Fabre in Sacheon’s Tang

”It’s true! The green locusts turned into swarming locusts!”

”But... nothing even happened! How could green locusts suddenly become swarming locusts!?”

”What sort of sorcery is this? We need to look at the others inside—huuuaaagh!”

Mandok Shingun let out a startled cry after peeking into the mosquito-net enclosure Yo-hwa had made. Elder Geolhwang and Hwa-eun also bent down to look and came away with stunned expressions.

After all, we had only placed green locusts inside yesterday.

”You didn’t... cast some secret technique overnight, did you?”

”No, I didn’t do anything. I simply left them as they were.”

”Wait, could it have been that powder you sprinkled on the grass yesterday?”

”Yes! That powder!”

They even remembered the fine dust I had sprinkled the day before.

But no—that powder merely accelerated their transformation. It didn’t cause it.

”That powder just shortened the time it takes for them to change. It didn’t turn them into swarming locusts.”

Smiling, I answered. Hwa-eun tilted her head, eyes full of curiosity.

”So-ryong, then how exactly did green locusts become swarming locusts?”

Since we’d come this far, I decided to explain properly. No more misunderstandings—I had to maintain that trust. I had just smoothed over the last bump with the ring, after all. Affection management was delicate.

Dating kind of felt like a game in that way.

You give gifts, say nice things, and raise affection points like in a dating sim. And once you raise those points, you have to maintain them carefully.

‘One careless mistake and it all drops. And then I’m the one suffering.’

“Well... the thing is, swarming locusts are...”

Up until the early 2000s, research on locust swarms was incredibly lacking.

For a long time, people believed that swarming locusts were simply a rare species of grasshopper—like cicadas that emerge en masse every 9 years.

A unique kind of insect that appeared suddenly, all at once.

But early 21st-century research revealed something shocking:

There is no such species as the ”swarming locust.”

What does that mean?

It means that there is no such thing as a “swarming locust” species.

But how could that be true, when they clearly existed—devastating entire continents?

And yet... they didn’t exist as a separate species.

Which leads to the big question:

Then what are swarming locusts?

The answer is simple. And exactly what this experiment shows:

They’re just ordinary grasshoppers that have transformed.

The insects that plague humanity are not a separate species. They’re green locusts—solitary-phase grasshoppers—that undergo a radical change.

Color, shape, behavior—everything shifts as if they’ve transformed into an entirely new being.

That’s why even scientists mistook them for a different species until the 2000s.

“They looked so different that it was only natural to assume they were something else.”

So, how does a green locust become a swarming locust?

Here’s the mechanism behind locust swarms.

There are roughly 10,000 known grasshopper species worldwide. But only about 20 species are capable of this transformation.

These belong to the Acrididae family—short-horned grasshoppers—including:

Desert locusts Australian plague locusts Migratory locusts (like the ones we caught) But they don’t just change randomly. They require specific environmental conditions to become swarming locusts.

First: a climate trigger. Heavy, sudden rains may cause explosive plant growth. Or, floods may leave only small patches of dry land, concentrating the insects. Or, prolonged drought may force all locusts into a single green zone.

These conditions lead to high population densities. When more than 20 locusts gather in a single square meter, the second condition is triggered:

Physical contact.

In cramped spaces, constant body contact becomes inevitable.

While that wouldn’t matter for other insects, for these grasshoppers, it acts as a powerful biological stimulus.

Each species has a specific body part that triggers the change when touched repeatedly.

For example:

Desert locusts: back legs Australian locusts: antennae When that contact happens enough, their serotonin levels skyrocket—multiplying several times over.

And that’s when it happens.

The green, solitary locust disappears... And the swarming locust emerges.

This change can happen in just 5 to 6 hours in laboratory conditions.

Once the transformation begins, the grasshopper’s body shifts: Its color darkens into yellows and blacks. Its wings grow longer, while its hind legs shorten.

All of it tailored for flight, migration, and mass behavior.

Scientists call this phenotypic plasticity—where the genes don’t change, but the creature’s body and behavior are dramatically altered by its environment.

Once a locust has shifted into this new form, its brain is simplified:

Two instincts remain—“eat” and “follow.”

The result is a living catastrophe: a mindless swarm that consumes everything in its path.

They lose reason. They forget survival tactics. They eat, move, eat again—devouring all life in their way.

“...And that’s how they become what you see now.”

“After that, it’s just as Hwa-eun said: they devour everything, lay eggs, and multiply. Then it repeats.”

“Then... what was that powder you used yesterday?”

“Ah. That was powdered safflower and white beans.”

”You mean safflower seeds? The ones used for lamp oil?”

”Yes. I ground the seeds into powder—before pressing the oil—and sprinkled it on the grass the locusts were eating. The powder from safflower seeds contains compounds that accelerate the transformation of green locusts into swarming locusts. Same goes for white bean powder.”

Safflower seeds, also called Honghwa seeds, contain special active components:

Three types of lignans, two types of flavonoids, and four serotonin derivatives.

