Lutrochus leeanneae, Maier, Crystal A. & Short, Andrew Edward Z., 2014

Maier, Crystal A. & Short, Andrew Edward Z., 2014, Review of the Lutrochidae (Coleoptera) of the Guianas and Lesser Antilles, with description of four new species, Zootaxa 3895 (1) : -

Lutrochus leeanneae n. sp.

( Figs. 2 , 12–17 )

Type material. Holotype: “ SURINAME: Sipaliwini/ 2° 58' 38.316"N, 55° 23' 5.9928"W, 200 m / Camp 4 (low): Kasikasima/ 24-iii-2012 / leg. Short; UV light trap; SR12-0322-LT4” Holotype deposited in NZCS. Paratypes (5). SURINAME: Sipaliwini: “ SURINAME: Sipaliwini/ 2° 58' 38.316"N, 55° 23' 5.9928"W, 200 m / Camp 4 (low): Kasikasima/ 24-iii-2012 / leg. Short; UV light trap; SR12-0322-LT4” (5 specimens, SEMC).

Diagnosis. This species is most similar to L. gustafsoni and L. cauraensis , two species which occur in southern Venezuela. These share the characters of the lateral margin of the mesotibia greatly expanded, with two distinct longitudinal carinae; and the metatarsi of all three species are completely glabrous. Lutrochus leeanneae can be distinguished from these two species by the presence of a dense patch of long golden setae apically on the protibia of the male ( Fig. 16); and protarsi glabrous ventrally, pubescent nearly to apex dorsally ( Fig. 16).

Diagnosis. MALE. – Length 4.5 mm; width 2.5 mm. Body slightly wedge-shaped and strongly convex, dark brown to black, densely pubescent; clothed with short, fine, recumbent, dark bronze setae ( Fig. 12 ).

Head broad, broadly rounded, very 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 I – III testaceous below, brunneous above, antennoeres IV – XI brunneous; antennomeres short and clavate, nearly serrate, clothed with short golden setae. Frontoclypeal suture indistinct. Clypeal margin straight. Apical margin of labrum broadly rounded, with golden apical setal brush, lateral setae twice as long as medial setae. Labrum clothed with sparse and short golden setae. Mandibles large, dark brown, sickle-shaped; apex of mandible with 2 distinct teeth. Maxilla with 4-segmented palpus, apical palpomere flattened and rounded-triangular; Labial palpus 3-segmented; apical palpomere cylindrical.

Pronotum pubescent, dark brown, 2.0 times as wide as long at base, bisinuate at base ( Fig. 12 ). Lateral edge of pronotum with distinct bead, borders not explanate. Posterior margin straight anterior to scutellum. Disc broadly convex. Scutellum triangular, as wide as long; clothed in recumbent golden setae. Hypomeron excavate posteriorly to accommodate profemur.

Elytron pubescent, clothed with dense, short, recumbent dark bronze setae, medium brown, widest at anterior third. Elytron strongly convex, densely punctate, with very fine, shallow punctures, punctures randomly scattered, not arranged in rows; humerus protuberant ( Fig. 12 ). Lateral edge with distinct and weakly sinuate bead ( Fig. 14 ). Elytron lacking faint sutural stria in apical third. Elytral apex rounded and slightly 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, with bead laterally, acute posteriorly ( Fig. 13 ). Disc smooth, lacking carinae to accommodate profemora laterally. Metaventrite pubescent, disc fully clothed with setae, with distinct marginal carinae laterally. Mesepisternum and epipleuron excavated to accommodate folded front and middle legs. Epipleuron not explanate, narrowing posteriorly to metacoxae.

Legs long and slender, dark brown. Procoxae transverse. Profemur densely pubescent, medium brown, strongly excavate ventrally to receive protibia. Protibia entirely pubescent, with dense patch of long golden setae apically, excavate dorsally to receive protarsus, explanate laterally. Protarsus with basal four tarsomeres densely pubescent, lacking tufts of long golden setae ventrally; apical tarsomere 1.25 times as long as preceding four tarsomeres combined, glabrous ventrally, pubescent nearly to apex dorsally ( Fig. 16). Mesocoxa with tuft of short golden setae basally. Mesofemur with nearly parallel sides; densely pubescent posteriorly, becoming less so anteriorly, reddish-brown dorsally, medium brown ventrally. Mesotibia completely glabrous, with few scattered setae, lacking small patch of short golden setae at apex; lateral margin greatly expanded, with two distinct longitudinal carinae; apex with excavation laterally for reception of mesotarsus. Mesotarsus with all tarsomeres entirely glabrous; apical tarsomere 1.25 times as long as preceding four tarsomeres combined. Metacoxa with two weak posterior projections. Metatrochanter globose, excavate posteriorly. Metafemur densely pubescent. Metatibia entirely pubescent, except for a narrow, longitudinal glabrous band dorsally; with short, golden setae; apex glabrous, lacking fringe of setae. Metatarsus with basal four tarsomeres entirely pubescent; apical tarsomere pubescent only at base, as in Fig 16, 1.25 times as long as previous four combined.

Abdomen densely pubescent, with five ventrites ( Fig. 13 ). First abdominal ventrite shallowly excavate for reception of folded hind legs, excavation only reaching halfway to posterior edge of ventrite. Apical ventrite broadly rounded.

Genitalia as illustrated, basal piece + parameres 2.4 mm long. Aedeagus very slender and only slightly curved. Parameres fused, pointed, with short distinct lobes interiorly subapically, lobes not extended at apex ( Fig. 15 ).

Female. Length 4.7 mm; width 2.6 mm. Externally similar to male, females generally larger than males.

Intraspecific Variation. This species varies slightly in size, ranging from 4.5–4.7 mm long and 2.5–2.6 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. leeanneae , is named in honor of intrepid conservation biologist Dr. Leeanne Alonso, who led the expedition to Suriname on which this beetle was collected, as well as many others that have documented the biodiversity of the Guiana Shield.

Habitat and Distribution. This species is only known from the type locality at Kasikasima, Sipaliwini District, Suriname ( Fig. 2 ). All specimens were collected in a UV light trap, so the exact habitat is unknown. The light was situated in a densely forested area less than 25 meters from the Palumeu River. Numerous other small creeks and forest pools were within 500 meters of the site. However, the biology is likely to be similar to other species from the region—they inhabit leaf packs and waterlogged woody debris in streams and rivers.

Figures

FIGURES 1 – 2. 1. Map of northeastern South America showing collection localities of L. funkae, L. leeanneae, L. grenadensis, and L. wao. 2. Habitat of L. wao, collected in partially submerged leafpacks that were caught behind a fallen branch in a flowing forested stream.

FIGURES 12 – 15. Lutrochus leeanneae n. sp.: 12. Habitus, dorsal view; 13. Habitus, ventral view; 14. Habitus, lateral view; 15. Aedeagus, dorsal and lateral views (scale bar = 1.0 mm).