Nososticta impercepta, Seehausen, Malte & Theischinger, Günther, 2017

Seehausen, Malte & Theischinger, Günther, 2017, Nososticta impercepta sp. nov. (Odonata: Platycnemididae) from Timor, with a key to the Sundaic species, Zootaxa 4250 (3), pp. 262-274 : 263-267

Nososticta impercepta sp. nov.

Figures: 1 (locality map); 2 (holotype male lateral); 3 (paratype female); 4 (wing base); 5q (male synthorax); 5r (male abdomen S8–10 dorsal & lateral); 5s (male anal appendages lateral); 5t (male ligula); 6q (female synthorax); 6r (female abdomen S8–10 dorsal & lateral); 6s (female prothorax lateral); 6t (female prothorax dorsal).

Holotype: ♂, 28.vi.1911, Niki-Niki [South Central Timor Regency], Timor, Indonesia, C.B. Haniel leg., Coll. Ris, No. 2477. Deposited at the Forschungsinstitut und Naturmuseum Senckenberg , Frankfurt am Main, Germany ( SMF) .

Paratypes (5♂ 3♀): 2♂, xii.1931 – i.1932, Amarassi [Amarasi, SW Timor], Timor, Indonesia, E. Handschin leg. ( RMNH) . 2♀, xii.1931 – i.1932, Koepang [Kupang, SW Timor], Timor, Indonesia, E. Handschin leg. ( RMNH) . 2 ♂, 5.vi.2012, spring, 3.8 km WNW Manatuto, Municipality Manatuto, Timor-Leste, 8.50847° S, 125.98292° E, 130 m a.s.l. (AMS) . 1♀, iv–v.1929, Kolbano , [South Central Timor Regency], West Timor, Indonesia, ex- coll. Le Moult ( RBINS) . 1♂, 1929, Soe [South Central Timor Regency], Timor, Indonesia, Coll. Ris ( SMF, No. 30133).

Etymology. The Latin adjective ‘imperceptus’ means ‘not recognized’ or ‘undiscovered’. Named according to the mistaken assignment to Nososticta selysi in the past, whereby the species remained undiscovered.

Holotype male ( Fig. 2 ). Head: Labium, mandibles, genae, labrum and anteclypeus dark blackish brown; postclypeus orange; antefrons left and right of clypeus an orange bar towards the eyes; frons and vertex black, with washed orange-brown spots beside the lateral ocelli; rear of head black; base of antennae black, following segments brown.

Thorax: Pronotum black with two yellow-orange patches dorsolaterally on anterior and median lobe; posterior lobe black with small yellow-orange spots laterally; hind margin of posterior lobe convex; synthorax black with yellow-orange antehumeral patches covering anterior two-thirds of mesanepisternum, narrowing anteriorly and rounded posteriorly; broad yellow-orange stripe on metepisternum curving down anterior of yellow metastigma; almost quadrangular yellow-orange patch at posterior metepimeron; poststernum suture around middle of metepimeron with a thin elongate yellow-orange spot; venter of synthorax washed dark brownish black; legs ochre, outer side washed with a dark brown stripe; tip of tarsi and tarsal claws brown; spines blackish.

Wings: Membrane hyaline; veins brown to black; CuP reaching wing margin at about half a cell following discoidal cell in forewing and almost two cells following discoidal cell in hindwing (around level of nodus); Ac situated at level of Ax1; anal vein absent; 15.5 Px in forewing, 13–14 Px in hindwing; Pt dark reddish-brown, overlying one cell.

Abdomen: S1–6 dark brownish; S1 and S2 with washed pale spots laterally; S3–6 with a pair of small pale spots at anterior suture and a pale ring in posterior sixth of each segment, followed by blackish to end of segment; S7–10 blackish but S8–9 with orange-brownish marking dorsally and laterally, expanding from anterior suture and lateral carina to almost posterior end of each segment and leaving a small posterior part dorsally black; cercus washed brown, about as long as S10; cercus triangular dorsally with apex bluntly rounded, large acute tooth on inner side almost reaching to middle of paraprocts; paraprocts dark brown to black with inner margin washed pale; basal part of same length as cercus, but posterior tip expanding behind cercus, curving upward with tip bluntly pointed.

