Catalogue of the type specimens of the family Hydrometridae (Insecta, Hemiptera, Heteroptera) in the Natural History Museum Vienna

Catalogue of the type specimens of the family Hydrometridae (Insecta, Hemiptera, Heteroptera) in the Natural History Museum Vienna Herbert Zettel1, Harald Bruckner1 1 2nd Zoological Department, Natural History Museum Vienna, Burgring 7, 1010 Vienna, Austria https://zoobank.org/9341A536-3791-40B8-A08F-971AC859AE2E Corresponding author: Herbert Zettel ([email protected]) Academic editor:Sabine Gaal-Haszler ♦ Received 4 March 2024 ♦ Accepted 17 April 2024 ♦ Published 10 November 2025 Abstract The type specimens of the gerromorphan family Hydrometridae housed in the Natural History Museum Vienna are catalogued. Information on type status, label data, and current taxonomic status is provided. The treated type material consists of 92 specimens of ten nominal taxa of species and subspecies, including three holotypes and 89 paratypes (including two allotypes). Photographs of the three holotypes are provided. Key Words Hydrometridae, types, catalogue, collection Introduction This type catalogue continues a series dealing with the families Gerridae and Hebridae of the Gerromorpha (Zettel et al. 2022, 2023). In contrast to the collections of Gerridae and Hebridae, the Natural History Museum Vienna holds only a relatively small collection of Hydrometridae, chiefly from the Oriental Region. There are a few historical specimens, some that were described (in cooperation) by the current curator, and some others acquired by exchange from other taxonomists. General information on the museum’s Heteroptera collection was provided in the type catalogues of Reduviidae (Sehnal 2000) and Gerridae (Zettel et al. 2022). Materials and methods The source of this inventory is the database of the Natural History Museum Vienna, which includes all types of Hydrometridae in the systematic main collection registered until 2022. All type specimens are dry mounted. The species are listed alphabetically. In most cases (except two), the original combination is still valid. The paragraph with the original citation includes the type locality and the depository of the holotypes. If the type depository is not mentioned in the original description, it was taken from an unpublished catalogue by Nils Møller Andersen, or investigated by the authors. If paratypes originate from more than one locality, a “type region” summarizes the distribution of all type specimens. Acronyms of depositories of primary types BORN Museum Borneensis, Institute for Tropical Biology and Conservation, Uni versiti Malaysia Sabah, Malaysia NHMW Natural History Museum Vienna, Austria SEMC KU Biodiversity Institute (formerly Snow Entomological Museum Collection), Kansas University, Lawrence, Kansas, U.S.A. UMC University of Missouri, Columbia, U.S.A. USNM National Museum of Natural History, Washington D.C., U.S.A. ZRC Zoological Reference Collection, Lee Kong Chian Natural History Museum, National University of Singapore, Singapore ANHMW 126 2025, 65–70 DOI 10.3897/anhmw.169056 Copyright Herbert Zettel & Harald Bruckner. This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. anhmw.pensoft.net Herbert Zettel & Harald Bruckner: Catalogue of the Hydrometridae types in the Natural History Museum Vienna66 The types are listed by providing specific collection numbers (# followed by persistent identifier number). Locality labels are cited in quotation marks. The sign \ indicates