Stenotarsus ovalis 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 : 35-36

Stenotarsus ovalis Arrow

( Figs. 2 , 33 , 70 , 82, 87 , 105 , 120 , 130, 135 , 149 , 174 , 230–231, 234 , 265 )

Stenotarsus ovalis Arrow, 1920: 50 . Blackwelder 1945: 440; Strohecker 1953: 55; Roubik & Skelley 2001: 256; Shockley et al. 2009a: 84.

Stenotarsus rotundus Arrow, 1920: 52 . Blackwelder 1945: 440; Strohecker 1953: 56; Synonymized by Roubik & Skelley 2001: 256.

Stenotarsus orbicularis Gorham, 1890: 134 (in part).

Stenotarsus pilatei Gorham, 1890: 135 (in part).

Diagnosis. This species is recognizable among all species of the region by the semicircular scutellum ( Fig. 135 ), elytral epipleuron wide, 1.2X wider at base than the anterior margin of metaventrite, by the males having a transverse, well defined oblong concavity near the anterior margin of metaventrite ( Fig. 87 ), and a small sharp tooth on hind margin of metatrochanter.

Description of males. Body 6.6– 5.4 mm long, short oval, moderately convex ( Fig. 33 ), 1.55–1.64X as long as wide, 3.0–3.1X as long as high. Uniformly reddish brown except antennomeres 6–11 which are black ( Fig. 2 ). Densely covered with long, suberect, golden to coppery setae.

Head: Clypeus moderately transverse, 1.7–1.8X wider than long. Terminal labial palpomere narrow, acuminate, narrowly truncate apically. Interocular distance 0.63–0.66X as wide as head. Antenna long and slender ( Fig. 70 ), 0.42–0.45X as long as body; scape 1.4X as long as wide, 1.9X longer than pedicel; pedicel 0.9X longer than wide; third antennomere 1.8X as long as wide, 1.7X as long as pedicel; fourth 2X as long as wide, 1.9X as long as pedicel; fifth 2X as long as wide, 2.1X as long as pedicel; sixth 1.8X as long as wide, 1.9X as long as pedicel; seventh subequal to sixth; eighth 1.4X as long as wide, 1.5X longer than pedicel; antennal club 0.35– 0.38X as long as total antennal length, with antennomeres almost symmetrical; ninth antennomere weakly widened apically, 1.2X as long as wide, 2.1X as long as pedicel; tenth widened apically, as long as wide, 2X as long as pedicel; terminal antennomere slightly asymmetrical, oblong, widest near midlength, 1.6X as long as wide, 3.7X as long as pedicel.

Prothorax: Pronotum ( Figs. 82 , 105 ) widest at base, markedly transverse and trapezoidal, 2.32–2.37X wider than long, 2.32–2.43X wider at base than at front angles, 2.60–2.68X wider than head. Sides rounded, strongly convergent to front angles. Front angles produced, right-angled or briefly obtuse, blunt at tip. Hind angles acute. Anterior margin narrow, very weakly arcuate medially. Lateral margins raised, markedly wide, narrowed near base; width of margin at base less than 1/3 of the distance between basal pore and hind angle; area between marginal line and pronotal edge flat to very weakly concave. Disc moderately convex, finely and closely punctate. Longitudinal sulci feeble, short and slightly convergent. Basal pores moderately large, slightly curved and oblique. Basal sulcus only impressed near pores. Pronotal base lobed medially. Prosternal process narrow at base, strongly widened posteriorly; slightly narrower than longitudinal procoxal diameter apically ( Fig. 130 ).

Pterothorax: Scutellum semicircular, rather small ( Fig. 135 ), 1.87X wider than long, 0.11–0.12X as wide as pronotum. Elytra 3.6–4.5 mm long, 1.03–1.08X longer than wide, 3.37–3.50X longer and 1.30–1.42X wider than pronotum; ovoid, widest near basal third, then roundly converging to the rounded apex; densely punctate with foveolate punctures rather large and deep, separated by 1.5–3.5 diameters ( Fig. 120 ), coarser posterior to humeri and sparser and shallower apically. Humerus moderately prominent. Epipleuron distinctly wide at base, 1.2X as wide as of 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 a transverse concavity of a well-defined oblong shape, more densely pubescent and infuscate, near the anterior margin ( Fig. 87 ); with pair of small setose pores of approximately same diameter posterior to each mesocoxa. Metepisternum with small setose pore.

