SearchResearch Challenge (10/8/25): How can the same locust look so different?

It's difficult to understand... 

Rocky Mountain locust. P/C Wikimedia

... how variable the appearance of an animal might be.  

Sure, people look very different around the globe, and both dogs and cats have wildly variable appearances.  But in every case, you'd say that they're all of one species. 

So how could biologists mistake the two different looks of a locust for two different species?  

A bit of background here.

I've been reading Jeffrey A. Lockwood's brilliant book Locust: the devastating rise and mysterious disappearance of the insect that shaped the American frontier. (Basic Books, 2009.) 

Part of the book tells the story of the Locust Plague of 1874.  Locusts swarmed over an estimated 2,000,000 square miles (5,200,000 square kilometers) of the plains states in North America, causing millions of dollars' worth of damage. 

Residents described swarms so thick that they covered the sun for up to six hours. The swarms of Rocky Mountain locusts (Melanoplus spretus) were larger than the state of California and comprised some 12.5 TRILLION insects.

They would eat grass, trees, even the clothes off people's backs.  

But less than 30 years later, the entire species was extinct. Gone.  Vanished.  

That's the subject of Lockwood's book--how is it possible for such a vast number of insects to simply disappear?  

A cartoon of the locusts arriving in Nebraska

Laura Ingalls Wilder’s book, On the Banks of Plum Creek  has a description of what it was like to live through the literal plague of locusts arriving on the farm:  

Plunk! something hit Laura's head and fell to the ground. She looked down and saw the largest grasshopper she had ever seen. Then huge brown grasshoppers were hitting the ground all around her, hitting her head and her face and her arms. They came thudding down like hail. 

The cloud was hailing grasshoppers. The cloud was grasshoppers. Their bodies hid the sun and made darkness. Their thin, large wings gleamed and glittered. The rasping whirring of their wings filled the whole air and they hit the ground and the house with the noise of a hailstorm.

You might think of this extinction as the most spectacular “success” in the history of economic entomology — the only complete elimination of an agricultural pest species.  But it seems as if it was a total accident.  

(For all the details, I encourage you to read Lockwood's book--a fascinating detective story of a past extinction. Also check out the Wiki articles Locust Plague of 1874 and Rocky Mountain locust. For more details, Lockwood has a short article about his sleuthing, The Death of the Super Hopper.)  

But that's not our Challenge for this week.  Instead, I want to focus on that first question I raised earlier--So how could biologists mistake the two different looks of a locust for two different species?  

1. How often has it happened that biologists have seen two (or more) species when it was really just one in different clothing?  Can you find another case of two (or more) species being reconciled into one? 

2. It's clear that organisms can have multiple shapes / patterns / colors (we've discussed this before in the context of plant mimicry).  Can you find an organism that has a huge number of different appearances?  Any idea WHY they have such variability?  

It's fascinating stuff--hope you enjoy reading about it as much as I did.  

Be sure to tell us HOW you found the answers to this week's Challenge.  Regular search?  AI?  If so, what prompts did you use... and how well did it work for you?  

We want to hear about successes as well as disasters! 

Keep searching.