a line break. Corrections and translations from German are occasionally added in square brackets. A paragraph “Current status” is only added if it deviates from the original taxon. Many illustrations were already published in the original publications, and dorsal habitus views of Hydrometridae are only of very limited use. Therefore, we restrict new photos to the holotypes. Stacked photos were taken with a Leica DFC490 camera attached to a Leica Z16APO optics carrier, using Leica Application Suite V3.8, then stacked with ZereneStacker 64-bit, and processed with Adobe Photoshop 7.0. Results Catalogue Hydrometra akekawati Sites & J. Polhemus, 2003 Hydrometra akekawati Sites & J. Polhemus, 2003: 140. Type locality: Thailand, Chaiyaphum Province, “Amphur Khon Sarn Tumbon Heuy Yang”; holotype in UMC. Type material. Paratypes (1 brachypterous male, #12467; 1 brachypterous female, #12468): “THAILAND: Chaiyaphum Prov.\ Amphur Khori Sam [Sarn]; Tumbon\ Ban Tong Loei Lai; veg. pond\ on Hwy 2055, 7.4 km S of\ Hwy 21; 2 July 1998; L-228\ Vitheepradit & Sawangsak”. Current status. Hydrometra okinawana Drake, 1951 (synonymized by Yang and Zettel 2005). Notes. There is a discrepancy between the published type locality in Sites and Polhemus (2003) and the label text (see above). After being inquired by the first author of the present paper about the accurate locality, Robert W. Sites (pers. comm., 2023) answered: “This collection was before we used GPS coordinates to mark localities. … The best I can do for L-228 is locate Amphur Khon Sarn, which is the northernmost district in Chaiyaphum Province. ... So we were collecting in Phetchabun Prov., then three localities in Chaiyaphum Prov., then back to Phetchabun. So, the Chaiyaphum collections (L-226, 227, and 228) must have been in the western part of Amphur Khon Sarn. L-228 was the third collection of the day in Chaiyaphum Province and was followed later in the same day with a collection site (L-229) in Phetchabun Province, so it makes sense that it was close to the border with Phetchabun Province. Unfortunately, I cannot find anything resembling Tumbon Ban Ton Leoy Lai on my maps. So, the best I can do is Amphur Khon Sarn (sometimes spelled as one word: Khonsarn or Khonsan).” Hydrometra balkei Zettel, 2013 Figs 1, 2A, B Hydrometra balkei Zettel, 2013: 14. Type locality: Indonesia, Central Papua Province, swamp near Nabire, Kali Bobo, 3°27'S, 135°27'E; holotype in NHMW. Type material. Holotype (apterous male, #12736) and paratypes (2 apterous females, #12737, 12738) “INDONESIA, Irian Jaya\ swamp nr. Nabire, Kali\ Bobo, 3°27'S, 135°27'E\ 5 m, IV.1998, leg. M. Balke”. Hydrometra borneensis Zettel & Yang, 2004 Hydrometra borneensis Zettel & Yang, 2004: 391. Type locality: Malaysia, Sabah, Sandakan, Kampong Batu Putih, Sg. Kinabatangan, ca. 5°54'N, 118°03'E; holotype in BORN. – Type region: East Malaysia: Sabah, Sarawak; Brunei; Indonesia: Kalimantan. Type material. Paratypes (15 brachypterous males, #11276–11290, 10 brachypterous females, #12291– 12300) “MALAYSIA: Sarawak\ Kelabit Highland[s]\ 1000–1200 m, (11)\ Bareo - Arur Dalam\\ Tümpel auf Weiden u.\ Reisfelder [= ponds on pastures and paddy fields] 26.2. -\ 1.3.1993\ leg. H.Zettel”; paratypes (1 macropterous male, #11301; 1 brachypterous male, #11302) “MALAYSIA: Sabah\ Sandakan, Danau Biandung\ Bosar, Sg. Kinabatangan\ 11.IV.1994, leg.