Third expedition of researchers from the National Museum of Natural History, Sofia to Northern Vietnam

Between 6th and 25th October 2025, the third joint scientific expedition of researchers from the National Museum of Natural History, Sofia (NMNHS), the Institute for Biodiversity and Ecosystem Research (IBER), the Regional Museum of Natural History, Plovdiv (RMNHP), and Vietnamese zoologists was conducted. For the first time, a researcher from the Virginia Museum of Natural History, Martinsville also joined the field studies, significantly expanding the partnership both in terms of research and institutions. The research expedition for 2025 was organised following an invitation by Assoc. Prof Dr Pham Hong Thai and was financed with the help of all guest institutions, as well as with support from the Bulgarian Ministry of Education and Science as part of the National program “Young Researchers and Postdocs — 2,” approved with DCM 206/07.04.2022, and from “Kaufland Bulgaria Ltd. and Co” KG.

The expedition included both established specialists and young researchers — Assoc. Prof Dr Rostislav Bekchiev, Assoc. Prof Dr Nikolay Simov and Assoc. Prof Dr Mario Langourov (NMNHS), Assoc. Prof Dr Ivailo Dedov (IBER), Dr Kaloyan Ivanov (Virginia Museum of Natural History), Dr Svetlozara Kazandzhieva (NMNHS, RMNHP), Sen. Assist. Dr Ognyan Todorov (RMNHP, Paisii Hilendarski University Plovdiv), and Kristian Vladov (RMNHP), whose successful cooperation contributed to the expedition’s great results.

From Vietnam, Assoc. Prof Dr Pham Hong Thai, Director of the Mientrung Institute for Scientific Research (MISR) and Deputy Director of the Vietnam National Museum of Nature (VNMN) with the Vietnam Academy of Science and Technology (VANT), as well as the young researcher Trung Vu Manh (VNMN) both took part in the organisation and execution of the fieldwork. The aim of this expedition was to continue and build on results from previous field studies in 2018 and 2023, which laid the foundations of a deeper study into the invertebrate fauna of Northern Vietnam and an expansion of the knowledge regarding species diversity in the region.

The three weeks of fieldwork included studies of various habitats in the Sa Pa region — the areas around two impressive waterfalls (Love Waterfall, Silver Waterfall), the highest peak of Indochina — Fansipan (3143 m), and the traditional village Cat Cat. Additional studies were also conducted in the region Dien Bien Phu, around the Pa Khoang lake — a region with high significance for conservation, yet completely lacking in entomological research.

The studies dealt with a wide spectrum of invertebrates — beetles (Coleoptera), flies (Diptera), true bugs (Hemiptera), Hymenoptera, gastropods (Gastropoda), and butterflies (Lepidoptera). The entire range of collection methods was used for sample collection — from classical entomological bags, litter sampling, and shaking branches to Malaise traps, pitfall traps, MSS traps, flight interception traps, insecticide knockdown methods, and blacklight traps.

The materials collected during the first two expeditions led to the identification and description of a series of new and previously unknown to science species of beetles, snails, true bugs, flies, and barklice. Published new species include Pselaphodes fansipanensis Bekchiev & Yin, 2019, Lathrobium sapaensis Tokareva & Bekchiev, 2025, Laocaia simovi Dedov & Schneppat, 2019, Muangnua vumanhi Dedov, 2024, Cambodiparmarion bekchievi Dedov & Vu, 2025, Ostracolethe penevi Dedov & Vu, 2025, Stenopsocus beroni Georgiev & Quang-Manh, 2024, S. tamdaoi Georgiev & Quang-Manh, 2024 and Chalastonepsia vumanhi Kazandzhieva, 2025. The material collected during systematic research allows us to enrich our knowledge of the Vietnamese fauna, as well as conduct large-scale genetic analysis and consequently describe new species.

The results of the three expeditions were recently presented at two international scientific conferences — Balkan.Bio (30—31.10.2025) and “VIETNAM UP CLOSE: Heritage, Continuity, Future” (13—15.11.2025).

Research will continue over the next two years (2026—2027) thanks to the approved project “Biodiversity of insects in Bach Ma National Park (Central Vietnam) — new approaches and methods for field research” (IC-VT/03/2026—2027) with the dual cooperation of BAS and the Vietnam Academy of Science and Technology. This will also expand the area of research up to Central Vietnam, specifically the Bach Ma National Park.

The novel scientific discoveries will contribute to our greater understanding of the biodiversity of one of the most species-rich regions in Southeast Asia and aid the efforts to preserve this invaluable natural resource.