Meet Jo Nagai: 10-year-old Japanese student who discovered butterflies can remember their time as caterpillars after he noticed that the caterpillars he had raised to recognise him after turning into butterflies

A remarkable discovery by 10-year-old Japanese student Jo Nagai is challenging long-held scientific assumptions about insect memory. Jo, an elementary school student from Kobe, has conducted research suggesting that butterflies can retain memories formed during their caterpillar stage, even after undergoing complete metamorphosis.

Jo's fascination with insects began in early childhood. While raising Asian swallowtail butterflies, he observed that butterflies he had raised often returned to his hand after release, unlike wild butterflies that typically flew away. This led him to question whether memories from the caterpillar phase could survive the dramatic transformation into a butterfly.

To test his hypothesis, Jo designed a series of experiments. He exposed swallowtail caterpillars to a lavender scent combined with mild vibrations. After metamorphosis, he used a Y-shaped maze to test the adult butterflies. His findings indicated that approximately 70% of the butterflies avoided the lavender scent, suggesting they remembered the association formed during their larval stage.

These observations contradict the traditional scientific view that an insect's nervous system is completely reorganized during the pupal stage, effectively erasing all previous memories. Jo Nagai's work, which has been presented to professional scientists, is generating significant discussion about animal cognition and the complexities of metamorphosis. While some findings await independent verification, his research has earned him international recognition at a young age. Despite this scientific acclaim, Jo aspires to become a veterinarian, underscoring his lifelong passion for animals and nature.