Stenotarsus monterrosoi, Arriaga-Varela, Emmanuel, Zaragoza-Caballero, Santiago, Tomaszewska, Wioletta & Navarrete-Heredia, Jose Luis, 2013

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 : 30-32

Stenotarsus monterrosoi sp. nov.

( Figs. 29 , 67 , 85 , 102 , 170 , 224 –225, 252 , 263 ) Diagnosis. This species resembles Stenotarsus smithi Gorham by its small size (3–4 mm), and body uniformly brown ( Figs. 29 ), but can be distinguished from it by the structure of the median lobe, which is of uniform width throughout, in ventral view ( Figs. 225 ), and by the larger body size of S. smithi (3.75–4.15 mm), shorter antennae, 0.33X as long as body ( Fig. 67 ), and by the second tarsomere not widened apically.

Description of males. Body 3.75–3.85 mm long, short oval, moderately convex, small ( Fig. 29 ), 1.7X as long as wide, 2.85–2.90X as long as high. Uniformly ferruginous-brown except antennal club black. Densely covered with long, suberect, golden setae.

Head: Clypeus transverse, 1.85X wider than long. Terminal labial palpomere narrow, acuminate, narrowly truncate apically. Interocular distance 0.67X as wide as head. Antenna short and slender ( Fig. 67 ), 0.33X as long as body; scape 1.4X as long as wide, 2X longer than pedicel; pedicel as long as wide; third antennomere 1.3X as long as wide, 1.1X as long as pedicel; fourth 1.4X as long as wide, 1.2X as long as pedicel; fifth and sixth subequal to fourth; seventh 1.1X as long as wide, 1.2X as long as pedicel; eighth subequal to seventh in dimensions but widened distally; antennal club 0.37X as long as total antennal length, with segments almost symmetrical; ninth antennomere widened apically, 0.7X as long as wide, 1.6X as long as pedicel; tenth strongly widened apically, 0.9X as long as wide, 2X as long as pedicel; terminal antennomere scarcely asymmetrical, subovate, widest at apical 2/3, 1.1X as long as wide, 2.7X as long as pedicel.

Prothorax: Pronotum widest at base, transverse ( Fig. 102 ), 2.0X wider than long, 2.4X wider than head, 2.15X wider at base than at front angles. Sides continuously rounded to front angles. Front angles slightly produced, briefly obtuse, narrowly rounded at tip. Hind angles right-angled. Anterior margin narrow, very scarcely arcuate medially. Lateral margins raised; moderately wide, weakly narrowing posteriorly; width of margin at base1/3 of the distance between basal pore and hind angle; area between marginal line and pronotal edge weakly concave. Disc moderately convex, finely and closely punctate. Longitudinal sulci rather feeble, short, weakly curved medially. Basal pores small, slightly elongate. Basal sulcus not present. Pronotum base convergent, flat near scutellum. Prosternal process narrow at base, strongly widened posteriorly; as wide as longitudinal procoxal diameter apically.

Pterothorax: Scutellum triangular, small, 1.8X wider than long, 0.14X wider than pronotum. Elytra 2.5 mm long, 1.1X longer than wide, 3.0X longer and 1.35X wider than pronotum; ovoid, widest near basal third, then roundly converging to the weakly acuminate apex; moderately densely punctate with foveolate punctures moderately large and deep, separated by 2–4 diameters, sparser and shallower apically. Humerus moderately prominent. Epipleuron at base 0.8X as wide as intercoxal process of metaventrite. Mesoventrite deeply excavated in front; mesoventral process as wide as longitudinal coxal diameter, without medial carinae. Metaventrite moderately convex, without modifications near the anterior margin ( Fig. 85 ); with pair of moderately large setose pores of approximately same diameter posterior to each mesocoxa. Metepisternum with small setose pore.

Legs: short and slender ( Fig. 170 ). Trochanters simple. Meso- and metafemora rather stout, widest at midlength; meso- and metafemora unarmed; metafemuras long as mesofemur, bearing moderately long decumbent setae. Meso- and metatibiae very slender; metatibia scarcely shorter than metafemur, 0.3X as long as elytra; gently widened apically, linear, unarmed. Metatarsus 0.66X as long as metatibia; second tarsomere produced and narrow, as wide apically as fourth tarsomere at midlength.

