Stenotarsus guatemalae Arrow

Arriaga-Varela, Emmanuel, Zaragoza-Caballero, Santiago, Tomaszewska, Wioletta & Navarrete-Heredia, Jose Luis, 2013, Preliminary review of the genus Stenotarsus Perty (Coleoptera: Endomychidae) from México, Guatemala and Belize, with descriptions of twelve new species, Zootaxa 3645 (1), pp. 1-79 : 16-17

Stenotarsus guatemalae Arrow

(Figs. 18, 43, 57, 93, 161, 206–207, 260)

Stenotarsus guatemalae Arrow, 1920: 51 . Blackwelder 1945: 439; Strohecker 1953: 53; Shockley et al. 2009a: 82. Stenotarsus adumbratus Gorham, 1890: 140 (not Gorham, 1873: 63).

Diagnosis. This species resembles Stenotarsus sallaei Gorham and brown specimens of S. oblongulus Gorham , based on its rather oblong and uniformly brown body and pronotum with small, rounded or weakly elongate foveae ( Figs. 93, 104 , 110 ). Stenotarsus guatemalae can be distinguished by having terminal antennomere widening apically and without angles or protuberances on lateral margins ( Fig. 57 ), metatibia linear, gradually widened apically ( Fig. 162 ), male abdominal ventrite I without protuberances, and median lobe rather flattened, slightly bent externally, in ventral view ( Fig. 207 ) and widened apically, in lateral view ( Fig. 206 ).

Description of males. Body 3.6–4.7 mm long, long oval, moderately convex (Fig. 18), 1.76–1.84X as long as wide, 2.94–3.03X as long as high. Uniformly dark brown except antennomeres 8–11 black, 6–7 infuscate. Densely covered with long, suberect, light coppery to golden setae.

Head: Clypeus widely transverse, 2.5X wider than long. Terminal labial palpomere narrow, acuminate and narrowly truncate apically. Interocular distance 0.72X as wide as head. Antenna rather long and slender ( Fig. 57 ), 0.48X as long as body; scape 1.6X as long as wide, 1.7X longer than pedicel; pedicel 1.2X longer than wide; third antennomere 1.2X as long as wide, 1.2X as long as pedicel; fourth 1.7X as long as wide, 1.5X as long as pedicel; fifth 1.6X as long as wide, 1.7X as long as pedicel; sixth subequal to fourth; seventh 1.5X as long as wide, 1.7X as long as pedicel; eighth 1.1X as long as wide, 1.5X longer than pedicel; antennal club 0.39X as long as total antennal length, with segments almost symmetrical; ninth antennomere weakly widening apically, 1X as long as wide, 2X as long as pedicel; tenth weakly widening apically, 0.9X as long as wide, 2X as long as pedicel; terminal antennomere rather ovoid, 1.5X as long as wide, 3.8X as long as pedicel.

Prothorax: Pronotum widest at base, transverse ( Fig. 93 ), 2.02–2.17X wider than long, 1.85–1.89X wider at base than at front angles, 2.11–2.13X wider than head. Sides convergent to front angles. Front angles produced, briefly acute and rounded at tip. Hind angles distinctly acute. Anterior margin narrow, flat. Lateral margins weakly raised, moderately wide, weakly narrowing posteriorly; width of margin at base 1/3 of the distance between basal pore and hind angle; area between marginal line and pronotal edge flat. Disc moderately convex, finely and closely punctate. Longitudinal sulci moderately deep, narrowing anteriorly, short, slightly convergent. Basal pores small, rounded. Basal sulcus absent. Pronotal base hardly lobed medially, converging near scutellum. Prosternal process moderately wide at base, gently widened posteriorly ( Fig. 43 ); as wide as longitudinal procoxal diameter apically. Pterothorax: Scutellum triangular, moderately large, 1.92X wider than long, 0.17X as wide as pronotum. Elytra 2.35–3.21 mm long, 1.18X longer than wide, 3.40–3.50X longer and 1.3–1.4X wider than pronotum; long ovoid, widest at basal third, then roundly convergent to rounded apex. Moderately densely punctate with foveolate punctures rather small and shallow, separated by 2.5–5.0 diameters, sparser and shallower apically and near scutellum. Humerus moderately prominent. Epipleuron at base, 0.8X as wide as intercoxal process of metaventrite. Mesoventrite deeply excavated in front; bearing small setose pores laterally; mesoventral process slightly longer than longitudinal coxal diameter, without medial carinae. Metaventrite moderately convex, without modification on the anterior margin; with pair of small setose pores of approximately same diameter posterior to each mesocoxa. Metepisternum with small setose pore.

Legs: moderately long and slender ( Fig. 161 ). Trochanters simple. Meso- and metafemora bearing moderately long decumbent setae. Meso- and metatibiae slender; metatibia as long as metafemur, 0.34X as long as elytra, gradually widening apically, linear, unarmed. Metatarsus 0.65X as long as metatibia; second tarsomere produced and lobed, 2.0X as wide apically as fourth tarsomere at midlength.

