Oesyperus unctulus Andrewes, 1923

Kataev, Boris M., 2006, A taxonomic review of the genus Oesyperus (Coleoptera: Carabidae: Harpalini), Zootaxa 1286, pp. 43-55 : 47-49

Oesyperus unctulus Andrewes, 1923

( Figs 1 , 6–8 )

Oesyperus unctulus Andrewes, 1923: 445 . Type locality: "Madras: Palni Hills, Kodaikanal, 6900–7200 feet ”, India.

Merklia pubens Ito, 2004: 109 , syn. n. Type locality: Palni Hills, Berijam Nature Park, Tamil Nadu, 2100 m, India.

Type material. Holotype of Oe. unctulus : ɗ, labelled "Kodai Kanal, S. India, T.V. Campbell", " Type ", " Oesyperus unctulus Andr. , Type, H.E. Andrewes det.", "H.E. Andrewes Coll., Brit. Mus. 1945–97." ( NHML).

Redescription (based on the holotype). Size: Length 8.6 mm, width 3.7 mm.

Habitus: Fig. 1 .

Colour: Body dark, poorly shiny on dorsum: head and pronotum nearly black, elytra slightly paler, dark brown; labrum, base of mandibles and very narrow lateral margins of pronotum reddish brown. Palpi, antennae and legs pale, light brownish yellow.

Head: Medium sized (WHmax/WPmax = 0.67; WHmin/WPmax = 0.57), with comparatively small and weakly convex eyes separated from buccal fissure ventrally by distance approximately equal to length of second antennomere. Temples long, rather flat, sloping to neck constriction. Frontal suture shallow, clypeo­ocular prolongations slightly deepened throughout. Supraorbital furrows straight, moderately prolonged to neck constriction behind eyes and not curved ventrad distally. Labrum concave apically. Penultimate labial palpomere longer than apical one ( Fig. 6 ). Puncturation of dorsal surface of head coarse, sparse and irregular (distance between punctures usually greater than their diameter). Dorsal microsculpture distinct throughout, consisting of isodiametric meshes.

Pronotum: Rather flat, moderately transverse, 1.39 times as wide as long, cordate, widest before middle (WPmax/WPmin = 1.30). Apical margin arcuately, moderately emarginate. Apical angles slightly protruding, narrowly rounded at apices. Basal margin approximately equal to apical margin and slightly narrower than base of elytra between humeral angles, more or less straight medially, slightly oblique laterally. Sides clearly sinuate in basal third, very finely bordered. Basal angles slightly obtuse and slightly blunt at apex. Lateral margins and latero­basal areas slightly flattened, weakly explanate at basal angles. Basal foveae very wide, indistinct. Dorsal puncturation irregular, rather coarse and sparse, distributed almost throughout (sparser in central portion). Dorsal microsculpture distinct throughout, consisting largely of transverse meshes (more or less isodiametric at basal margin).

Elytra: Oval, moderately long, 1.42 times as long as wide, 2.50 times as long and 1.27 times as wide as pronotum, somewhat flat basally and rather convex apically, base of each elytron with depression between scutellum and humeral angle. Preapical sinuation moderate. Sutural angle acute, narrowly rounded at apex. Basal edge rather strongly sinuate laterally, forming with lateral margin a very obtuse angle with rounded apex. Striae impunctate, deepened throughout, slightly widened posteriad. Parascutellar striole rather short, with large basal pore. Intervals convex, strongly narrowed to apex. All intervals somewhat coarsely punctate, usually with two punctures in transverse row on each interval on disc. Third interval with 5(6) discal pores usually not connected with second stria. Microsculpture visible throughout, meshes weakly transverse on disc, more or less isodiametric basally and apically.

Legs: Protibia with two preapical spines on outer margin. Metafemur with three longer and several shorter setae along posterior margin. Metatarsus approximately as long as WHmax, with first tarsomere as long as second and third together.

Male genitalia: Median lobe of aedeagus ( Figs 7–8 ) moderately arcuate, with almost straight ventral margin of medial portion (lateral aspect). Terminal lamella rather short and wide, evenly narrowed to rounded apex (dorsal aspect) and clearly, but not strongly, bent dorsad at tip.

Distribution. Known only from Palni Hills in southern India.

Remarks. Oesyperus unctulus was described from two localities (“ 6900–7200 feet and … 6850 feet ”) in Kodaikanal, Palni Hills, India. This species is easily distinguished from the other two species of the genus by the cordate pronotum with clearly sinuate sides. Merklia [= Merklophonus] pubens was described on the basis of five specimens (four males and one female) collected together in the same area (Palni Hills) without reference to Oe. unctulus . The original description fully agrees with the holotype of Oe. unctulus and I believe that the two taxa are identical.

Figures

FIGURES 1 – 3. Oesyperus, habitus. 1, Oe. unctulus; 2, Oe. planus; 3, Oe. pygmaeus. Scales = 25.0 mm (A: 1, 2; B: 3).

FIGURES 6 – 8. Oesyperus unctulus. 6, labium; 7, median lobe, lateral aspect; 8 – same, dorsal aspect. Scales = 0.5 mm (A: 6, B: 7 – 8).