Stenotarsus rubrocinctus Gerstaecker

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 : 39-41

Stenotarsus rubrocinctus Gerstaecker

( Figs. 36 , 56 , 88 , 108 , 152 , 177 , 196 , 204 –205, 247 , 259 )

Stenotarsus rubrocinctus Gerstaecker, 1858: 324 ; Gorham 1890: 137; Blackwelder 1945: 440; Strohecker 1953: 56; Arriaga- Varela et al. 2007: 15; Shockley et al. 2009a: 85.

Diagnosis. This species is most similar to S. globosus , S. raramuri sp. nov. and S. shockleyi sp. nov., sharing similar antennal structure ( Figs. 56 , 72, 75 ), genitalia of both sexes ( Fig. 204–205 ; 247), and the following features of the male: metaventrite with a concavity between mesocoxae ( Figs. 88–89 ), metatibia with a row of small tubercles on medial margin ( Figs. 145 , 160 , 177–178, 181 ), and metafemur with a tooth on medial margin near trochanter ( Figs. 150–153 ). However, S. rubrocinctus can be separated from these species by body of medium size (5.4–6.6 mm), antenna red with antennomeres 7–11 black, pronotum red with a large triangular black spot reaching anterior margin and not surpassing basal pores at base ( Fig. 36 ), elytra with foveolate punctures rather small, and male metafemur with tooth large, curved and pointed at tip ( Fig. 152 ).

Description of males. Body 5.4–6.5 mm long, short oval, markedly convex ( Fig. 36 ), 1.67–1.73X as long as width, 2.8–2.9X as long as height. Contrastly colored with head orange to red; antenna orange-red with antennomeres 7–11 black, antennomere 6 may be infuscated; pronotum red with a large triangular black mark reaching anterior margin and not surpassing basal pores at base, margins and angles orange-red; hypomeron and prosternum red; scutellum black or rarely red; elytra red, each elytron with a large, oval, black macula; epipleura red;meso and metathorax black with mesoventrite infuscate or red at least medially; legs orange-red; abdomen orange-red with first ventrite black margined by red. Densely covered with long, suberect, golden setae; with darker setae in the black parts of elytra and pronotum.

Head: Clypeus transverse, 1.8–2.0X wider than long. Terminal labial palpomere narrow, acuminated, narrowly truncate apically. Interocular distance 0.66–0.68X as wide as head. Antenna moderately long and slender ( Fig. 56 ), 0.42X as long as body; scape 1.4X as long as wide, 1.8X longer than pedicel; pedicel 1.1X longer than wide; third antennomere 1.6X as long as wide, 1.4X as long as pedicel; fourth subequal to third; fifth 2X as long as wide, 1.7X as long as pedicel; sixth 1.9X as long as wide, 1.6X as long as pedicel; seventh subequal to sixth; eighth 1.3X as long as wide, 1.5X longer than pedicel; antennal club 0.4X as long as total antennal length, with segments almost symmetrical; ninth widened apically, 1.3X as long as wide at apical margin, 2X as long as pedicel; tenth widened apically, 1.2X as long as wide, 2.2X as long as pedicel; terminal antennomere slightly asymmetrical, subrectangular, slightly widening apically, 1.6X as long as wide, 3.6X as long as pedicel.

Prothorax: Pronotum widest at base, transverse ( Fig. 108 ), 2.0–2.2X wider than long, 2.3–2.4X wider than head, 1.9–2.0X wider at base than at front angles. Sides weakly convergent in posterior half, then weakly rounded to front angles. Front angles produced, right-angled to briefly acute, narrowly rounded at tip. Hind angles weakly acute. Anterior margin narrow, slightly arcuate medially. Lateral margins moderately raised, weakly accentuating anteriorly; moderately wide, weakly narrowing posteriorly, more strongly close to base; width of margin at base almost 1/4 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 moderately deep, lacking anteriorly, short, weakly curved medially. Basal pores large, curved, oblique. Basal sulcus only impressed near pores. Pronotal base lobed medially. Prosternal process narrow at base, widened posteriorly; scarcely narrower than longitudinal procoxal diameter apically.

Pterothorax: Scutellum triangular, moderately large, 1.7–1.8X wider than long, 0.18–0.19X as wide as pronotum. Elytra 3.7–4.3 mm long, 1.1–1.3X longer than wide, 3.40–3.45X longer and 1.43–1.52X wider than pronotum; ovoid, widest near basal third, then roundly converging to acuminate apex; moderately densely punctate with foveolate punctures rather small and shallow, separated by 1.5–4.0 diameters, sparser and shallower apically. Humerus moderately prominent. Epipleuron at base 0.8X as wide as the 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 weakly convex, with transverse, more densely pubescent concavity on intercoxal process between mesocoxae ( Fig. 88 ); with pair of small setose pores of approximately same diameter posterior to each mesocoxa. Metepisternum with small setose pore.