Abdomen: ventrite I slightly longer than metaventrite and as long as ventrites II–V combined, with sparse large foveolate punctation, without protuberances. Ventrite V markedly longer than IV, with apex briefly truncate. Ventrite VI rounded apically. Tergite VIII truncate. Median lobe small, moderately narrow, curved ( Figs. 224–225 ). Tegmen with moderately large submembranous tegminal plate.

Description of females. Body 3.75–4.15 mm long, 1.77–1.80X as long as wide, 2.65X as long as high. Antenna 0.32–0.33X as long as body. Pronotum 2.08–2.11X wider than long, 2.27–2.35X wider at base than at front angles, 2.45–2.5X wider than head. Elytra 2.35–2.58 mm long, 1.1X longer than wide, 2.89–2.94X as long as pronotum, 1.24–1.26X wider than pronotum. Metatibia, 0.30X as long as elytra. Metatarsus 0.65–0.69X as long as metatibia. Ovipositor with proctiger rounded, coxites wide, without styli ( Fig. 252 ).

Sexual dimorphism. No significant sexual dimorphism was found.

Material examined. Types. Holotype (male): Bobas, Guat, May 1924 / W.M. Mann collector (NMNH); Paratypes: same data as holotype: (4 males, 5 females: NMNH).

Distribution. GUATEMALA: Izabal ( Fig. 263 ).

Biological Notes. Period of activity: collected in May.

Etymology. This small–sized species from Guatemala is dedicated to the late Guatemalan author Augusto Monterroso, who mastered the art of short narrative.

Remarks. The locality written in the label as “Bobas” in Guatemala, could not be found. This name may be a misspelling of Bobos, a small town and river in Izabal department.

Figures

FIGURES 26 – 37. Habitus in dorsal view of Stenotarsus spp. Scale bar = 1 mm. 26 – 27) S. militaris; 28) S. molgorae; 29) S. monterrosoi; 30) S. nigricans; 31 – 32) S. oblongulus; 33) S. ovalis; 34) S. parallelicornis; 35) S. raramurii: 36) S. rubrocinctus; 37) S. rulfoi.

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 79 – 89. 79 – 83. Pronotum of Stenotarsus spp. 84 – 89. Intercoxal process of male metaventrite of Stenotarsus spp. 79) S. marginalis; 80) S. mexicanus; 81) S. oblongulus; 82) S. o valis; 83) S. spiropenis; 84) S. incisus; 85) S. monterrosoi; 86) S. oblongulus; 87) S. ovalis; 88) S. rubrocinctus; 89) S. shockleyi.

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 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 224 – 243. Lateral and ventral view of median lobe of edeagus of Stenotarsus spp. 224 – 225) S. monterrosoi; 226 – 227) S. nigricans; 228 – 229) S. oblongulus; 230 – 231) S. ovalis; 232 – 233) S. parallelicornis; 234 – 235) S. rulfoi; 236 – 237) S. sallaei; 238 – 239) S. smithi; 240 – 241) S. spiropenis; 242 – 243) S. thoracicus.

FIGURES 244 – 256. Female genitalia structures of Stenotarsus spp. 244) Ovipositor with spermatheca and accessory gland of S. spiropenis, dorsal. 245 – 256. terminal part of ovipositor, dorsal. 245) S. cortesi; 246) S. exiguus; 247) S. globosus, S. raramuri, S. rubrocinctus, S. shockleyi; 248) S. incisus; 249) S. latipes; 250) S. mesoamericanus; 251) S. mexicanus; 252) S. monterrosoi; 253. S. nigricans. 254. S. ovalis. 255. S. sallaei. 256. S. thoracicus.

FIGURES 263 – 265. Distributional maps of Stenotarsus spp. 263) S. lemniscatus (C), S. monterrosoi (S); 264) S. militaris (C), S. smithi (S); 265) S. ovalis (C), S. molgorae (S), S. thoracicus (T). Yellow circles (C), red squares (S), blue triangles (T).