Lutrochus meridaensis, 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 : 299-301

Lutrochus meridaensis n. sp.

( Figs. 3 , 6 , 40–47 )

Type Material. Holotype male: “ VENEZUELA:Merida State/8° 52.423ʹ N, 71° 37.611ʹ W, 1616 m / Cascada velo de la Novia/ 19.vii.2009; leg. Short, Gustafson/ Camacho, Garcia, & Inciarte/ VZ09-0719-01A; wet rocks/seeps” “SEMC0881687/KUNHM-ENT”. Holotype deposited in MIZA. Paratypes (13): VENEZUELA: Mérida State: Same locality data as holotype. Paratypes will be deposited in: 2 in MIZA, 1 in MALUZ, 1 in NMW, 7 in SEMC (1 on SEM stub), and 2 in USNM.

Diagnosis. This species can be distinguished from all other described Lutrochidae by the unique diamondshaped scutellum, the medial circular glabrous patch on the metasternum, and the presence of seven shallow rows of punctures on the elytron.

Description. MALE.—Length 2.6 mm; width 1.4 mm. Body wedge-shaped and strongly convex, dark brown to black, densely pubescent; clothed with short, fine, slightly recumbent golden hairs ( Fig. 40 ).

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 ( Fig. 43 ). Antenna short, reaching slightly past anterior border of pronotum, apical 9 antennomeres short, dark brown and clavate, clothed with short golden setae ( Fig. 43 ). Frontoclypeal suture indistinct. Clypeal margin straight, with brush of long setae apically, setae nearly as long as labrum. Apical margin of labrum sinuate, apical setal brush, lateral setae three times as long as medial setae. Labrum clothed with sparse, blunt setae. Mandibles large, dark brown, sickle-shaped; apex of mandible with one or two blunt teeth, if with two teeth, weakly so; prostheca with apical field of papilliform sensillae. Maxilla with 4-segmented palpus, apical palpomere flattened and triangular, truncate at apex ( Fig. 43 ); galea with dense apical brush of setae, lateral setae two times as long as medial setae; lacinia shorter and smaller than galea or palpus, with dense brush of curved setae on inner margin. Labial palpus 3-segmented; apical palpomere fusiform. Pronotum pubescent, dark brown, two times as wide as long at base, bisinuate at base ( Fig. 40 ). Lateral edge of pronotum with distinct bead, slightly explanate apically ( Fig. 42 ). Posterior margin notched medially to receive pointed anterior margin of scutellum. Disc of pronotum broadly convex. Scutellum diamond-shaped, about as wide as long ( Fig. 46 ). Hypomeron excavate posteriorly to accommodate femur ( Fig. 42 ).

Elytron pubescent, dark brown, with slight metallic sheen, widest at base ( Fig. 40 ). Elytron broadly convex, with seven rows of widely spaced coarse punctures (3 times diameter of punctures); intervals with dense setae; humerus not protuberant ( Fig. 40 ). Lateral edge with distinct bead; epipleuron appearing narrow in ventral aspect ( Fig. 41 ). Elytral apex slightly acuminate.

Prosternum transverse, approximately two times as wide as long; anterior edge with strong bead, slightly deflexed to accommodate withdrawn head; prosternal process about as wide as long, with bead laterally, acuminate posteriorly ( Fig. 41 ). Mesoventrite pubescent, with distinct, round glabrous patch medially ( Fig. 45 ). Mesepisternum and mesepimeron excavated to accommodate folded front and middle legs. Mesepimeron extended posteriorly nearly to metacoxae.

Legs long and slender. Profemur densely pubescent. Protibia pubescent to apical 1/9th. Protarsus with all tarsomeres glabrous, except for tufts of golden setae ventrally on all tarsomeres; apical tarsomere 1.5 times as long as preceding four tarsomeres combined. Mesocoxa with tuft of long golden setae basally. Mesofemur densely pubescent posteriorly, becoming less so anteriorly. Mesotibia completely glabrous, with small patch of golden setae at apex; apex without excavation laterally for reception of tarsus ( Fig. 44 ). Mesotarsus with all tarsomeres glabrous, except for tufts of golden setae ventrally on all tarsomeres, with single long seta (twice as long as preceding tarsomere) arising from fourth tarsomere; apical tarsomere as long as preceding four tarsomeres combined. Metatrochanter globose, without posterior extensions. Metafemur densely pubescent. Metatibia entirely glabrous, with small patch of golden setae at apex. Metatarsus glabrous, with apical tarsomere as long as previous four combined.

Abdomen densely pubescent, with five ventrites ( Fig. 41 ). First ventrite shallowly excavated for reception of folded hind legs. Apical ventrite broadly rounded.

Genitalia as illustrated, basal piece + parameres 1.6 mm long. Aedeagus slender and curved, becoming more curved at tapered tip ( Fig. 47 ). Parameres fused, pointed, with distinct lobes interiorly subapically.

Female. Length 3.2 mm; width 1.4 mm. Externally similar to male, females generally larger than males.

Intraspecific Variation. This species varies considerably in size, ranging from 2.5–3.2 mm long and 1.4–1.7 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.

Etymology. This species, L. meridaensis , is named for the type locality in Mérida State, Venezuela.

Habitat and Distribution. This species is known only from the type locality, the Cascada Velo de la Novia in Mérida State, Venezuela ( Fig. 6 ). The type series was collected among liverworts on the seepages and spray zone adjacent to a waterfall ( Fig. 3 ). This is the first known record of the family from hygropetric habitats. A second visit to this locality and other similar nearby habitats during the dry season (January) in 2012 did not yield additional specimens.

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 40 – 47. Lutrochus meridaensis n. sp.: 40. Habitus, dorsal view; 41. Habitus, ventral view; 42. Habitus, lateral view; 43. Head, three-quarters view, showing shape of apical maxillary palpomere; 44. Mesotibia; 45. SEM of metasternum, showing medial bare patch; 46. SEM of scutellum; 47. Aedeagus, lateral view (scale bar = 0.62 mm).