Lutrochus vestitus (Sharp, 1882)

Maier, Crystal A. & Short, Andrew E. Z., 2013, A revision of the Lutrochidae (Coleoptera) of Venezuela, with description of six new species, Zootaxa 3637 (3), pp. 285-307 : 295-297

Lutrochus vestitus (Sharp, 1882)

( Figs. 3 , 5 , 27–33 )

Type Material. Lutrochus vestitus : Holotype: [Card mounted. Card with “Byrrhomorphus; vestitus D.S.; Type; Pancina Veia Paz.; Guatemala Champion”] “[red circle] Type ” “Panima, Guatemala; Champion” “Sharp Coll.; 1905 – 313” “B.C.A. Col. I. 2.; Byrrhomorphus; vestitus ,; Sharp” “Ƥ” (BMNH).

Other Material Examined. VENEZUELA: Falcón State: “ VENEZUELA: Falcon State/11° 10.667ʹ N, 69° 33.965ʹ W, 563 m / Cataratas del Hueque; 9.vii.2009 / leg. Shepard; mud puddles/pools / gross sample; VZ09-0709- 01Z” (2 specimens, SEMC). “ VENEZUELA: Falcon State/11° 10.667ʹ N, 69° 33.965ʹ W, 563 m / Cataratas del Hueque; 9.vii.2009 /Short & Gustafson; leaf packs/roots / at river margin; VZ09-0709-01B” (34 specimens, SEMC). Barinas State: “ VENEZUELA: Barinas State/08° 49.334ʹ N, 70° 11.993ʹ W, 203 m / nr. Santa Barbara; 15.vii.2009 /leg. Short, Gustafson, Camacho,/ Garcia & Inciarte; along river/ margins/snags; VZ09-0715-04A” (34 specimens SEMC). “ VENEZUELA: Barinas State/08° 49.334ʹ N, 70° 11.993ʹ W, 203 m /,nr. Santa Barbara; 15.vii.2009 /leg. W. Shepard/ gross sample; VZ09-0715-04Z” (18 specimens SEMC). “ VENEZUELA: Barinas State/08° 0 3.341ʹ N, 70° 56.597ʹ W, 203 m / nr. Quiri, Rio Quiu; 15.vii.2009 /leg. Shepard; river habitats/ gross sample; VZ09-0715-03Z” (1 specimen SEMC). Sucre State: “ VENEZUELA: Sucre State/10° 33.651ʹ N, 63° 10.271ʹ W, 38 m / nr. El Pilar, river by road; 30. i.2010 /leg. A. Short & M. Garcia; in flow/ kicknetting/log; VZ10- 0130-03B” (6 specimens, SEMC). “ VENEZUELA: Sucre State/10° 28.347ʹ N, 63° 33.018ʹ W, 26 m / Rio Carinicuao, S. of Cariaco/ 29. i.2010; leg. A. Short / kicknetting in flow; VZ10-0129-01A” (1 specimen, SEMC). Aragua State: “ VENEZUELA: Aragua State/ 10.48189° N, 67.60880° W, 152 m / Rio Choroni; ca. 4 km S. coast/ 6. i.2009; leg. A. Short / VZ09-0106-03A: leaf packs” (3 specimens, SEMC). “ VENEZUELA: Aragua State/ 10.39376° N, 67.79597° W, 130 m / Henri Pittier Nat. Park, Rio Cumboto/ 1.vii.2010; leg. A.E.Z. Short / kicknetting; VZ10-0701-01C” (1 specimen, SEMC). Bolívar State: “ VENEZUELA: Bolívar State/ 4° 31ʹ 19.1ʺN, 61° 31ʹ 34.0ʺW, 860 m / Gran Sabana, E. Pauji, Salto/ Catedral; 15.vii.2010 / leg. A.E.Z. Short & M. Tellez/ HGvapor lights; VZ10-0715-03C” (1 specimen SEMC). FRENCH GUIANA: “FG: Sinnemary/ 26 Nov 2007 /Queny – Road St. Elye/Sa” (7 Specimens SEMC, 2 Specimens NMHN, 5 Specimens PQC). “FG: Mana/ P. Queney – 15 Feb 04 / Road in forest of Crique/ Daranelles” (2 specimens, SEMC, 2 Specimens NMHN, 1 Specimen PQC). “FG: Seint Laurent du Maroni/ Balete ouest – crosses farm/ 30.i.2005 P. Queney/ Saint Jean” (3 specimens SEMC, 2 Specimens NMHN, 1 Specimen PQC). “FG: Sinnamary/ 26.i.2003, P. Queney/ Route Jojo” (6 specimens SEMC, 3 Specimens NMHN, 4 Specimens PQC).

Diagnosis. This species is rather distinctive, and can be distinguished from all other species of Lutrochus by its triangular apical maxillary palpomere, which bears a distinct pit-like sensilla ( Fig. 30 ). Additionally, the apical metatarsomere is entirely glabrous in L. vestitus ( Fig. 32 ); length 3.0–4.0 mm and overall body-shape is distinctively “wedge-like” ( Fig. 27 ).

Description. MALE.—Length 3.6 mm; width 2.1 mm. Body wedge-shaped and strongly convex, dark brown to black, densely pubescent; clothed with short, fine, slightly recumbent golden setae and long, erect golden setae ( Fig. 27 ).

Head broad, broadly rounded. Eye rounded, small, with short, golden interfacetal setae; eyes smooth within outline of head. Antenna short, reaching just past anterior border of pronotum, apical 9 antennomeres dark brown and clavate, clothed with short golden setae, basal antennomeres testaceous ( Fig. 30 ). Frontoclypeal suture indistinct. Clypeal margin straight, with brush of long setae apically, setae half as long as labrum. Apical margin of labrum sinuate, with short apical setal brush. Labrum clothed with sparse, golden setae. Mandibles large, dark brown, sickle-shaped; apex of mandible with three blunt teeth. Maxilla with 4-segmented palpus, apical palpomere flattened and triangular, truncate at apex ( Fig. 30 ). Labial palpus 3-segmented; apical palpomere fusiform.