Abdomen: ventrite I almost as long as metaventrite ( Fig. 43 ), slightly shorter than ventrites II–V combined, with sparse, shallow, coarse foveolate punctation, without protuberances. Ventrite V 1.7X longer than IV, rounded apically; ventrite VI rounded apically. Tergite VIII truncate posteriorly. Median lobe slender, curved, apex bent externally, in ventral view ( Fig. 207 ), weakly widening towards the oblique apex, in lateral view ( Fig. 206 ). Tegmen with moderately large submembranous tegminal plate.

Description of female. Female unknown.

Sexual dimorphism. Unknown.

Variation. The specimen from Costa Rica (4.7 mm) is larger than the holotype (3.6 mm).

Material examined. Types. Lectotype of Stenotarsus guatemalae Arrow (present designation) (male): Syntype [round, blue bordered label] / Type H. T. [round, red bordered label] / Tactic, Vera Paz, Champion / Stenotarsus guatemalae , type, Arrow / B.C.A., VII, Stenotarsus [p] adumbratus Gorh. [h] / S. adumbratus, Gorh. (NHM).

Other material. Costa Rica, Prov. San José, Puriscal. P.N. La Cangreja. Send. Ecotrópica. 300–400 13 Jul 2004. D. Briseño. L.N. 185736 496067. 77719 / INBIO00386332, INBIOCRI, Costa Rica (1 male: INBIO).

Distribution. COSTA RICA: San José; GUATEMALA: Alta Verapaz ( Fig.260 ).

Biological Notes. Altitudinal range: 300–1380 m.

Remarks. This species is recorded from Costa Rica for the first time.

Figures

FIGURES 90 – 104. Pronotum of Stenotarsus spp. 90) S. cortesi; 91) S. exiguus; 92) S. globosus; 93) S. guatemalae; 94) S. incisus; 95) S. kafkai; 96) S. latipes, S. molgorae; 97) S. lemniscatus; 98) S. marginalis; 99) S. mesoamericanus; 100) S. mexicanus; 101) S. militaris; 102) S. monterrosoi; 103) S. nigricans; 104) S. oblongulus.

FIGURES 105 – 114. Pronotum of Stenotarsus spp. 105) S. ovalis; 106) S. parallelicornis; 107) S. raramuri; 108) S. rubrocinctus; 109). S. rulfoi; 110) S. sallaei; 111) S. shockleyi; 112) S. smithi; 113) S. spiropenis; 114) S. thoracicus.

FIGURES 54 – 71. Right antennae of Stenotarsus spp. 54) S. cortesi; 55) S. exiguus; 56) S. globosus, S. rubrocinctus; 57) S. guatemalae; 58) S. incisus; 59) S. kafkai; 60) S. latipes; 61) S. lemniscatus; 62) S. marginalis; 63) S. mesoamericanus; 64) S. mexicanus; 65) S. militaris; 66) S. molgorae; 67) S. monterrosoi; 68) S. nigricans; 69) S. oblongulus; 70) S. ovalis; 71) S. parallelicornis.

FIGURES 158 – 173. Hind legs of male Stenotarsus spp. 158) S. cortesi; 159) S. exiguus; 160) S. globosus; 161) S. guatemalae; 162) S. incisus; 163) S. kafkai; 164) S. latipes; 165) S. lemniscatus; 166) S. marginalis; 167) S. mesoamericanus; 168) S. mexicanus; 169) S. militaris; 170) S. molgorae; 171) S. monterrosoi; 172) S. nigricans; 173) S. oblongulus.

FIGURES 200 – 223. Lateral and ventral view of median lobe of edeagus of Stenotarsus spp. 200 – 201) S. cortesi; 202 – 203) S. exiguus; 204 – 205) S. globosus, S. raramuri, S. rubrocinctus, S. shockleyi; 206 – 207) S. guatemalae; 208 – 209) S. incisus; 210 – 211) S. kafkai, S. mexicanus; 212 – 213) S. latipes; 214 – 215) S. lemniscatus; 216 – 217) S. marginalis; 218 – 219) S. mesoamericanus; 220 – 221) S. militaris; 222 – 223) S. molgorae.

FIGURES 43 – 49. 43 – 47. Habitus in ventral view of Stenotarsus spp. 48 – 49 Habitus in lateral view of Stenotarsus spp. 43) S. guatemalae; 44) S. kafkai; 45) S. nigricans; 46) S. militaris; 47) S. thoracicus; 48) S. incisus; 49) S. oblongulus.

FIGURES 260 – 262. Distributional maps of Stenotarsus spp. 260) S. guatemalae (C), S. marginalis (S); 261) S. kafkai (C), S. mexicanus (S), S. nigricans (T); 262) S. latipes (C), S. shockleyi (S). Yellow circles (C), red squares (S), blue triangles (T).