Legs: long and slender ( Fig. 177 ). Trochanters simple. Meso- and metafemora rather slender, widest before midlength; mesofemur unarmed; metafemur slightly longer than mesofemur, bearing moderately long decumbent setae, with a large, well developed tooth, pointed at tip, in the base of medial margin. Meso- and metatibiae very slender; metatibia as long as metafemur, 0.40–0.45X as long as elytra, very weakly and gradually widened apically, slightly bent in apical third, with a row of small tubercles on medial margin. Metatarsus 0.4X as long as metatibia; second tarsomere produced and lobed, 2X wider apically than fourth tarsomere at midlength.

Abdomen: ventrite I almost as long as metaventrite and slightly shorter than ventrites II–V combined, with sparse foveolate punctation posterior to metacoxae, without protuberances. Ventrite V scarcely longer than IV, with apex truncate. Ventrite VI rounded apically. Tergite VIII weakly truncate. Median lobe slender, curved, gradually narrowed with apical crest, in ventral view ( Fig. 205 ), widened apically, in lateral view ( Fig. 204 ). Tegmen with moderately large submembranous tegminal plate ( Fig. 196 ).

Description of females. Body 5.6–6.6 mm long, 1.60–1.63X as long as wide, 2.53–2.62X as long as high. Antenna 0.38–0.40X as long as body. Pronotum 2.16–2.21X wider than long, 1.90–1.98X wider at base than at front angles, 2.15–2.38X as wide as the head. Elytra 3.75–4.5 mm long, 1.08–1.10X longer than wide, 3.64–3.79X longer and 1.47–1.58X wider than pronotum. Metaventrite moderately convex, without a concavity or other modification, on the anterior margin. Legs long and slender. Metafemur unarmed. Metatibia 0.30–0.33X as long as elytra, linear, unarmed. Metatarsus 0.58–0.63X as long as metatibia. Ovipositor with proctiger rounded, coxites wide, without styli ( Fig. 247 ).

Sexual dimorphism. Males have a concavity on metaventrite, the metatibia with a row of small tubercles and metafemur with a tooth. Females have proportionally larger elytra and shorter antennae and legs.

Variation. No significant variation was found.

Material examined. Types. Lectotype of Stenotarsus rubrocinctus Gerstaecker (present designation) (male): Mexico [blue label] / Mexico / Zool. Mus. Polonicum, Warszawa 12/45 / SYNTYPE MIZ 103153 [red label] / rubrocinctus Gerstaecker, Mex. (MIZ); Paralectotype (male): Mexico [blue label] / Zool. Mus. Polonicum, Warszawa 12/45 / SYNTYPE MIZ 103154 [red label] (MIZ); Paralectotype (male): 21859 / Hist. Coll. ( Coleoptera ), Nr 21859, Stenotarsus rubrocinctus Gerstaecker , Mexico, Dohrn. Zool. Mus. Berlin [green label] / rubrocinctus Gerstaecker , Mexico, Dohrn [green label] / SYNTYPUS Stenotarsus rubrocinctus Gerstaecker, 1858 . Labelled by MNB 2008 (MNB).

Other material. Hidalgo, 45 Km. Tlanchinol carr. Molango-Huejutla, en tronco podrido, 3/III/79, R. Terrón (10 males, 13 females: CNIN); Querétaro, Landa de Matamoros, Neblinas, 9.VIII.2002, Alt. 600 m, en tronco podrido, Q. Santiago y L. Delgado (1 male: IEXA); Veracruz, Huayacocotla, Carr. a Zicaltepec, La Selva, 2112 m, Bosque de Encino-Pino, N 20o33’19.1’’ W 98 o29’14.6’’. Troncos podridos. 26-VI-2003. Asiain, Canales y Márquez (1 female: UAEH).

Distribution. MEXICO: Hidalgo, Querétaro, Veracruz ( Fig. 259 ).

Biological Notes. Altitudinal range: 600–2400 m. Period of activity: March and July–August. Habit: rotten log.

Remarks. Stenotarsus rubrocinctus bears a striking resemblance to S. globosus Guérin-Méneville , due to their shared contrastly colored body (Figs. 16, 36) and rather large metafemoral tooth in males ( Figs. 150, 152 ). However, while members of S. globosus show a significant variation in coloration with some specimens having antennae, pronotum and legs completely black, all members of S. rubrocinctus have legs completely red, antenna only with articles 7–11 black, and pronotum with black triangular macula, not surpassing basal pores.

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 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 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 174 – 185. 174 – 183. Hind legs of male Stenotarsus spp. 184 – 185. Hind legs of female Stenotarsus spp. 174) S. ovalis; 175) S. parallelicornis; 176) S. raramuri; 177) S. rubrocinctus; 178) S. rulfoi; 179) S. sallaei; 180) S. shockleyi; 181) S. smithi; 182) S. spiropenis; 183) S. thoracicus; 184) S. exiguus; 185) S. globosus.

FIGURES 196 – 199. Aedeagus of Stenotarsus spp. 196) S. globosus, S. raramuri, S. rubrocinctus, S. shockleyi; 197) S. militaris; 198) S. oblongulus; 199) S. spiropenis.

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.

FIGURES 72 – 78. Right antennae of Stenotarsus spp. 72) S. raramuri; 73) S. rulfoi; 74) S. sallaei; 75) S. shockleyi; 76) S. smithi; 77) S. spiropenis; 78) S. thoracicus.

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.