Nososticta acuminata, Michalski, John, Richards, Stephen & Theischinger, Gunther, 2012

Michalski, John, Richards, Stephen & Theischinger, Gunther, 2012, An interesting new species of Nososticta Hagen from southern New Guinea (Odonata, Disparoneuridae), Zootaxa 3590, pp. 73-78 : 73-77

Nososticta acuminata sp. nov.

( Figs 1–11 , 15, 16 )

Material. Holotype 3 ( NTM I008853): Papua New Guinea, Gulf Province, Lakekamu, 1 km transect near Ivimka Camp (146o29’45”E, 7o44’05”S, approx 120 m asl), 1 Dec. 1996, S.J. Richards ( NTM). Paratypes: 1 3 ( NTM I008854), 22 Nov. 1996; 2 3 ( NTM I008855–6), 26 Nov. 1996; 1 3 ( NTM 1008857), Nov.1996; all within 1 km south of Ivimka Camp by S.J. Richards.

Other material ( RMNH, presently lost): Papua New Guinea, Gulf Province, Lakekamu Basin: 1 3, forest trail 500 m south of Ivimka Camp (146o29’45”E, 7o44’05”S, approx 120 m asl), 18 Nov. 1996;1 ♀, along forest trail 1 km S. Ivimka Camp, Lakekamu; 24 Nov. 1996; both S.J. Richards.

Etymology. The species is named for its distinctively pointed cerci ( acuminata = Latin for sharp).

Male. Labium black, paler at base; rear of head black. Entire dorsal surface of head, including labrum, dull black. Frons with a pale blue transverse fascia, running from eye to eye but not occupying the clypeus lower down; this stripe unbroken in the middle. An indistinct, vaguely defined dark reddish spot between each lateral ocellus and the base of the antenna.

Pronotum black, unmodified; propleura black adjacent to pronotum, otherwise pale.

Synthorax marked as in Fig. 1 . Synthorax entirely semi-gloss black, down to interpleural suture and including upper three-fourths of mesinfraepisternum. Synthorax posterior to interpleural suture pale blue dorsally, fading to beige ventrally. Metapleural suture covered by broad black stripe, which reaches from its dorsal end to level of metathoracic spiracle, or a little beyond. Metinfraepisternum mostly dirty greyish. Venter pale and unmarked.

First coxa somewhat pale. First and second femora black, third femora basally dark brown, grading to black in distal one third. All tibiae very dark brown, almost black.

Wings lightly tinted greenish-yellow. CuP extends beyond quadrilateral to only about one-fourth of way to next crossvein before meeting posterior margin of wing. No transverse crossvein descending from distal margin of quadrilateral to wing margin. Pterostigma black, oblique, slightly widened distally, covering a little less to a little more than one cell in both wings. Ac very slightly proximal to slightly distal to Ax 1. 15–17 postnodals in forewing, 13–15 in hindwing.

Abdomen glossy black, segments 1–2 paler below. Apical ring on segment 9 and all of segment 10 yellowish brown to red dorsally, darker to blackish on sides. Anal appendages entirely yellowish brown to reddish, shaped as in Figs 3–5 .

Measurements: abdomen + appendages 31.5–33.3 mm; hindwing 18.0– 19.6 mm.

Diagnosis. A predominantly black damselfly with a pale (blue in life?) stripe across the frons, lateral thoracic stripes of the same color, and red terminalia. Male cerci ending in an acute tooth or spike.

Female. Agrees with male in all details of body marking and coloration, wing venation, and even the color of the terminalia.

Hind lobe of pronotum developed into a pair of long, flattened, forward-arching horns—poorly preserved in the sole example (Figs 6,7). Thorax marked as in Fig.2 . Terminalia as in Fig. 8. 15 postnodals in forewing, 13 in hindwing. Pterostigma covers slightly more than one cell in both wings.

Female abdomen + appendages 30 mm; hindwing 19 mm.

Figures

FIGURES 1 – 8. Nososticta acuminata sp. nov.: 1, 2 thoracic markings: 1 male; 2 female; 3 – 5 male terminalia: 3 lateral; 4 dorsal; 5 right superior appendage, dorso-interior view; 6,7 female prothorax: 6 lateral; 7 posterior lobe of pronotum, dorsal; 8 female terminalia, lateral.

FIGURES 9 – 14. Male terminalia of Nososticta species: 9 – 11 Nososticta acuminata sp. n.: 9 dorsal; 10 superior appendage, outline; 11 lateral; 12 – 14 Nososticta smilodon Theischinger & Richards: 12 dorsal; 13 superior appendage, outline; 14 lateral.

FIGURES 15, 16. Nososticta acuminata sp. nov.: 15 male; 16 female.