Gynacantha stevensoni Fraser, 1927

Theischinger, Gunther, Marinov, Milen, Bybee, Seth, Jensen, Colin, Theuerkauf, Jörn & Rashni, Bindiya, 2020, The genus Gynacantha Rambur, 1842 in the South Pacific (Odonata: Anisoptera: Aeshnidae), Zootaxa 4778 (1), pp. 171-195 : 186-187

Gynacantha stevensoni Fraser, 1927

( Figs 9 , 19 , 31 )

Gynacantha stevensoni Fraser, 1927: 36 .

Holotype: ♂ ( BMNH), Kingdom of Tonga, Nuku’alofa ; detail photos studied.

Distribution. Only known from Tonga.

Diagnostic characters: Postfrons with dark T-mark. Both Hw with space between CuP and A1 basally not expanded but with a few double cells in one wing. Denticles along posterior portion of genital fossa rather widely spread, the odd denticle or two present along anterior part. Superior anal appendages slightly converging, at least their apical half widely and evenly curved and with apex rather narrowly curved postero-laterally into a short point; inferior appendage with lateral edges of basal portion convex and rather abruptly narrowing into slightly tapered apical portion.

Only species of Gynacantha known from Tonga. Distinguished from G. apiaensis by pointed, less sinuous superior anal appendages, and from G. vanuatua , G. vitiana and G. koroana by more in-curved (converging) superior anal appendages.

Figures

FIGURE 31. Gynacantha stevensoni, male, Holotype; insert: S2, ventral; anal appendages, dorsal.

FIGURES 3–11. Gynacantha species, male S2, ventral (to show arrangement of denticles along genital fossa): (3) G. rosenbergi; (4) G. dobsoni; (5) G. amphora; (6) G. vanuatua; (7) G. vitiana; (8) G. koroana; (9) G. stevensoni; (10) Gynacantha cf stevensoni; (11) G. apiaensis.

FIGURES 12–21. Gynacantha species, male anal appendages dorsal (to show differences between width of S10 and length of superior anal appendages): (12) G. rosenbergi; (13) G. dobsoni; (14) G. amphora; (15, 16) G. vanuatua; (17) G. vitiana; (18) G. koroana; (19) G. stevensoni; (20) G. cf stevensoni; (21) G. apiaensis.