Gynacantha amphora Marinov & Theischinger, 2012

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 : 176-177

Gynacantha amphora Marinov & Theischinger, 2012

( Figs 5 , 14 , 23 , 29, 33b, 36g, 36f)

Gynacantha amphora Marinov & Theischinger, 2012: 6 .

Holotype ♂: Solomon Islands, Guadalcanal, 26 April 2012, forest track above Kongulae Village on the way to Kovi River , 9.45240°S, 159.90640°E; 126 m a.s.l ( RMNH); seen.

Distribution. Hitherto known only from Banika Island and Guadalcanal Island, Solomon Islands.

Material studied. Solomon Islands. Kolombangara, Iriri , 100–250 m: 1 ♀, 1 July 1964, J. & M. Sedlacek leg. ( RMNH) ; Banika Island, Russell Gp : 1 ♂, 1 ♀, 29 October C.L. Gibson, C.L. Gibson leg. 1956 (SI) ; Guadalcanal Island : 1 ♀, 28 November 1969, R. Straatman leg. ( RMNH) ; Honiara: 1 ♀, 9 December 1974, Howard R. Wimmer leg. (SI) ; 1 ♀, in huis, 200 ft, 5 November 1967, 1 ♀, in huis, 200 ft, 16 November 1967, 1 ♀, in huis, 200 ft, 25 No- vember 1967, all R. Slooff leg. ( RMNH) ; Roroni vil1age: 1 ♂, 10 May 1964 ( RMNH) ; Lower Balesuma River, Old Gravel Pit, Tetere area : 1 ♀, 25 December 1943 (SI) ; Tetere area, Balesuma Water Point , on weeds away from bank, jungle: 1 ♀, 19 December 1943, Virgil R. Knapp leg., Montgomery Purdue Collection (SI) ; Upper Cawaga Creek : 1 ♀, 21 October 1943, Virgil R. Knapp leg. (SI) ; Longa River (mouth): 1 ♂, 18 September 1944, H.E. Milliron leg. ( RMNH) ; 1 ♂, no further locality given, 12 April 20, J.A. Kusche leg., ex Bishop [the date seems to suggest that it is from 1920 but the printed labels make that unlikely but I cannot read anything else in it than “20”( RMNH)] ; Tenagli , 320 m: 1 ♂, 20 September 1965, I.R. Sloof leg. ( RMNH) ; no other locality given: 1 ♂, C.H. Foggitt, E.C. van Dyke leg., ex coll. Calif. Ac. Sci. 1948 ( RMNH) ; Valevahalo base camp, 9.6468°S / 160.0447°E, 810 m a.s.l.: 1 ♀, 11 September 2015, M. Marinov leg. ( NZAC) .

Female. The description of the supposed female by Marinov (2016) is validated in this paper. The most useful diagnostic character of female G. amphora is the larger number of cells between the membranule and the primary anal lobe along vein A in the hindwing which is five, rarely six, cells vs generally four cells in all other species of the Gynacantha rosenbergi group of species.

Distribution: Solomon Islands: known from Guadalcanal and Banika.

Diagnostic characters: Postfrons with very thick-stemmed dark T-mark. Both Hw with space between CuP and A1 basally not expanded and generally without double cells in proximal half. The few (3–8) small denticles along posterior portion of genital fossa not regularly arranged or densely set, no denticles in anterior part. Superior anal appendages very slender, straight to very slightly sinuous, clubbed with subapical part not wider than 1.5 times basal width and with apex narrowly produced postero-laterally into a short, not particularly acute point; inferior appendage less than 1/3 the length of superiors, with lateral edges of basal portion convex and rather abruptly narrowing into an only slightly tapered narrow apical part.

Distinguished from G. rosenbergi and the non-overlapping G. dobsoni by (1) having three, rarely four, rows of cells between anal triangle and anal loop, (2) a pale mid-dorsal pattern element in S2, (3) by the much more strongly swollen posterior part of S3 and (4) by fewer (3–8) and very small denticles along genital fossa that are restricted to the posterior part.

Figures

FIGURE 23. Gynacantha amphora, male, insert: S2, ventral; anal appendages, dorsal; part of Hw.

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.