08/18/2026
Jo Nagai, a 10-year-old student from Kobe, Japan, has attracted attention for his fascinating research into butterfly memory. His interest began with Asian swallowtail butterflies that he raised at home. Jo noticed something unusual: butterflies he had raised as caterpillars seemed to recognise him even after transforming into adults. This observation made him wonder whether memories formed during the caterpillar stage could survive metamorphosis, the dramatic biological transformation from caterpillar to butterfly.
Jo, a student at Ibuki East Elementary School, spent years observing insects and recording their behaviour. His curiosity eventually developed into a series of experiments designed to explore whether butterflies could retain learned associations after metamorphosis. According to the report, his work has been presented to professional scientists and has generated discussion about insect cognition, memory and metamorphosis.
For his experiments, Jo exposed swallowtail caterpillars to the smell of lavender while also applying a mild vibration stimulus. After the caterpillars transformed into butterflies, he tested the adults using a Y-shaped tube maze. His findings reportedly showed that around 70% of the adult butterflies avoided the lavender scent. Jo interpreted this as evidence that some form of memory from the caterpillar stage may have survived metamorphosis.
The research also explored whether the behaviour could appear in later generations. Jo reported that offspring and even grandchildren of conditioned butterflies showed an increased tendency to avoid lavender despite never being exposed to the original conditioning. He suggested that transgenerational epigenetic inheritance might help explain the observation. However, the report stresses that this interpretation remains preliminary and requires independent scientific research before it can be considered established evidence.
Jo's work has received interest because scientists are increasingly studying how memories and learned behaviours might persist through metamorphosis. His research was presented at scientific meetings, including the International Congress of Entomology in Kobe. However, it has not yet been published in a peer-reviewed scientific journal, meaning independent researchers still need to replicate and assess the findings.
The story has also gained widespread attention online because of Jo's age and dedication. He reportedly produced a detailed 33-page research paper and presented his findings before experienced scientists. His work has inspired many people by showing how simple observations can lead to interesting scientific questions.
If future studies confirm his observations, Jo's research could contribute to scientists' understanding of insect memory, metamorphosis and the possible transmission of learned behaviours between generations. More broadly, his story demonstrates how curiosity, patience and careful observation can encourage young people to explore science.
