Stenotarsus incisus, 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 : 17-19

Stenotarsus incisus sp. nov.

(Figs. 19, 48, 58, 84, 94, 155, 162, 188, 208–209, 248, 258)

Diagnosis. This species is distinguished from other species of the region by its small size (length 3.3–4.5 mm), body with constrasting coloration: pronotum and elytra dark red, each with a large black macula (Fig. 19), pronotum with lateral margins markedly wide, lacking tooth, basal pores small, slightly oblique ( Fig. 94 ), metaventrite of males with a deep longitudinal, medial excavation near the anterior margin ( Fig. 84 ) and legs with second tarsomere narrow, not widened apically ( Fig. 155 ).

Description of males. Body 3.3–3.4 mm long, short oval (Fig. 19), markedly convex ( Fig. 48 ), 1.7–1.8X as long as wide; 2.4X as long as high. coloration contrasting: head red, antenna uniformly black or with antennomeres 1–6 red or gradually infuscate; pronotum red with a large, black macula; elytra red, each with a large, oval, black macula; epipleura red; hypomeron and prosternum red; pterothorax black with mesoventrite red, or completely red; legs black or red. Densely covered with long, suberect, golden setae.

Head: Clypeus transverse, 2.0X wider than long. Terminal labial palpomere narrow, acuminate, narrowly truncate apically. Interocular distance 0.64X as wide as head. Antenna moderately long and slender ( Fig. 58 ), 0.37X as long as body; scape 1.2X as long as wide, 1.6X longer than pedicel; pedicel 1X longer than wide; third antennomere 1.2X as long as wide, 0.9X as long as pedicel; fourth 1.3X as long as wide, 1.1X as long as pedicel; fifth and sixth subequal to fifth; seventh 1.1X as long as wide, 0.9X as long as pedicel; eighth 0.9X as long as wide, 0.8X longer than pedicel; antennal club 0.45X as long as total antennal length with segments almost symmetrical; ninth antennomere widened apically, 0.9X as long as wide, 16X as long as pedicel; tenth widened apically, 0.9X as long as wide, 1.7X as long as pedicel; terminal antennomere symmetrical, subrectangular, 1.4X as long as wide, 3.1X as long as pedicel.

Prothorax: Pronotum ( Fig. 94 ) widest at base, markedly transverse, 2.3–2.4X wider than long, 2.1–2.2X wider at base than at front angles, 2.4X wider than head. Sides strongly convergent in basal half, then scarcely rounded to front angles. Front angles produced, right-angled, rounded at tip. Hind angles acute. Anterior margin narrow, scarcely arcuate medially. Lateral margins distinctly raised, flat to slightly concave; area between marginal line and pronotal edge flat; markedly wide, weakly narrowing posteriorly, more strongly near base; width of margin at base 2/5 of the distance between basal pore and hind angle. Disc moderately convex, finely and closely punctate. Longitudinal sulci rather feeble, short. Basal pores small, slightly elongate and oblique. Basal sulcus impressed only near pores. Pronotal base lobed medially. Prosternal process narrow at base, strongly widened posteriorly; as wide as longitudinal procoxal diameter apically.

Pterothorax: Scutellum triangular, small, 1.65–1.80X wider than long, 0.14X as wide as pronotum. Elytra 2.15–2.30 mm long, 1.18–1.25X longer than wide,3.4X longer and 1.18–1.25X wider than pronotum; ovoid, widest near basal third, then roundly converging to the weakly acuminate apex; moderately densely punctate with foveolate punctures rather small snd shallow, separated by 1.5–3.5 diameters, sparser and shallower apically. Humerus weakly 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 as wide as longitudinal coxal diameter, without medial carinae. Metaventrite markedly convex, with a deep longitudinal pit near anterior margin at midline ( Fig. 84 ); with a pair of small setose pores of approximately same diameter posterior to each mesocoxa. Metepisternum with small setose pore.

Legs: rather short and slender ( Fig. 162 ). Trochanters simple. Meso- and metafemora rather stout, widest at midlength,unarmed; metafemur as long as mesofemur, bearing moderately long decumbent setae. Meso- and metatibiae very slender; metatibia scarcely shorter than metafemur, 0.30–0.31X as long as elytra,very weakly widening apically, linear, unarmed. Metatarsus ( Fig. 155 ) 0.58–0.62X 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 rather stout, curved, strongly constricted near apical third, in ventral view ( Fig. 209 ); slightly sinuate, narrowing towards apex, in lateral view ( Fig. 208 ). Tegmen with moderately large and membranous tegminal plate.

Description of females. Body 3.5–4.5 mm long, 1.65–1.85X as long as wide, 2.4–2.5X as long as high. Antenna 0.35–0.38X longer than body. Pronotum 2.28–2.45X wider than long, 2.05–2.17X wider at base than atfront angles, 2.48–2.45X wider than head. Elytra 2.3–3.0 mm long, 1.1–1.2X longer than wide, 3.1–3.6X as long as pronotum, 1.20–1.33X wider than pronotum. Metaventrite without modifications near anterior margin. Metatibia 0.30X as long as elytra. Metatarsus 0.58–0.62X as long as metatibia. Ovipositor with proctiger truncate; coxites markedly wide, without styli ( Fig. 248 ).

Sexual dimorphism. Females lack the longitudinal fovea on metaventrite and have longer and wider elytra.

Variation. The paratypes from Quetzaltenango, Sto. Domingo Tepuxtepec and Tlapacoyan have ventral surfaces and legs completely red.

Material examined. Types. Holotype (male): MÉXICO: Chiapas, Ángel Albino Corzo, Reserva “El Triunfo”, Julio – 1991, Mesófilo, E. Guevara, col. / ex Russula mexicana / Stenotarsus marginalis Arrow, E. Arriaga-Varela det. 2006 (CZUG); Paratypes: same data as holotype (1 male, 2 females: CZUG); Quetzaltenango, Guat, V–9–45, E.J. Hambleton (1 female: NMNH); Oaxaca, Km 3 carr. Sto. Domingo Tepuxtepec-Juquila Mixes, 19-VIII-2003, Alt. 2000 m, Tr. Intercepción, Q. Santiago & L. Delgado (1 female: IEXA); Veracruz, Banderilla, La Martinica, 30.VIII.2001, en Lactarius sp. No. 43, Alt. 1550, L. Delgado col./ Stenotarsus marginalis Arrow, E. Arriaga-Varela det. 2006 (1 female: IEXA); Tlapacoyan, Ver., 18-IV- 1946, 800m., C. Bolivar (1 female: ENCB).

Distribution. GUATEMALA: Quetzaltenango; MEXICO: Chiapas, Oaxaca, Veracruz ( Fig. 258 ). Biological Notes. Altitudinal range: 800–2000 m. Habitats: cloud forest. Host fungi: Lactarius sp. and Russula mexicana (Agaricales: Russulaceae ). Collecting techniques: flight intercept trap. Etymology. The specific epithet refers to the longitudinal incision or pit in the metaventrite of males of this species.

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 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 144 – 157. Structure of hind legs of Stenotarsus spp. 144 – 149 Hind leg. 150 – 153. Base of male metafemur. 154 – 157. Metatarsus. 144) S. exiguus; 145) S. globosus; 146) S. latipes; 147) S. nigricans; 148) S. spiropenis; 149) S. ovalis; 150) S. globosus; 151) S. raramuri; 152) S. rubrocinctus; 153) S. shockleyi; 154) S. globosus; 155) S. incisus; 156) S. spiropenis; 157) S. oblongulus.

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 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 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.