Polyrhachis (Hemioptica) becvari, Zettel & Ockermüller & L, 2023

Zettel, Herbert, Ockermüller, Esther & L, Sri, 2023, Polyrhachis (Hemioptica) becvari nov. sp. (Hymenoptera, Formicidae) from Sri Lanka, Linzer biologische Beiträge 55 (1), pp. 373-380 : 375-377

Polyrhachis (Hemioptica) becvari nov.sp. ( Figs 1-8 )

T y p e m a t e r i a l. Holotype (worker): Sri Lanka, Southern Province, Matara District, 3 km NW of Kotapola [labelled "Kotopola"], 4-8.XII.1995, leg. S. Bečvář, deposited in Biologiezentrum Linz, Upper Austria. Paratypes: 12 workers, 1 dealate gyne, same locality data. Holotype and paratypes in Biologiezentrum Linz, further paratypes in collection of first author. Labels see Figs 3, 4.

D i a g n o s i s o f w o r k e r: Small,blackspecieswithdense,attached pilosity and relatively long standing setae on dorsum of head, mesosoma, and gaster. Eyes hardly truncated. Head with sharp lateral margin. Mesosoma stout, not marginate. Pronotum and mesonotum fused, convex, anteriorly with blunt angle. Metanotal suture separating mesonotum from propodeum narrow and deep. Propodeum toothless, with convex dorsum and slightly concave posterior face, both completely separated by a sharp ridge. Petiole stout, laterally with small sharp teeth, ridge between them convex, without mediodorsal emargination.

D e s c r i p t i o n o f w o r k e r: Measurementsofholotype.TLca.5.7;HW 1.28; HL 1.45; EL 0.41; SL 1.72; MSL 1.79; PNW 1.27; PML 0.86; PPW 0.99; MTL 1.11; PEL 0.59; PEW 0.95; GL 1.76; GW 1.68. Indices: CI 89; EI 32; SI 134.

Measurements of paratypes (n = 11). TL ca. 5.4-6.3; HW 1.19-1.35; HL 1.36-1.54; EL 0.35-0.41; SL 1.58-1.94; MSL 1.68-1.93; PNW 1.13-1.31; PEW 0.89-1.02; GL 1.80-2.08; CI 86-90; EI 29-31; SI 128-145.

Structures. Head ( Fig. 1 ), mesosoma, petiole, and gaster chiefly with dense reticulation, moderately shiny. Head longer than wide; occiput strongly convex in frontal view. Frontal carina strongly raised above antennal fossa; frontal area between carinae narrower than dorsally, finely punctured. Occipital carina slightly concave behind eye, so that underside of head narrowly visible in a strict lateral view. Eye moderately large, hardly truncated and protruding; hind margin straight. Clypeus finely punctured, with some larger punctures at bases of setae, without median carina; anterior margin with a minute, hardly visibly medial emargination. Frontal triangle not delimited. Ocelli lacking. Mandibles with scattered, fine punctures. Antennal scape slender, steadily widened towards apex, over most of its length more slender than flagellum; base of scape, distal of condyle, strongly curved.

Mesosoma ( Figs 5, 6 ) without lateral margins; in lateral view both the fused promesonotum and the propodeum with convex outlines; with a deep fissure between these two parts. In dorsal aspect, pronotal corners forming a blunt angle or almost rectangular; collar distinct. Promesonotal suture not recognizable. Metanotal suture very deep, its ground smooth and shiny; suture posteriorly pronounced by the sharp anterio-dorsal edge of propodeum. Propodeum without spines, with a complete carina separating the concave posterior face.

Petiole stout in lateral aspect ( Fig. 5 ); dorsal crest evenly convex, terminated laterally by small acute teeth. Gaster slightly longer than wide.

Pilosity. Entire body bearing a thin, pale grey pilosity, not completely covering integument. Pale standing setae on dorsum of head, mesosoma, and gaster, and on gastral sterna relatively long and abundant; lacking on body sides, scape and legs, except a few standing pale setae on coxae, trochanters, and flexor sides of femora (on metafemur only at base). Mandible with scattered setae, distally longer than elsewhere.

Colour. Black. Palpi yellow. Tibiae dark red, except base and extreme apex black.

D e s c r i p t i o n o f g y n e: Measurementsofparatype.TLca.7.1;HW1.49; HL 1.64; EL 0.49; SL 1.94; MSL 2.57; PNW 1.44; PNL 0.50; PPW 1.17; MTL 1.29; PEL 0.54; PEW 1.07; GL 2.21; GW 2.10. Indices: CI 91; EI 33; SI 130.

Structures. Similar to worker. Head ( Fig. 2 ): Eyes slightly larger and more prominent than in worker. Ocelli present. Medial incision of clypeus small, but more distinct than in worker. Pronotal humeri blunter than in worker. Structures of mesosoma as typical for gynes. Metanotum lower than mesoscutum; metanotal suture deep and distinct ( Fig. 7 ). Wings broken off.

Pilosity and colour similar as in worker.

C o m p a r a t i v e n o t e s: DOROW & KOHOUT (1995) constructed a key to the species of Hemioptica . Therein, P. bugnioni is characterised by small size, silverish pubescence of body, and hardly truncated eyes. The new species is similar to P. bugnioni in these characters, but there are several differences: The frontal carinae are highly elevated in P. becvari nov.sp., but relatively low in P. bugnioni . The setae on the occiput of head and on pronotum are long (distinctly longer than scape width) in P. becvari nov.sp., but short in P. bugnioni . Femora are black in P. becvari nov.sp., but red in P. bugnioni .

The petiole of the new species is wider, and its summit is lacking a small emargination as described for P. bugnioni by FOREL (1908: "faiblement échancré au sommet").

D i s t r i b u t i o n: Sri Lanka, Southern Province, only known from types.

E t y m o l o g y: Named to honour the collector of the new species, the Czech coleopterist Stanislav Bečvář.

Figures

Figs 1-4: Polyrhachis (Hemioptica) becvari nov.sp., heads in frontal view: (1) holotype, worker; (2) paratype, gyne. (3) Labels of holotype. (4) Labels of paratype © E. Ockermüller.

Figs 5-6: Polyrhachis (Hemioptica) becvari nov.sp., holotype, worker; (5) lateral view; (6) dorsal view. © E. Ockermüller.

Figs 7-8: Polyrhachis (Hemioptica) becvari nov.sp., paratype, gyne; (7) lateral view; (8) dorsal view. © E. Ockermüller.