Lutrochus cauraensis, Maier, Crystal A. & Short, Andrew E. Z., 2013

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 : 289-290

Lutrochus cauraensis n. sp.

( Figs. 4 , 14–17 )

Type Material. Holotype male: “ Venezuela – BO [Bolívar State]/Kanarakuni/ Alto Caura 450m ” “10.-13.9 1964/ F.F. Yepez / J. Bechyne lgt.” Holotype deposited in MIZA. Paratypes (6): VENEZUELA: Bolívar State: Same locality data as holotype. Paratypes will be deposited in: 3 in MIZA, 2 in SEMC, and 1 in USNM.

Diagnosis. This species can be distinguished from all other Lutrochus species by the following combination of characters: large size (~ 4.5 mm), the mesotibia with apical excavation for protarsus, elytra not explanate, prosternum not deflexed in anterior half, apical protarsomere with a discrete pubescent patch in the basal third, with apical two-thirds glabrous ( Fig. 18 ) and body without metallic sheen dorsally ( Fig. 14 ).

Description. MALE.—Length 4.5 mm; width 2.2 mm. Body wedge-shaped and strongly convex, dark brown to black, densely pubescent; clothed with short, fine, recumbent golden setae ( Fig. 14 ).

Head broad, broadly rounded, weakly grooved beneath eye for reception of antenna. Eye rounded, small, with short, golden interfacetal setae; eyes smooth within outline of head. Antenna short, reaching slightly past anterior border of pronotum, antennomeres short, dark brown and clavate, clothed with short golden setae. Frontoclypeal suture indistinct. Clypeal margin straight. Apical margin of labrum straight, with apical setal brush, lateral setae twice as long as medial setae. Labrum clothed with sparse golden setae. Mandibles large, dark brown, sickleshaped; apex of mandible blunt, lacking distinct teeth. Maxilla with 4-segmented palpus, apical palpomere flattened and triangular, truncate at apex; Labial palpus 3-segmented; apical palpomere cylindrical.

Pronotum pubescent, dark brown, 1.6 times as wide as long at base, bisinuate at base ( Fig. 14 ). Lateral edge of pronotum with distinct bead, slightly explanate apically. 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 third. 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; humerus not protuberant ( Fig. 14 ). Lateral edge with distinct and weakly sinuate bead ( Fig. 16 ). Elytron wih faint sutural stria in apical third. Elytral apex strongly acuminate.

Prosternum transverse, approximately two times as wide as long; anterior edge with weak bead, slightly deflexed to accommodate withdrawn head; prosternal process about as wide as long, without bead laterally, rounded posteriorly ( Fig. 15 ). Mesoventrite pubescent, disc fully clothed with setae. Mesepisternum and mesepimeron excavated to accommodate folded front and middle legs. Mesepimeron extended posteriorly to metacoxae.

Legs long and slender, reddish-brown. 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, glabrous at base, pubsecent in apical 2/3 ( Fig. 18 ). Mesocoxa with tuft of short golden setae basally. Mesofemur densely pubescent posteriorly, becoming less so anteriorly. Mesotibia completely glabrous, with few scattered setae, lacking small patch of short golden setae at apex; apex with excavation laterally for reception of tarsus. Mesotarsus with all tarsomeres entirely glabrous; apical tarsomere 1.5 times as long as preceding four tarsomeres combined. Metatrochanter globose. Metafemur densely pubescent. Metatibia entirely pubescent, with short, golden setae. Metatarsus with basal four tarsomeres entirely pubescent; apical tarsomere glabrous, as long as previous four combined ( Fig. 19 ).

Abdomen densely pubescent, with five ventrites ( Fig. 15 ). First abdominal ventrite shallowly excavated for reception of folded hind legs. Apical ventrite broadly rounded.

enitalia as illustrated, basal piece + parameres 2.4 mm long. Aedeagus slender and curved, becoming more curved at tapered tip. Parameres fused, pointed, with short distinct lobes interiorly subapically ( Fig. 17 ).

Female. Length 4.5 mm; width 2.6 mm. Externally similar to male, females generally larger than males.

Intraspecific Variation. This species varies considerably in size, ranging from 4.5–5.0 mm long and 2.6–2.8 mm wide. Additionally, specimens vary slightly in color from dark brown to black. We have also noted that specimens in the series 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.

Etymology. This species is named “ cauraensis ” after the type locality at Alto Caura, Bolívar State, Venezuela.

Habitat and Distribution. Specimens of this species are only known from a single collecting event at the type locality in Bolívar State ( Fig. 4 ). They were collected in Alto Caura at an elevation of 450m. The habits and microhabitat preferences of this species are unknown.

Figures

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 14 – 19. Lutrochus cauraensis n. sp.: 14. Habitus, dorsal view; 15. Habitus, ventral view; 16. Habitus, lateral view; 17. Aedeagus, dorsal and lateral views (scale bar = 0.62 mm); 18. Protarsus; 19. Metatarsus.