The genus Ophiogomphus Lieftinck, 1964 in Vietnam, with descriptions of the female of O. minimus Karube, 2014 and O. phantoani sp. nov. (Odonata: Gomphidae) Author Ngo, Quoc Phu Center for Entomology & Parasitology Research, College of Medicine & Pharmacy, Duy Tan University, Da Nang 550000, Vietnam. Institue of Applied Technology, Thu Dau Mot University, No. 06 Tran Van On, Phu Hoa Ward, Thu Dau Mot City, Binh Duong province, Vietnam. https: // orcid. org / 0000 - 0002 - 2023 - 1813 Author Nguyen, Minh Ty 0000-0002-2023-1813 text Zootaxa 2021 2021-11-03 5061 1 134 144 journal article 3612 10.11646/zootaxa.5061.1.6 0e4f0459-0892-43b2-b01d-50f384c6c945 1175-5326 5679421 AED1C537-0DEF-4356-BDE9-E590A9EBCDD3 Ophiogomphus (Ophionurus) minimus Karube, 2014 ( Figs 1–3 , 16, 18 , 22, 23 , 30, 31 ) Examined specimens . 5 ♂♂ , 1 ♀ , Aso Commune ( 15.8268 N , 107.6792 E , altitude 528 m ), Dong Giang District , Quang Nam Province , Vietnam , 12.v.2014 , V . T . Nguyen leg. ; 12 ♂♂ , 6 ♀♀ , Nam Nung Nature Reserve ( 12.2545 N , 107.7926 E , altitude 819 m ), Dak Nong Province , Vietnam , 12.v.2020 , Q.P. Ngo & Q. T . Phan leg. ; 3 ♂♂ , Song Thanh National Park ( 15.2566 N , 107.7378 E , altitude 775 m ), Phuoc My Commune , Phuoc Son District , Quang Nam Province , Vietnam , 19.v.2020 , Q.P. Ngo leg. ; 2 ♂♂ , K Stream ( 11.8716 N , 107.9824 E , altitude 598 m ), Ta Dung National Park , Dak Nong Province , Vietnam , 28.vi.2020 , Q.P. Ngo leg. ; 1 ♂ , 1 ♀ , Khe Voi , Son Kim 1 Commune ( 18.4018 N , 105.2846 E , altitude 125 m ), Huong Son District , Ha Tinh Province , Vietnam , 24.vii.2020 , Q.P. Ngo & Q. T . Phan leg. ; 3 ♂♂ , Khe Da Lai ( 18.1762 N , 105.5371 E , altitude 160 m ), Phu Gia Commune , Huong Khe District , Ha Tinh Province , Vietnam , 19.vii.2020 , Q.P. Ngo & Q. T . Phan leg. ; 3 ♂♂ , Hoa Trung ( 16.0950 N , 108.0491 E , altitude 191 m ), Hoa Lien Commune , Hoa Vang District , Danang City , Vietnam , 19.v.2021 , Q. T . Phan leg. Notes. This species was described from Bao Loc, Lam Dong Province , southern Vietnam , based on a male specimen ( Karube 2014 ). The female is described based on the specimen from Nam Nung Nature Reserve, Dak Nong Province . FIGURES 1–3 . Ophiogomphus minimus , ♀. (1), habitus, lateral view; (2), head, frontal view; (3), head, dorsal view. Scale bar is 1 cm. Description of female Head . Labium greenish yellow; labrum black with a pair of yellow stripes laterally; anteclypeus greenish yellow; postclypeus black with small yellow patch each at dorso-lateral corner; frons largely greenish yellow, black medially; antennae black, ventral margin of the second segments yellowish; vertex entirely black with rounded prominence above lateral ocelli ( Figs 2–3 ). Occiput with two erect horns dorsally ( Figs 16 , 30 ). Thorax ( Fig. 1 ). Prothorax mostly black with a tiny greenish yellow spot on middle pronotal lobe. Synthorax robust, black with yellow markings; black antehumeral and humeral stripe connected, leaving only a small spot ventrally; dorsal carina yellow; interpleural stripe broad encompassing posterior half and anterior halves of mesepimeron and metepisternum respectively, this stripe interrupted medially by narrow patches of yellow; metepimeron largely yellow except for anterior and ventral margin. Wings ( Fig. 1 ). Wings hyaline with black venation except the base tinged with yellow; anal loop 2-celled; nodal index: Ax/Px = 17/21 (FW) and 14/23 (HW). Pt black, 4.5–5 mm length in both wings, covering about 8 underlying cells. Abdomen ( Fig. 1 ). Black with greenish yellow markings as follows: S1 with a lateral large spot; S2 greenish yellow markings on anterior and posterior margin and part of posteroventral margin black; S3 with a large spot on anterior margin; S4–6 mostly black with a narrow basal rings; anterior half S7 yellowish; S8–10 entirely black. Anal appendages ( Figs 18 , 31 ) Cerci yellowish brown, conical, longer than S10. Epiproct broad, shorter than S10. Vulvar lamina on S9, incised apically. Measurements [mm]. Abdomen (including appendages) 39, HW 32. Morphological variation in females. The variation of measements of body varies as follows: Measurements: abdomen (including appendages) 38–40, HW 32–35 mm . The basal area of wings of two specimens from Nam Nung Nature Reserve is paler than those from other localities. Distribution ( Fig. 36 ). Vietnam : Ha Tinh , Thua Thien Hue, Quang Nam , Da Nang , Kon Tum , Dak Nong and Lam Dong Provinces ( Karube 2014 ; Karube et al. 2020 ; this study).