constantly trying to figure out the patterns behind locust activity.

The nation of Kenya.

A swarm of desert locusts fills the sky.

This is the phenomenon that Maeno studies.

This footage was taken during an outbreak in 2020.

The massive swarm of locusts devoured crops and virtually all other plant life.

This upsurge spread through East Africa and the Middle East.

Control efforts were estimated to have killed more than 500 billion locusts.

However, locusts don't always move in giant swarms.

Here is a typical desert locust nymph.

Adults have a similar muted green or brown coloring,

and they live individually, not in large packs.

But when locusts multiply and cluster together,

their colors change to bright yellows and pinks.

An outbreak begins.

Desert locusts exhibit an ability called "phase polyphenism."

They change their behavior and morphology when they come into contact with each other.

When they're living at low density, they're green and reserved - a "solitary phase."

But when they are surrounded by other locusts,

and they stimulate each other more and more frequently,

they shift into what is called a "gregarious phase."

In this phase, the nymph will take on very flashy colors,

maybe black and yellow,

and what's more, they'll exhibit particular behaviors.

They become attracted to each other, and they'll move in the same direction.

And they really do move.

An adult swarm can cover 100 kilometers a day,

causing widespread havoc almost instantly.

In the 2020 locust upsurge,

over 48 million people faced acute food insecurity.

It's believed that, historically,

large outbreaks occur when you have heavy rains in the year after a drought.

Although no one has scientifically proved this claim,

as far as I can surmise, when you have a drought, almost all living things die,

including birds and other insects, their natural enemies.

The following year, you get a downpour, and plants begin to sprout again.

The first creature to reach these plants will be the desert locust,

and so we see an explosion in their population,

after which they fly on to the next area.

They migrate in search of better conditions.

That's how it seems to work.

And I fear that, in the future,

climate change will lead to an increase in extreme rains

and a mix of various factors that will in turn

make locust outbreaks more likely to occur.

Current efforts to prevent these outbreaks typically involve spraying pesticides

from airplanes or automobiles.

But Maeno says that this approach has obvious drawbacks.

If you get too close to the locusts, they just fly away.

So you have to spray the pesticide on them from a slight distance.

But you need to get the pesticide on the locust directly,

and it's pretty tough to hit a moving target.

That's one challenge.

And there are concerns about what pesticides do to the environment.

After you spray the pesticide,

some types stick around longer than others.

They linger.

Some pesticides stick around for quite a while,

and this can have an adverse effect on other life in the area.

This is an important issue.

Really, we should be striving to avoid the use of pesticides as much as possible.

In order to make this a reality,

Maeno has worked to identify patterns in desert locust behavior.

He became particularly interested in patterns of breeding.

In the West African nation of Mauritania, most of which lies in the Sahara Desert,

Maeno has spent eight years doing field research.

He discovered the unique way that desert locusts form groups in order to reproduce.

According to Maeno and his colleagues,

before entering their "gregarious phase,"

desert locusts live in separate male and female groups by day.

Then, just before egg-laying, the females come to the male group,

mate, and lay their eggs during the night.

In 2012, during my field research,

I came across a group that was all male.

As the evening began, the females flew over and mated with the males.

When night fell, you saw countless pairs of locusts laying eggs,

all in this big group.

This fascinating phenomenon was occurring right in front of my eyes.

I continued collecting data, patiently,

and it revealed that only females that had eggs were coming to the male area.

We don't know exactly why they lay eggs in groups,

but if you're in a swarm, it's less likely that you'll be attacked.

And in particular, the egg-laying process takes several hours.

The female thrusts her abdomen into the ground to lay her eggs,

and she has to stay like that for hours.

And so, for that duration,

being in a group makes it much less likely you'll be eaten.

I'd say that seems to be the strategy at play here.

These photos show a nighttime group egg-laying.

Maeno believes that we can use our knowledge of this behavior

to control locust populations efficiently.

During these group egg-layings, the males and females are formed up in pairs.