Not all of them directly become serotonin, but once inside the body, they produce serotonin-like effects. Beans and nuts also contain tryptophan, a substance that boosts serotonin synthesis in the gut.

So mixing the two powders and feeding them to the grasshoppers helped speed up their transformation into swarming locusts.

After I finished explaining, I glanced at Hwa-eun. Her eyes sparkled in awe.

”A-amazing, So-ryong. You know things like this too? You’re really, really impressive. How in the world did you even learn something like that?”

”I... I’m not really sure. I think I must’ve known it before I ◈ Nоvеlіgһт ◈ (Continue reading) lost my memory.”

”Maybe So-ryong was an immortal sage who lost his memories...”

”Hahaha, let’s not go that far.”

I was a little flustered by the question about where my knowledge came from, but I brushed it off vaguely.

Her admiration seemed genuine—not just because of the ring from the day before.

The way she looked at me with honest respect... it made my chest flutter.

Being admired by the woman you love—that was something truly special.

“Spicy Fabre, you legend. I should bow to that Black Mamba a hundred times over.”

Just as I was feeling grateful again to the venomous snake that had brought me here, the praise kept coming.

”Incredible. So now we know how swarming locusts come to be. Truly remarkable.”

”To think green locusts turn into that... You’ve taught us something amazing today.”

I couldn’t help but puff up a little with pride.

Then Elder Geolhwang, who had been silently nodding, asked a question with a hopeful glint in his eye.

”Say, So-ryong... if you can turn green locusts into swarming locusts, do you also know how to reverse it?”

”Reverse it?”

”Yes. Since you caused the transformation... isn’t there a way to turn them back?”

He must’ve figured that if I knew how to make the change, I might also know how to undo it. But unfortunately, that just wasn’t possible.

Once a locust becomes a swarming locust, there’s no going back.

Even in my past life, the only way to deal with them was mass extermination—usually with pesticides.

”No. Once a green locust transforms into a swarming locust, there’s no reversing it.”

”...I see.”

He nodded quietly. His response was restrained, but something about it felt deeply emotional.

I asked carefully.

”Is there... a story behind that, Elder? You sound...”

”Ah... it’s nothing. I’ve retired now, but I still worry about my people.”

”By people, you mean... the Beggars’ Guild?”

”Yes. That’s right.”

He was worried about locusts because of the Beggars’ Guild?

It wasn’t like beggars farmed land. Wasn’t that a little overdramatic?

It reminded me of that old parable from the Spring and Autumn period—“A man of Qi fears the sky will fall.” Worrying about something totally beyond one’s control.

Kind of like an unemployed guy stressing over celebrity scandals in the modern world.

I guess my face gave away what I was thinking, because Elder Geolhwang chuckled and spoke with a knowing smile.

”You’re thinking, ‘What do beggars have to do with locusts and farming?’ Aren’t you?”

”N-no, of course not! Even the Beggars’ Guild can worry about the country... or locusts... I mean, why not?”

Was Elder Geolhwang secretly a mind reader? Did reaching his level of martial mastery unlock clairvoyance?

I waved my hands and tried to play it cool, but he laughed heartily and said:

**”Hahaha, you’re too easy to read. But it’s not unreasonable to think that way. Still, there’s a good reason why we beggars worry about swarming locusts. When famine or locust plagues strike, the ones who starve to death first and most often... are Beggars’ Guild members. Charity only flows when people have enough to spare. And when they don’t even have food for themselves, who do you think gives to beggars? That’s why we worry.”**

Once he said it, it made perfect sense.

People can only donate when they have something to give. No one’s going to feed a beggar if they can’t even feed their own family.

So when drought or locusts hit... of course, the beggars die first.

It’s just like in my past life—when the economy crashed, people cut hobbies and luxuries first. The less food there is, the fewer people willing to give any away.

”Ah... yes, that makes a lot of sense.”

I nodded, accepting his words.

Then, Elder Geolhwang lowered his voice slightly and asked me quietly:

”So... since you clearly understand swarming locusts well, can you predict how fast they’ll multiply? Or where they’ll migrate?”

”Hmm... I can’t give perfect predictions, but I can make decent guesses.”

If I checked things like the adult-to-nymph ratio in a swarm, wind direction, and population density, I could more or less track their behavior.

I nodded, and the Elder asked again in a careful tone:

”Then... would you be willing to take on a job for me?”

”A job?”

**”Yes. As I said, the thing the Beggars’ Guild fears most is drought and locusts. That’s why we always monitor any sign of either.

Lately, word has come that swarming locusts have been drifting in and out of Tianzhu, approaching from the west, near the Tibet region.

I was wondering if you could go investigate—see whether they’re truly moving toward the Central Plains, and if so, in what direction.”**

It was an important mission, and I did want to help.

But... there was a problem.

”I’d love to help, but... I’m kind of under partial house arrest by my clan at the moment.”

Because of the upcoming wedding, I was still half-confined to the Tang estate.

As I explained this, Hwa-eun gave me a small smile—clearly pleased with my answer.