Key Facts
• Late July 2025: 64mm wild giant stag beetle found in Karatsu, Saga Prefecture.
• Captured by Takuya Kubota, 49, a self-employed insect enthusiast from Ochi Town.
• Stag beetle nicknamed ‘Black Diamond’ during its popularity boom decades ago.
• Wild stag beetles over 60mm are considered large; typical size ranges from 27–77mm.
• Found on July 30, 2025, during the day on a sawtooth oak tree.
• Captured at 9:30 PM after careful extraction using two tools.
• Specimen shows no signs of captivity, suggesting it is a first-year adult.
• Karatsu and Higashi-Matsuura areas had no prior records of wild stag beetles.
• Decline attributed to habitat loss, overharvesting, and a 20-year popularity boom.
• Stag beetles are now classified as Endangered Category II by Japan’s Ministry of the Environment.
• Kubota has been breeding and selling beetles for 20 years, promoting nature conservation.
Summary
A 64mm wild giant stag beetle, once dubbed the ‘Black Diamond,’ was discovered in Karatsu, Saga Prefecture, in late July 2025. Captured by Takuya Kubota, a local insect enthusiast, this rare find marks the first recorded sighting in the Karatsu and Higashi-Matsuura regions. The beetle, considered large for its species, shows no signs of captivity, suggesting it is a first-year adult. Stag beetle populations have significantly declined due to habitat loss and overharvesting during a 20-year popularity boom. Kubota, who has been breeding and selling beetles for two decades, emphasizes the importance of preserving natural habitats to sustain wildlife. The discovery highlights the need for continued conservation efforts as stag beetles remain classified as Endangered Category II in Japan.