They stay together for a good while,

and lots of these locusts are crammed together in a compact area,

which means we can spray pesticide efficiently.

And moreover, we'll be able to utilize all sorts of green technologies

that don't require pesticides in the first place.

Our hope is that figuring out

when, where, and how these mass egg-layings take place

will be extremely useful in terms of pest control.

It'll be an extremely effective method.

Maeno was born and raised in an area full of nature,

and became interested in researching insects after reading a certain book.

When I would go outside, I would see all these insects moving all over the place,

and I wondered why they moved the way they did,

why their bodies were shaped the way they were.

I had so many different questions about insects.

"Fabre's Book of Insects" answered all my questions,

and that's when I realized the power of research.

Being an entomologist seemed so cool.

In my young mind, I imagined a future studying insects.

Maeno has been studying the desert locust since graduate school.

Back then, he would spend his days observing locusts in the lab.

In fact, most people studying the desert locust did so in a lab environment,

using lab-bred specimens.

With lab research, you can make a research plan that's convenient for you.

In contrast, out in the field,

you might not end up seeing any locusts in a given year,

or it can be really tricky to access the areas where the locusts are.

I think their unique habitat and ecology

contributed to keeping researchers away from conducting fieldwork on them.

But Maeno was determined to see how locusts actually lived.

I didn't know what the life of the desert locust looked like out in the wild.

I felt more and more sheepish just observing them in this artificial setting.

I saw them every day, but I doubted that I understood their true nature.

In order to continue my research, I knew that I had to see them in the wild.

I made the decision to go to Mauritania, to undertake my research there.

In 2011, Maeno traveled solo to Mauritania

and embarked on a comprehensive field survey.

He began working with a local institute that researched locusts,

and the chief scientist was impressed by his passion.

Maeno was bestowed with the honorary middle name "Ould,"

which means "offspring or son of."

Maeno then lay in wait, hoping to see the locusts he couldn't find in a lab.

If you have locusts in a breeding box,

most of them will stay in the upper part.

And in the wild, at night,

locusts often spend the night perched on large plants.

Probably the locust does this to prevent being attacked

by predators once it gets dark.

Whenever possible, they escape to a large plant that serves as an effective shelter,

and spend the night there.

These are the sorts of things you can't really figure out in the lab.

At long last, I knew that I was starting to see their true behavioral patterns.

Maeno was also able to fulfill a childhood dream -

being totally surrounded by locusts.

He wore a green bodysuit to make himself look like a plant,

and jumped right into the swarm.

If you're not playful, your work will only ever go in obvious directions.

It might be a crazy dream that holds the key to controlling locust outbreaks.

For that reason, I do believe that, as a researcher,

having a sense of fun and playfulness is very important.

Maeno wants to use his field experience

to teach the next generation about desert locusts.

Have a look at this video.

Today, he's been asked to give a presentation on his research

at a girls' junior high school in Tokyo.

After his talk, there's time for a Q&A session.

You used the term "natural enemy" several times.

Would that be things like scorpions?

In that region, birds are their main natural enemy.

This isn't an issue we really face in Japan,

but the point is to think about issues that might be unfamiliar to us.

If we can instill that spirit in the next generation,

then they'll have the determination to take on problems

that might take Japan by surprise.

That's one reason I do this.

Another is... how do I put it?

The locust itself.

I study insects,

and I want to show as many people as possible why locusts are so amazing.

That's the thinking behind these lectures I give.

(Do you have any words to live by?)

"Follow your dream, better yourself."

In my case, I've been following the same dream I've had since I was a child.

And in order to stick with a dream,

you have to keep growing as a person, and I believe I've been able to do that.

That's the meaning of these words, "Follow your dream, better yourself,"

and it's the motto that guides my own work.

In the future, I'd like to write a book like "Fabre's Book of Insects,"

the book that gave me my dream.

I want to publish my own book of insects

that conveys the fascination of insects to the next generation.

That's become my dream now.