Pronotum pubescent, dark brown, 2.5 times as wide as long at base, bisinuate at base. Lateral edge of pronotum with distinct bead, broadly rounded ( Fig. 27 ). Posterior margin straight anterior to scutellum. Disc of pronotum broadly convex. Scutellum triangular, as wide as long; clothed in recumbent golden setae. Hypomeron excavate posteriorly to accommodate profemur.

Elytron pubescent, dark brown to medium brown, widest at anterior fourth. Elytron broadly convex, densely punctate with very fine, shallow punctures, punctures randomly scattered, not arranged in rows; elytron clothed with dense, short, recumbent golden setae and long, erect, golden setae; humerus slightly protuberant ( Fig. 27 ). Lateral edge with distinct bead, appearing narrow in ventral aspect ( Fig. 28 ). Elytron with very weak sutural stria in apical fourth. Elytral apex acuminate.

Prosternum transverse, approximately 1.6 times as wide as long; anterior edge with strong bead, slightly deflexed to accommodate withdrawn head; prosternal process slightly wider than long, without bead laterally, obtusely angled posteriorly ( Fig. 28 ). Mesoventrite pubescent, disc fully clothed with setae. Mesepisternum and mesepimeron excavated to accommodate folded front and middle legs ( Fig. 28 ). Mesepimeron extended posteriorly to metacoxae.

Legs long and slender, dark brown to black. Profemur densely pubescent. Protibia entirely pubescent. Protarsus with basal four tarsomeres densely pubescent, lacking tufts of long golden setae ventrally; apical tarsomere as long as preceding four tarsomeres combined, pubescent dorsally and glabrous ventrally. Mesocoxa with tuft of short golden setae basally. Mesofemur densely pubescent posteriorly, becoming less so anteriorly. Mesotibia glabrous, with many scattered setae; apex with excavation laterally for reception of tarsus and notch proximal to excavation ( Fig. 31 ). Mesotarsus entirely glabrous; apical tarsomere as long as preceding four tarsomeres combined. Metatrochanter globose, with pointed projection posteriorly. Metafemur densely pubescent. Metatibia pubescent to apical 1/16, apical 1/16 glabrous. Metatarsus with basal four tarsomeres entirely pubescent; apical tarsomere glabrous, as long as previous four combined ( Fig. 32 ).

Abdomen densely pubescent, with five ventrites ( Fig. 28 ). First abdominal ventrite shallowly excavated for reception of folded hind legs. Apical ventrite broadly rounded.

Genitalia as illustrated, basal piece + parameres 1.8 mm long. Aedeagus slender and evenly curved, with slight notch at tapered tip ( Fig. 33 ). Parameres fused, pointed, with distinct lobes interiorly subapically.

Female. Length 4.2 mm; width 2.1 mm. Externally similar to male, females generally larger than males.

Intraspecific Variation. This species varies considerably in size, ranging from 3.0– 4.5 mm long and 1.6–2.2 mm wide. Additionally, specimens vary slightly in color and luster from dark brown to black, and from slightly metallic to not metallic. Some specimens examined have differing levels of setation, with patches where setae have rubbed off, as well as patches where setae have become matted down with grease.

Habitat and Distribution. This is the first record of L. vestitus , which was described from Guatemala, in South America. Specimens collected in Venezuela were compared to numerous exemplars of L. vestitus from several localities in Central America. This species is the most widely distributed in this study and ranges from the Sierra San Luis in northwestern Venezuela, along the lowland foothills of the Merida Andes, the Turimiquire mountains in the northeast, and into French Guiana and the Gran Sabana ( Fig. 5 ). A single specimen from Bolívar State was examined that likely belongs in this species, and represents a large disjunction in this widespread species’ distribution. Presumably this species occurs throughout northern South America.

Most specimens were collected in leaf packs, overhanging roots, and other emergent or submergent detritus in larger streams and small rivers. With the exception of the locality in the Gran Sabana (at 800 m), other localities ranged from the coastal lowlands up to 563 m. In Falcón State, Venezuela, specimens were collected from submerged root mats on the edge of a stream ( Fig. 3 ).

Figures

FIGURE 3. Habitat of Lutrochus species. A) L. meridaensis: Venezuela, Mérida State, Cascada Velo de la Novia; specimens were collected on the vertical wet rocks adjacent to the waterfall (collecting event VZ 09 - 0719 - 01 A). B) L. vestitus: Venezuela, Falcón State, Cataratas del Hueque; specimens were found in the exposed tree root mats along the margin (collecting event VZ 09 - 0709 - 01 B).

FIGURES 4 – 7. 4. Map of Venezuela showing collection localities of L. acuminatus (red circles) and L. cauraensis (yellow square). 5. Map of Venezuela showing collection localities of L. vestitus (red circles). 6. Map of Venezuela showing collection localities of L. meridaensis (red circles), L. minutus (orange circles), and L. maldonadoi (yellow circles). 7. Map of Venezuela showing collection localities of L. violaceus (red circles) and L. gustafsoni (yellow circles).

FIGURES 27 – 33. Lutrochus vestitus Sharp: 27. Habitus, dorsal view; 28. Habitus, ventral view; 29. Habitus, lateral view; 30. Head, ventral view, showing shape of apical maxillary palpomere; 31. Mesotibia, showing apical notch; 32. Metatarsus; 33. Aedeagus, dorsal and lateral views (scale bar = 0.62 mm).