Stenotarsus mesoamericanus, 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 : 25-26

Stenotarsus mesoamericanus sp. nov.

(Figs. 24, 63, 99, 128, 167, 218–219, 250, 257)

Diagnosis. This species is similar to Stenotarsus cortesi sp. nov. and S. parallelicornis sp. nov. in antennal structure, with antennomeres 3–8 as long as wide, and club slightly longer than the rest of antenna, with its articles elongate and scarcely widened apically ( Figs. 54, 63, 71 ). However, S. mesoamericanus can be distinguished by having the pronotum and elytra red, each with a large, central, black macula (Fig. 24) and by the shape of median lobe, which is more strongly widened apically, in lateral view ( Fig. 218 ).

Description of males. Body 5.4 mm long, moderately long oval, markedly convex (Fig. 24), 1.75X as long as wide, 2.6X as long as high. Contrastly colored with head red, antenna orange-red with club black; pronotum ferruginous red with a subtriangular to semicircular black macula, not extending beyond basal pores at base; elytra red with a large, oval black macula; epipleura red; venter uniformly ferruginous red. Densely covered with long, suberect, golden setae.

Head: Clypeus transverse, 2X wider than long. Terminal labial palpomere narrow, acuminate, narrowly truncate apically. Interocular distance 0.64X as wide as head. Antenna moderately long and distinctly stout ( Fig. 63 ), 0.42X as long as body; scape 1X as long as wide, 1.6X longer than pedicel; pedicel 1X longer than wide; third antennomere 1.3X as long as wide, 1.1X as long as pedicel; fourth 1.3X as long as wide, 1.1X as long as pedicel; fifth 1.1X as long as wide, 1.2X as long as pedicel; sixth 1.1X as long as wide, 1.2X as long as pedicel; seventh 1.1X as long as wide, 1.1X as long as pedicel; eighth 0.8X as long as wide, 1X as long as pedicel; antennal club 0.54X as long as total antennal length, with segments almost symmetrical and parallel sided; ninth antennomere scarcely widened apically, 1.3X as long as wide, 2.9X as long as pedicel; tenth scarcely widened apically, 1.4X as long as wide, 3.1X as long as pedicel; terminal antennomere markedly elongate, nearly parallel sided, 2.1X as long as wide, 5.2X as long as pedicel.

Prothorax: Pronotum widest at base, transverse ( Fig. 99 ), 2.35X wider than long, 2.35X wider at base than at front angles, 2.45X wider than head. Sides convergent in basal half then weakly rounded to front angles, with a small tooth at midlength. Front angles rather strongly produced, slightly acute, rounded at tip. Hind angles rightangled. Anterior margin narrow, scarcely arcuate medially. Lateral margins markedly raised, markedly wide; width of margin at base 1/3 of the distance between basal pore and hind angle; area between marginal line and pronotal edge flat to slightly concave. Disc moderately convex, finely and closely punctate. Longitudinal sulci rather shallow, short, curved. Basal pores moderately large, elongate and oblique. Basal sulcus impressed only near pores. Pronotal base weakly lobed, slightly emarginate near scutellum. Prosternal processnarrow at base, strongly widened posteriorly ( Fig. 128 ); narrower than longitudinal procoxal diameter apically.

Pterothorax: Scutellum triangular, small, 1.5X wider than long, 0.17X as wide as pronotum. Elytra 3.75 mm long, 1.2X longer than wide, 4.0X longer and 1.38X wider than pronotum; ovoid, widest near basal third, then roundly converging to the slightly acuminate apex; moderately vaguely punctate with foveolate punctures rather small and shallow, separated by 4–5 diameters, coarser near humeri, slightly sparser and shallower apically. Humerus moderately prominent. Epipleuron at base 0.75X as wide as intercoxal process of metaventrite. Mesoventrite deeply excavated in front; bearing small setose pores laterally; mesoventral process as wide as the longitudinal coxal diameter, without medial carinae. Metaventrite markedly convex, without modifications near 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 rather stout ( Fig. 167 ). Trochanters simple. Meso- and metafemora moderately stout, widest at midlength, unarmed; metafemur slightly longer than mesofemur, bearing moderately long decumbent setae. Meso- and metatibiae moderately stout; metatibia as long as metafemur, 0.31X longer than elytra; gradually widened apically, linear, medial margin unarmed. Metatarsus 0.55X as long as metatibia; second tarsomere produced and narrow, 1.2X wider apically than fourth tarsomere at midlength.

Abdomen: ventrite I slightly longer than metaventrite and as long as ventrites II–V combined, with moderately large foveolate punctation posterior to metacoxae, without protuberances. Ventrite V almost twice as long as IV, with apex briefly truncate. Ventrite VI rounded apically. Tergite VIII truncate. Median lobe large, moderately narrow, curved, width subequal to length, in ventral view ( Fig. 219 ); strongly widened apically, in lateral view ( Fig. 218 ). Tegmen with moderately large submembranous tegminal plate.

Description of females. Body 4.0 mm long, 1.5X as long as wide, 2.3X as long as high. Antenna 0.41X as long as body. Pronotum 2.35X wider than long, 2.0X wider at base than at front angles, 2.3X wider than head; tooth on lateral edge poorly developed. Elytra 3.07 mm long, 1.1X longer than wide, 3.73X longer and 1.45X wider than pronotum. Metatibia 0.29X as long as elytra. Metatarsus 0.59X as long as metatibia. Ovipositor with proctiger very acuminate, narrowly rounded apically, coxites narrow, without styli ( Fig. 250 ).

Material examined. Types. Holotype (male): MÉXICO: Puebla, Xicotepec de Juárez, Hidroeléctrica Patla. Bosque mesófilo de montaña-cultivos. En hongos de troncos. 3-X-2003. E. Chanes col. (UAEH); Paratypes (females): same data as holotype: (UAEH); El Triunfo, 8-VII-1993, C. Mayorga (CNIN).

Distribution. MEXICO: Chiapas, Puebla ( Fig. 257 ).

Biological Notes. Habitat: Cloud forest-plantations. Habit: “dead log fungi”.

Etymology. The species epithet is based on Mesoamerica, the name given by anthropology scholars to the area extending from Central México to northern Central America.

Remark. The apex of the median lobe of the holotype is broken ( Fig. 218 ).

Figures

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 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 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 126 – 143. Thoracic structures of Stenotarsus spp. 126 – 133. Prosternal process. 134 – 136. Scutellum. 137 – 138. Mesoventrite. 139 – 140. Metepisternum. 141 – 143. Anterolateral part of metaventrite. 126) S. cortesi; 127) S. globosus, S. rubrocinctus; 128) S. meosamericanus; 129) S. oblongulus; 130) S. ovalis; 131) S. shockleyi; 132) S. spiropenis; 133) S. thoracicus; 134) S. globosus; 135) S. ovalis; 136) S. spiropenis; 137) S. nigricans; 138) S. spiropenis; 139) S. ovalis; 140) S. spiropenis; 141) S. marginalis; 142) S. nigricans; 143) S. spiropenis. PC. Procoxal cavity. PR. Procoxal rest. SP. Setose pore. MC. Mesocoxal cavity.

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 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 257 – 259. Distributional maps of Stenotarsus spp. 257) S. cortesi (C), S. mesoamericanus (S), S. parallelicornis (T); 258) S. exiguus (C), S. incisus (S); 259) S. globosus (C), S. rubrocinctus (S), S. raramuri. (T). Yellow circles (C), red squares (S), blue triangles.