\ H.K. Lua & C.Y. Chang”; paratypes (1 brachypterous male, #11303; Figure 1. Hydrometra balkei, holotype, male (#12736), habitus. Annals of the Natural History Museum Vienna 126 2025, 65–70 anhmw.pensoft.net 67 1 macropterous male, #11304; 1 brachypterous female, #11305; 1 macropterous female, 11306) “MALAYSIA: Sabah\ Sandakan, Kg. Balu Putih\ Sg. Kinabatangan, SAPODA\ 7.IV.1994, leg.\ H.K. Lua & C.Y. Chang”. Hydrometra brevitarsus Zettel & Yang, 2004 Hydrometra brevitarsus Zettel & Yang, 2004: 389. Type locality: Singapore, MacRitchie Forest, ca. 1°21'N, 103°49'E; holotype in ZRC. – Type region: Singapore; West Malaysia: Johore, Pahang, Perak; East Malaysia: Sarawak; Indonesia: Pulau Batam, Sumatra. Type material. Paratypes (2 apterous males, #11307, 11308; 2 apterous females, #11309, 11310): “INDONESIA: Sumatra\ Jambi, Darkie Water\ Reserve, 6.VI.1996\ leg. Tan H.H. THH9644”. Hydrometra heoki heoki Zettel & Yang, 2004 Hydrometra heoki heoki Zettel & Yang, 2004: 393. Type locality: East Malaysia, Sarawak, near Kampung Matang, Kampung Temenggong, ca. 1°37'N, 110°13'E; holotype in ZRC. – Type region: East Malaysia: Sabah, Sarawak; Indonesia: Kalimantan Tengah, Kalimantan Timur, Kalimantan Barat. Type material. Paratypes (3 brachypterous females, #32220–32222): “MALAYSIA: Sarawak\ Kelabit Highland[s]\ 1000–1200 m, (12)\ Bareo, Pa’Ukat\\ Bachufer [stream side] \ 27.2.1993”; paratype (1 brachypterous male, #32223): “MALAYSIA: Sabah\ Danum Valley, Sapat\ Kalisan, 12.2.1997\ leg. H. Zettel (15)”; paratypes (1 brachypterous male, #32224; 1 brachypterous female, #32225): “MALAYSIA: Sabah\ Danum Valley, Palum\ Tambun, 7.-12.2.1997\ leg. Zettel et al. P 24”; paratype (1 brachypterous male, #32226): “MALAYSIA: Sabah\ Danum Valley, Palum\ Tambun, 7.-12.2.1997\ leg. Zettel & al. P 88); paratypes (3 brachypterous females, #32227–32229; 3 brachypterous males, #32230– 32232): “INDONESIA: Kalimantan\ Barat, Kabupaten Sanggau\ abt. 249 km to Pontianak\ on Sosok-Sanggau Rd.\ 26.IV.1998 LHK 382”; paratypes (1 brachypterous female, #32233; 1 brachypterous male, #32234): “MALAYSIA: Sarawak\ Kg. Temenggong, nr.\ Kg. Matang, 4 Sep.\ 1995, leg. H.H. Tan”; paratypes (1 brachypterous male, #32235; 1 brachypterous female, #32236): “MALAYSIA: Sarawak\ Sg. Stuum Muda, nr.\ Lundu ferry point at\ Bg. Kayan, 2 Sep.1996\ leg.. H.H. Tan & S.H. Tan”; paratypes (2 brachypterous males, #32237, 32239; 2 brachypterous females, #32238, 32240): “MALAYSIA: Sabah\ Danum, Sg. Bilong\ 3 Oct. 1996\ leg. H.H. Tan & Y.Y. Goh”. Figure 2. Hydrometra balkei, holotype, male (#12736). A. Anterior portion of head, dorsal view, illustrating clypeus; B. Sterna and genital capsule, ventral view. anhmw.pensoft.net Herbert Zettel & Harald Bruckner: Catalogue of the Hydrometridae types in the Natural History Museum Vienna68 Hydrometra heoki paya Zettel & Yang, 2004 Hydrometra heoki paya Zettel & Yang, 2004: 396. Type locality: West Malaysia: Johor, Mersing, ca. 2°26'N, 103°49'E; holotype in ZRC. Type material. Paratypes (2 brachypterous males, #11403, 11404): “WEST MALAYSIA: Johor\ Mersing, Sg. Selangi\ 22.IV.1992, leg. Yeo KL\ & Chang CY YKL7921”. Paratype (1 brachypterous female, #11405): “Malaysia, Johor\ Km.56 to Mersing\ Coll:H.H.Tan et.al\ 25Mar.1998, THH9826”. Paratype (1 brachypterous female, #11406): “WEST MALAYSIA: Johor\ Mersing, stream at km 31\ to Mersing, 11.III.1998\ leg. H.H.Tan et al. (THH9820)”. Hydrometra insularis Hungerford & Evans, 1934 Fig. 3A–C Hydrometra insularis Hungerford & Evans, 1934: 76. Type locality: Indonesia, “West Sumatra”; holotype in NHMW. – Type area: