Signal Hill: Caterpillar Roadshow

Radiolab

Published: Fri Apr 11 2025

A couple years ago, an entomologist named Martha Weiss got a letter from a little boy in Japan saying he wanted to replicate a famous study of hers. We covered that original study on Radiolab more than a decade ago in an episode called Goo and You – check it out here – and in addition to revealing some fascinating secrets of insect life, it also raises big questions about memory, permanence and transformation. The letter Martha received about building on this study set in motion a series of spectacular events that advance her original science and show how science works when a 12-year-old boy is the one doing it. Martha’s daughter, reporter Annie Rosenthal, captured all of it and turned it into a beautiful audio story called “Caterpillar Roadshow.” It was originally published in a brand new independent audio magazine called Signal Hill, which happens to have been created in part by two former Radiolab interns (Liza Yeager and Jackson Roach, both of whom worked on this piece), and we...

Summary

Radiolab Episode Summary: "Signal Hill: Caterpillar Roadshow"

Release Date: April 11, 2025
Hosts: Lulu Miller and Latif Nasser
Produced by WNYC Studios

Introduction

"Caterpillar Roadshow," a segment from Radiolab's audio magazine Signal Hill, delves into an extraordinary correspondence between Annie Rosenthal, an accomplished entomologist, and Joe Nagai, an exceptionally gifted second-grader from Japan. This story intertwines themes of scientific curiosity, cross-cultural friendship, and the profound impact of mentorship.

The Beginning of a Unique Correspondence

In April 2022, Annie Rosenthal received an unexpected letter from Joe Nagai, an 8-year-old student from Kobe, Japan. Unlike the typical fan mail her mother, Martha Weiss—an esteemed entomologist—received, Joe's letter was both earnest and scientifically inquisitive.

Joe Nagai [02:58]: "Hello. Nice to meet you. My name is Joe Nagai. I'm from Japan. I live in Kobe, Japan. I'm in the second grade at Ibuki Elementary School. When I found your research on the Internet, I was so delighted."

Joe's fascination stemmed from Martha Weiss's research on moths, particularly the groundbreaking discovery that "an adult moth could remember something it learned as a caterpillar"—a phenomenon where memories persist through metamorphosis.

Replicating Groundbreaking Experiments

Inspired by Martha's work, Joe embarked on his own experiments to determine if his swallowtail butterflies retained memories from their caterpillar stage. Despite his young age, Joe meticulously adapted the complex methodologies used in professional research to suit his home laboratory setup.

Joe Nagai [04:10]: "I think it's amazing that a caterpillar can have an experience, go into its chrysalis five weeks pass, emerge as a seemingly different organism, and that it still can recall experiences that happened to it when it was a caterpillar."

Joe's dedication led him to develop a simpler approach for his experiments, focusing on color association rather than the more intricate smell-and-shock methods used by Martha and her graduate student, Doug Blackiston.

Building a Scientific Friendship

Over the summer, Annie and her family engaged in a burgeoning pen-pal relationship with Joe. Their exchanges were rich with scientific dialogue, mutual respect, and a shared passion for entomology. Joe's persistence and genuine curiosity not only impressed Annie but also inspired her and her family.

Joe Nagai [06:59]: "Everybody becomes more interested in each other than the bugs, which is good because it helps ourselves species persist."

Recognizing Joe's potential, Annie's family, including her father Josh, became enthusiastic supporters of Joe's scientific endeavors, discussing his findings and anticipating his future contributions to the field.

The Invitation to Japan

In the spring of 2023, Joe took his research a step further by exploring epigenetics—the study of how experiences can influence gene expression across generations. His latest experiment aimed to determine if memories could be inherited by the next generation of butterflies.

Joe Nagai [12:05]: "It had never occurred to me to even ask that question."

This ambitious project caught the attention of the international entomological community, leading Joe to present his findings at prestigious universities in Japan. His remarkable achievements culminated in an invitation to the International Congress of Entomology (ICE) 2024 in Kyoto.

Meeting Joe in Japan

Annie and her family accepted Joe's invitation, embarking on a journey to Japan that would solidify their cross-cultural friendship. Upon arrival, they were greeted by Joe's mother, Sari Nagai, and his older brother, Hayato. The meeting was a blend of scientific collaboration and personal connection, set against the vibrant backdrop of Tokyo's insect-enthusiast culture.

Sari Nagai [29:08]: "Yeah. I'm Joe."

Throughout their visit, Annie observed Joe's dedication firsthand—from his hands-on experiments to his interactions with fellow young scientists. The highlight was Joe's presentation to the Crown Prince of Japan, where his eloquence and scientific acumen shone brightly.

Validating Scientific Findings

Despite Joe's impressive results, Annie's mother insisted on rigorous scientific validation. Together, they meticulously reviewed Joe's data to ensure the integrity and reliability of his findings.

Joe Nagai [45:15]: "I care about Joe."

This collaboration underscored the importance of mentorship and the nurturing of young scientific minds. By scrutinizing Joe's work, they aimed to contribute meaningful insights to the field of entomology, particularly in understanding memory inheritance in butterflies.

Reflections and Impact

The story of Joe Nagai and Annie Rosenthal's collaboration highlights the power of curiosity and cross-generational mentorship in scientific discovery. Joe's unwavering dedication as a child prodigy and Annie's supportive guidance exemplify how passion and support can lead to groundbreaking research, even across continents and cultural barriers.

Annie Rosenthal [42:23]: "Compassionate. And treat them as if they feel pain and try to minimize any pain or suffering while getting our science done."

This episode not only celebrates scientific achievement but also emphasizes the human connections that drive innovation and discovery. Joe's journey from a young enthusiast to a respected researcher serves as an inspiration for aspiring scientists worldwide.

Conclusion

"Caterpillar Roadshow" is a testament to the extraordinary possibilities that emerge when young minds meet experienced mentors. Through meticulous correspondence and shared scientific pursuits, Annie Rosenthal and Joe Nagai bridged geographic and generational divides, fostering a partnership that promises to leave a lasting mark on the world of entomology.

Notable Quotes:

Annie Rosenthal [03:44]: "What's your feeling like coming out of this?"
Joe Nagai [05:37]: "But I want to try to find if a swallowtail butterfly could remember what it learned as a caterpillar."
Joe Nagai [45:15]: "I hope so. But the other reason that it matters is because I care about Joe."

This summary captures the essence of the "Caterpillar Roadshow" episode, focusing on the compelling narrative of scientific exploration and the unique bond formed between Annie Rosenthal and Joe Nagai.