Ranatra heoki Tran & Poggi, 2019

Tran, A. D. & Zettel, H., 2021, Taxonomic review of the Ranatra gracilis group sensu Lansbury, 1972 (Nepomorpha: Nepidae), with descriptions of four new species, Raffles Bulletin of Zoology 69, pp. 45-70 : 66-67

Ranatra heoki Tran & Poggi, 2019

Ranatra heoki Tran & Poggi, 2019: 241–244 (type locality: Sarawak, Borneo ).

Additional material examined. BRUNEI: 4 males, 1 female ( ZRC.6.18837, NHMW), Tutong District, Logon Uluh Boyoh (pool) and Bawang Ulop (stream), coll. Tan H.H., 17 May 1996, THH9633 . INDONESIA: Bintan: 1 male ( ZRC), Pulau Bintan North, swamp forest at Tanjung Bintan end, east of Pasir Panjang beach, ca. 100–200 m from sea, coll. H.H. Tan, 27 June 1995, THH9529 .

Diagnosis. Body length: males 25–26, female 29; ratio of siphon length: body length ca. 0.55; siphon index ca. 1.55×; lorum lower clypeus and without nodule dorsally; clypeus with a small conical tubercle anteriorly; ratio of eye width: interocular width ca. 1.0; posterior width of pronotum ca. 1.15× anterior width; pronotal length ca. 1.55× fore coxa length; hemelytra reaching mid-length of abdominal tergum VI; posterior margin of metasternum angularly emarginated, with sublateral grooves; fore femur on flexor side with a median tooth and a median carina, and with one small preapical tooth; hind femur of male, when folded back parallel to body just surpassing mid-length of abdominal sternum VI; in female slightly shorter; paramere: ventral side before apical hook with a small sub-triangular process, apical hook relatively short, tip of hook pointed.

Description of female. Colouration similar to males.

Body length 29; length of siphon 14.2; width of head 2.47; interocular width 0.76; width of eye 0.83; pronotal length 7.36, anterior pronotal length 5.80; posterior pronotal length 2.85; anterior width of pronotum 2.05; posterior width of pronotum 2.63; lengths of leg segments: fore leg: coxa 4.55, femur 7.82, tibia 3.17, tarsi 0.68; middle leg: femur 10.90, tibia 9.75, tarsi 1.80; hind leg: femur 11.75, tibia 13.65, tarsi 1.96. Hind femur, when folded back parallel to body, just not reaching middle of abdominal sternum VI. Operculum slightly longer than connexivum, surpassing the apex of connexivum by about one-tenth the length of operculum. Respiratory siphon about 1.4× the length of sterna III–V combined.

Other characteristics similar to males.

Distribution. Borneo: Malaysia: Sarawak ( Tran & Poggi, 2019), Brunei (first record). Indonesia: Pulau Bintan (first record).