Legs: long and slender ( Figs. 149 , 174 ). Pro- and mesotrochanters simple; metatrochanter with a small sharp tooth on basal margin. Meso- and metafemora markedly slender, widest barely before midlength, unarmed; metafemur slightly longer than mesofemur, bearing moderately long decumbent setae. Meso- and metatibiae very slender; metatibia as long as metafemur, 0.4X as long as elytra, very weakly and continuously widened apically, almost linear, with row of small tubercles on medial margin. Metatarsus 0.36–0.40X as long as metatibia; second tarsomere produced and lobed, 2.5X wider apically than fourth tarsomere at midlength.

Abdomen: ventrite I almost as long as metaventrite and ventrites II–V combined, with moderately dense foveolate punctation in anterior half, without protuberances. Ventrite V almost twice as long as IV, with apex rounded. Ventrite VI rounded apically. Tergite VIII truncate. Median lobe short, stout, curved, with an accessory process on external side, in lateral view ( Fig. 231 ); widening strongly towards apex, in lateral view ( Fig. 230 ). Tegmen with moderately large submembranous tegminal plate.

Description of females. Body 6.2– 5.6 mm long, 1.60–1.67X longer than wide, 3.04–3.17X longer than high. Antenna 0.36–0.38X as long as body. Pronotum 2.26–2.42X wider than long, 2.30–2.41X wider at base than at front angles, 2.56–2.65X as wide as the head. Elytra 3.75–4.25 mm long, 1.09–1.10X longer than wide, 3.46–3.63X longer and 1.37–1.43X wider than pronotum. Metaventrite without a concavity, or other modification, near the anterior margin. Legs with hind trochanters unarmed. Meso- and metatibiae without row of small tubercles. Metatibia as long as metafemur, 0.32–0.34X longer than elytra. Metatarsus 0.59–0.60X as long as metatibia. Ovipositor with proctiger slightly acuminate, blunt apically; coxites rather narrow, without styli ( Fig. 234 ).

Sexual dimorphism. Females lack the depression on intercoxal process of metaventrite, the sharp tooth on the metatrochanter and the row of tubercles on the medial margin of the metatibia. Male antennae and legs are considerably more elongate.

Variation. Specimens from Costa Rica and Panamá are slightly smaller (5.7– 5.4 mm).

Material examined. Mexico, coll. J. Flohr / Stenotarsus ovalis Arrow , det. H.F. Strohecker, from study of type. (1 male: MNB); 22.4, Cacao, Trece Aguas / Alta V. Paz, Guatemala / Schwartz & Barber coll. (1 male, 1 female: NMNH); 28.4, Cacao, Trece Aguas / Alta V. Paz, Guatemala / Schwartz & Barber coll. (1 male, 2 female: NMNH); 1.4.0 6, Cacao, Trece Aguas / Alta V. Paz, Guatemala / Schwartz & Barber coll. / St. ovalis Arrow / Stenotarsus ovalis Arrow dt. Stroh. (1 female: NMNH); Cabima Pan., May, 19.11, August Busck / globosus dt. Stroh. (1 male: NMNH); Cabima Pan., May, 26.11, August Busck (1 female: NMNH); Ancon, Canal Zone, Panama / June 1909 / A. H. Jennings coll. / globosus dt. Stroh. (1 male: NMNH); COSTA RICA, Prov. Puntarenas. P.N. Corcovado. Sector La Leona. Cerro Puma. 100– 300m. 17 SEP—5 OCT 2003 A. Azofeifa. Libre. L_S_267700 51887-990 #75661 / INB0003785329, INBIOCRI COSTA RICA (1 male: INBIO)

Distribution. MEXICO; GUATEMALA: Alta Verapaz; COSTA RICA: Puntarenas; PANAMA: Panama ( Fig. 265 ).

Biological Notes. Altitudinal range: 100– 300 m. Period of activity: April to October.

Remarks. See remarks on Stenotarsus orbicularis Gerstaecker.

The type material was not studied. However, specimens from MNB identified by H. F. Strohecker, by direct comparison with types, were studied. Characters like semicircular scutellum, wide elytral epipleura and teeth on male metatrochanters are not found in other species from the region, but are present in various species from southern Central America and South America (e.g., Stenotarsus subtilis Arrow and Stenotarsus obtusus Gerstaecker ), to which S. ovalis appears to be similar. This species is recorded from México for the first time, although without specific locality.

Figures

FIGURES 1 – 2. General morphology of Stenotarsus. 1) S. globosus male habitus dorsal; 2) S. ovalis male habitus ventral.

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 115 – 125. Surface of elytron of Stenotarsus spp. 115) S. cortesi; 116) S. exiguus; 117) S. globosus; 118) S. kafkai; 119) S. lemniscatus; 120) S. ovalis; 121) S. militaris; 122) S. raramuri; 123) S. rulfoi; 124) S. shockleyi; 125) S. spiropenis.

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 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 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 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).