Ophiogomphus (Ophionurus) minimus Karube, 2014

Ngo, Quoc Phu & Nguyen, Minh Ty, 2021, The genus Ophiogomphus Lieftinck, 1964 in Vietnam, with descriptions of the female of O. minimus Karube, 2014 and O. phantoani sp. nov. (Odonata: Gomphidae), Zootaxa 5061 (1), pp. 134-144 : 135-136

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.

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).

Figures

FIGURE 36. Distribution map of four Ophiogomphus spp. in Vietnam. O. longihamulus (red circle); O. minimus (purple circle); O. phantoani sp. nov. (yellow circle); O. sinicus (green circle). Map background source © GoogleTM Earth Service version 7.3.3.7786.

FIGURES 1–3. Ophiogomphus minimus, ♀. (1), habitus, lateral view; (2), head, frontal view; (3), head, dorsal view. Scale bar is 1 cm.

FIGURES 16–19. Posterior head and vulva lamina of Ophiogomphus spp., ♀. (16, 18), O. minimus & (17, 19), O. phantoani sp. nov.

FIGURES 20–27. Accessory genitalia [20, 22, 24, 26] in lateral view and cornua of glans [21, 23, 25, 27] in ventral view of Ophiogomphus spp. (20–21), O. longihamulus (rearranged from Karube 2014: Fig. 16 e, g); (22, 23), O. minimus (rearranged from Karube 2014: Fig. 18 e, g); (24, 25), O. phantoani sp. nov.; (26, 27), O. sinicus, Cao Bang Province.

FIGURES 28–35. Female occiput [28, 30, 32, 34] & abdominal end [29, 31, 33, 35] in ventral view of Ophiogomphus spp. (28, 29), O. longihamulus (rearranged from Karube 2014: Fig. 16 j, k); (30, 31), O. minimus, Nam Nung Nature Reserve; (32, 33), O. phantoani sp. nov.; (34, 35), O. sinicus (rearranged from Chao 1990: Fig. 10 & Zhang 2019: p. 424).