Genital ligula: Terminal segment ventrally trapezoidal with a pair of apical lobes and a pair of lateral lobes; apical lobes about half as long as lateral ones, laterally spoon-shaped; lateral lobes narrower, about as long as terminal segment, tips lunately curved; inner fold present.

Measurements (mm): Total length (with appendages) 43.0; abdomen length (without appendages) 35.6; hindwing 23.2; forewing 24.3; Pt in forewing 1.0.

Variation in paratype males

Head: As in holotype but pale color in apparently younger specimens yellow.

Thorax: As in holotype but pale color in apparently younger specimens yellow; in one male [originally stored in ethanol] it appears as if the pale markings may be magenta or scarlet.

Wings: As in holotype but 14–15.5 Px in forewing and 12.5–14.5 Px in hindwing.

Abdomen: Pale color on S 8–9 in apparently younger specimens yellow; in one male [originally stored in ethanol] it appears as if the pale markings may be magenta or scarlet; two males have a pair of small pale dorsal spots on S10.

Measurements (mm): Total length (with appendages) 39.0–42.6; abdomen length (without appendages) 32.5– 33.2; hindwing 20.0–22.0; forewing 21.3–23.1; Pt in forewing 1.0.

Description of Female ( Fig. 3 ). Head: As in male.

Thorax: Anterior lobe of pronotum yellow laterally, dark at midline; erect anterior lobe convergent, notched in middle; median lobe black with a yellow lateral band; posterior lobe yellow laterally and black in middle, bearing two long horn-like processes, about as long as 1/3–1/2 height of prothorax at level top of median lobe; synthorax as in male but with yellow antehumeral patches smaller, covering anterior two-thirds and half width of mesanepisternum; venter of synthorax washed dark brownish black as in male; legs as in male.

Wings: As in male but Pt pale brown.

Abdomen: As in male but S8 with two semicircular to almost triangular spots anteriorly and a transverse stripe posteriorly; S9 with a broad transverse stripe posteriorly, bulged in middle; S10 black; appendages yellow-ochre; ovipositor reaching beyond end of S10; two styli caudally; outer valves bearing around 30 sharp teeth.

Measurements (mm). Total length (with appendages) 41.0–44.0; abdomen length (including appendages) 33.5–37.0; hindwing 22.0–24.0; forewing 23.5–25.0; Pt in forewing 1.0.

Diagnosis. Nososticta impercepta has the vein CuP in hindwing long, reaching one or more entire cells past the discoidal cell ( Fig. 4 ). This character distinguishes all Sundaic species from all Papuan and Australian species (CuP shorter, commonly reaching less than one entire cell past the discoidal cell). The Sundaic species N. diadesma , N. emphyla , N. insignis and N. selysi differ from N. impercepta by the color pattern of the synthorax and S8–9 of the abdomen, the shape of the male anal appendages, and the morphology of the female pronotum. The genital ligula separates three groups: Nososticta insignis has long apical lobes and lateral lobes of about the same length ( Fig. 5 l), N. diadesma and N. emphyla have short apical lobes and lateral lobes only slightly longer ( Figs 5 d & h), N. selysi and N. impercepta have short apical lobes but long lateral lobes ( Figs 5 p & f).

For differential diagnosis see the key to species.

Figures

FIGURE 2. Holotype male of Nososticta impercepta with labelled envelope (deposited at Coll. Ris, SMF). Photos: Malte Seehausen.

FIGURE 3. Paratype female of Nososticta impercepta with label (deposited at RBINS). Photos: Malte Seehausen.

FIGURE 4. Nososticta impercepta wing base. Illustration: Malte Seehausen.

FIGURE 5. Nososticta males (synthorax, S 8 – 10 of the abdomen dorsal and lateral, appendages lateral, ligulae lateral); (a – d) Nososticta diadesma; (e – h) Nososticta emphyla; (i – l) Nososticta insignis; (m – p) Nososticta selysi; (q – t) Nososticta impercepta. Illustrations: Malte Seehausen.