Indonesia: Sumatra, Java. Type material. Holotype (1 brachypterous male, #32242), allotype (macropterous female, #32243), and paratypes (3 brachypterous males, #32244–32246; 3 brachypterous females, #32247–32249; head missing in #32246 and 32248): “W-Sumatra\ Fruhstorfer”. Current status. Hydrometra orientalis Lundblad, 1933 (synonymized by J. Polhemus and Reisen 1976: 284). Hydrometra maidli Hungerford & Evans, 1934 Fig. 4 A–C Hydrometra maidli Hungerford & Evans, 1934: 73. Type locality: Indonesia, “West Sumatra”; holotype in NHMW. Type material. Holotype (1 brachypterous male, #11389), allotype (brachypterous female, #11390) and paratypes (3 brachypterous females, #11391– 11393, 1 brachypterous ex., #11394; head missing in #11391, abdomen missing in #11394): “W-Sumatra\ Fruhstorfer”. Figure 3. Hydrometra insularis, holotype, male (#32242; terminalia of abdomen missing). A. Habitus, dorsal view; B. Abdominal segments, lateral view; C. Labels. Annals of the Natural History Museum Vienna 126 2025, 65–70 anhmw.pensoft.net 69 Hydrometra wileyi Hungerford, 1923 Hydrometra wileyi Hungerford, 1923: 57. Type locality: U.S.A., Texas, Colorado County, ca. 29°32'N, 96°28'W; holotype in SEMC. Type material. Paratypes (4 macropterous males, #11263–11265, 11268 (head missing); 2 brachypterous males, #11266, 11267; 3 macropterous females, #11269, 11270, 11274; 3 brachypterous females, #11271–11273): “Colorado Co., Tex.\ July 22, 1922,\ Mrs. Grace Wiley.”. Note. J. Polhemus (1992) proposed an unjustified emendation, Hydrometra wileyae, that is not accepted following the rules of ICZN. Hydrometra zeteki Drake, 1952 Hydrometra zeteki Drake, 1952: 2. Type locality: Panama, Canal Zone; holotype in USNM. Type material. Paratype (1 macropterous male, #11275): “Canal Zone\ Pan. 2–10–39\ C. J. Drake”. Excluded from type material Hydrometra greeni var. suensoni Hungerford & Evans, 1934 Hydrometra greeni var. suensoni Hungerford & Evans, 1934: 77 (pl. VIII), 110. Non-type material (labelled as paratypes). 2 macropterous females (#32218, 32219): “Soochow, China\ April 29, 1923\ E. Suenson”. Notes. The name “greeni var. suensoni” appears twice in the paper of Hungerford and Evans (1934): on plate VIII and in the corresponding legend in quotation marks. However, it is clear that Hungerford and Evans (1934) originally Figure 4. Hydrometra maidli, holotype, male (#11389). A. habitus, dorsal view; B. Abdominal segments; lateral view; C. Labels. anhmw.pensoft.net Herbert Zettel & Harald Bruckner: Catalogue of the Hydrometridae types in the Natural History Museum Vienna70 proposed the name “greeni var. suensoni” but eventually considered these specimens to be Hydrometra albolineata (Scott, 1874) and finally did not intend to propose this variation name, as shown in page 110 of their paper. Acknowledgements The authors are grateful to all persons who enriched the Hydrometridae collection of NHMW by donations or exchange of type specimens: Michael Balke, Carl J. Drake, Herbert B. Hungerford, Robert W. Sites, and Yang Chang Man. We cordially thank Robert W. Sites for his notes on the type locality of H. akekawati and Valerie Lemaître (The Natural History Museum, London) for help in finding out the correct publication date of the 4th issue of volume 64 of the Journal of the Kansas Entomological Society. We are thankful to Alice Laciny (NHMW) for language corrections and to Tran Anh Duc for reviewing the manuscript. 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