Parosus bicoloratus, Makranczy & H-, 2014

Makranczy, György, 2014, Review of the genus Parosus Sharp, 1887 (Coleoptera: Staphylinidae, Oxytelinae), Revue suisse de Zoologie 121 (1), pp. 77-133 : 88-92

Parosus bicoloratus sp. nov. Figs 25, 41, 44, 56-59

TYPE MATERIAL: HOLOTYPE (3), “ ECUADOR: Pichincha [Prov.], Nanegalito, 12km S, Bellavista Nature Reserve ca. 2200m, 0°0'54"S, 78°40'56"W, 28 Oct 1999; [leg.] Z. H. Falin ( ECU1 F99 035), pyrethrum fogging fungusy log” ( SEMC). – PARATYPE (1): ECUADOR: Pichincha Prov., old Quito-Santo Domingo road, W Chiriboga [0°16'21"S, 78°43'26"W], 6500-7000’, 13.VI.1982, leg. H. Frania, dead vegetation in trees ( CNCI, 1) .

DESCRIPTION: Forebody and abdomen as in Fig. 44. Measurements (n=2): HW = 0.81 (0.75-0.86); TW = 0.81 (0.76-0.86); PW = 0.77 (0.73-0.80); SW = 0.73 (0.70-0.76); MW = 0.86 (0.82-0.90); AW = 0.72 (0.68-0.76); HL = 0.64 (0.60-0.68); EL = 0.15 (0.14-0.15); FL = 0.12 (0.11-0.12); TL = 0.27 (0.25-0.29); PL = 0.53 FIGS 15-21

(15-18) Parosus hilaris Sharp; labium (15), platelike armature in hypopharynx (16), mentum (17), labrum (18). (19-21) P. unicoloratus sp. n.; male tergite IX (19), male sternite IX (20), male tergite X (21). Scale bar = 0.06 mm for 16, 0.1 mm for 15, 17, 18, 0.15 mm for 19-21.

(0.49-0.56); SL = 0.85 (0.78-0.91); SC = 0.83 (0.76-0.89); FB = 2.09 (1.92-2.26); BL = 3.73 (3.54-3.92) mm. Body strikingly 'bicoloured', with red and black parts alternating. Head dark brown to pitch black, pronotum red to medium brown, elytra dark brown. Abdomen red to medium brown, except segments VII-VIII, which are dark brown (also the posterior edge of sternite VI). Legs, mouthparts and antennae reddish medium brown, the antennae slightly darkening around the middle. Pubescence medium short and dense, somewhat longer and sparser on abdomen. Unpunctured areas remarkably separated from punctured ones.

Head and pronotum. Mid-antennal articles about as long as wide (antennomere 6 length:width = 0.072: 0.070 mm). Clypeus (Fig. 56) trapezoid, ratio of longitudinal distance of supraantennal prominence tip from eyefront to the same from clypeal front = 0.44-0.57. Infraocular ridge (Fig. 59) rather strong (especially anteriorly), ending in a short, shiny keel at the posterior edge of the eye. Temple rather straight anteriorly, most curved in last third (slightly angled). Pronotum (Fig. 57) with maximum width 1.70-1.78x base width, sides gently curved anteriorly, a little bit straight in posterior third, anterior angles rather sharp. Clypeus and supraantennal ridges shiny and unpunctured. Frontoclypeal groove very shallow, reached by umbilicate puncture field of vertex. Posterior half of vertex very shallowly impressed, at middle of vertex a shinier (more sparsely punctured) transversal line. Anterior half of pronotal midline (except a very small area behind the anterior margin) deeply impressed, unpunctured, forms a posteriorly directed arrowhead shape (with scabrous microsculpture in it). Posterior half as a slightly elevated, unpunctured, shiny stripe, along its sides, two longitudinal depressions (running in 3/4 of total length). Laterad, two longitudinally elongate areas a little elevated and a tiny bit shinier. The pronotal sides with a trace of impression around middle. Head with about 34 'longitudinal' puncture lines, pronotum with about 30 'longitudinal' puncture lines, a small area at mid-vertex unpunctured.

Elytra and abdomen. Elytra (Fig. 58) dilating posteriorly, with two small, longitudinal impressions behind scutellum. Medially serrate fringe absent on hind margin of tergite VII (Fig. 25). Head, pronotum and elytra with similarly sized punctures, elytral punctation not umbilicate, interspaces about 4/5-1/1 (or more) of puncture diameters. Bases of tergites (posterior to basal ridges) with fine transversal coriaceous microsculpture, segments almost without punctation. Aedeagus as in Fig. 41.

ETYMOLOGY: The species is named after the peculiar colour pattern of the specimens.

COMPARATIVE NOTES: From the other three similarly sized 'bicoloured' species (P. hilaris, P. rossii , P. taliaferroae ) it differs by the dark abdominal segments being VII and VIII (also the posterior edge of sternite VI), whereas in P. hilaris and P. taliaferroae the dark ones are tergites V-VI (the sternites are not dark!) and P. rossii has only an occasional lighter abdominal base but always dark abdominal apex. Such bright and contrasting colours do not occur in the other two cross-striped species, also their shoulders are lighter (similar to the rest of the elytra in P. bicoloratus ), and their antennae are less elongate. This species differs from P. hilaris by the absence of the medially serrate fringe on the hind margin of tergite VII (while P. taliaferroae also lacks the fringe).

FIGS 22-31

(22-24) Antenomeres 4-8. Parosuslongicornis sp. n. (22), P. longipennis sp. n. (23), P. portobelo sp. n. (24). (25-31) Median part of palisade fringe on tergite VII. P. bicoloratus sp. n. (25), P. taliaferroae sp. n. (26), P. campbelli sp. n. (27), P. gigantulus sp. n. (28), P. unicoloratus sp. n. (29), P. longipennis sp. n. (30), P. brasilianus sp. n. (31). Scalebar = 0.05 mmfor 25, 26, 30, 0.07 mm for 27, 29, 31, 0.1 mm for 23, 28, 0.12 mm for 24, 0.24 mm for 22.

DISTRIBUTION: The species is known only from Ecuador (Pichincha Prov.).

BIONOMICS: Specimens were collected by pyrethrum fogging of a fungusy log and from dead vegetation in trees.