First in Nagano Prefecture: Rare 'Hosonakabosotamamushi' Beetle Habitat Confirmed in Saku City — Special Exhibition Launched by Joint Research from Parada Insect Experience Learning Hall and Director Mamoru Watanabe

Sakudaira Oyama Development Co., Ltd. (Headquarters: Saku City, Nagano Prefecture; President: Susumu Washio), operator of the Parada Highway Oasis, announces that Mamoru Watanabe (Watanabe Mamoru), director of the Insect Experience Learning Hall it manages and operates, has discovered a new habitat of the rare buprestid beetle 'Hosonakabosotamamushi' through collaborative research. This research has been published in Sayabane New Series No. 59, the Japanese-language journal issued by the Japanese Society of Coleopterology. The Insect Experience Learning Hall is now hosting a special exhibition to publicly share this academic achievement.

Insect Experience Learning Hall

Overview of Research Findings

This study was conducted as joint research between beetle researcher Mr. Wataru Yamada (Atsugi City, Kanagawa Prefecture) and Director Mamoru Watanabe of our facility.

1. Identification of New Habitats (Saku City and Komoro City) for an Endangered Species

As a result of meticulous surveys conducted between June 5, 2017, and June 10, 2024, the presence and collection of 'Hosonakabosotamamushi'—a species previously recorded only in extremely limited areas such as Yamanashi Prefecture (Mitsutoge), Nagano Prefecture (Matsumoto City and Ueda City), and Oita Prefecture (Beppu City)—was successfully confirmed in Shimooyama, Saku City, and Takihara, Komoro City. This represents a highly valuable additional record (new locality) within Nagano Prefecture.

2. Clarification of External Characteristics for Sex Identification (Male vs. Female)

In this paper, we conducted an in-depth examination of 'sexual dimorphism,' a feature previously not thoroughly discussed in related species. Through external morphological observations, we provide detailed explanations of clear distinguishing features for identifying males and females by appearance, including the condition of setae on the prosternum, the shape of the terminal abdominal sternites, and the arrangement of spines on the inner side of the hind tibia.

Comment from Discoverer and Co-Author: Mamoru Watanabe, Director of the Insect Experience Learning Hall

"This research began when Mr. Yamada, the first author, found a photo of a jewel beetle I had posted on social media (online) and contacted me. That connection sparked our joint ecological survey, and after conducting detailed fieldwork around Mount Oyama, I am delighted that we were able to report a new habitat for this rare species.

The Hosonakabosotamamushi depends on a plant called 'Nawashiroichigo' (Rubus palmatus) for survival. While this plant grows commonly in everyday environments, this beetle species has a dark body color and lives on leaves near the ground, making it highly likely to have been overlooked until now. This announcement demonstrates that even in our immediate surroundings, valuable ecosystems may be hidden in plain sight.

Following publication in the academic journal, we have successfully created an opportunity to present the actual specimens and research findings to the public as planned. I sincerely hope many people, especially children who will carry the future of science, will visit and appreciate the wonders of Saku City's natural environment and the boundless potential (room for growth) hidden within our region."

Research paper published in the academic journal (top), and the newly opened special exhibition space at the Insect Experience Learning Hall (bottom). The newly installed special display case for 'Hosonakabosotamamushi,' accompanied by panels explaining the discovery and scientific details.

Special Exhibition: Commemorating the Research Publication

To commemorate the publication of the research paper and the success of the study, the Insect Experience Learning Hall has set up a special exhibition corner featuring the rare 'Hosonakabosotamamushi' specimens collected during the survey, along with explanatory panels that visually illustrate the differences between males and females.

Exhibition Location: Inside the Insect Experience Learning Hall at Parada Highway Oasis, Sakudaira

Exhibition Contents:

- Display of 'Hosonakabosotamamushi' specimens collected in Saku City and Komoro City

- Explanatory panels comparing sexual dimorphism (e.g., hair length, prosternal spine shape) using microscope images

- Ecological explanations about the collection sites, including 'Nawashiroichigo' plant colonies

Facility and Operator Overview

Operator: Sakudaira Oyama Development Co., Ltd.

Representative: President Susumu Washio

Facility Name: Insect Experience Learning Hall at Parada Highway Oasis, Sakudaira

Address: 2681 Shimooyama, Saku City, Nagano Prefecture 385-0003

Business Hours: 9:30 AM – 5:00 PM

Official Website: https://www.saku-parada.jp/

【For Media Inquiries: Contact Information】

※ For interviews, press coverage, or filming at the exhibition space, please contact the following:

Organization/Facility: Insect Experience Learning Hall, Parada Highway Oasis, Sakudaira

Contact: Director Mamoru Watanabe (Watanabe Mamoru)

Phone Number: 0267-68-1111

Email Address: [email protected]