Liocanthydrus armulatus, Baca, Stephen M., Gustafson, Grey T., Toledo, Mario & Miller, Kelly B., 2014

Baca, Stephen M., Gustafson, Grey T., Toledo, Mario & Miller, Kelly B., 2014, Revision of the Neotropical burrowing water beetle genus Liocanthydrus Guignot (Coleoptera: Noteridae: Noterinae: Noterini) with the description of two new species, Zootaxa 3793 (2), pp. 231-246 : 240-241

Liocanthydrus armulatus sp. n.

Type locality. Venezuela, Bolivar State, Road to Pauji.

Type material examined. Holotype (male): “ VENEZUELA: Bolivar State/ 4°36'51.2"N, 61°23'30.2"W /Road to Pauji; 3.viii.2008 / 895 m, leg. A. Short/AS-08-070; Stream margin” [printed], “(barcode) SM0828443 KUNHM- ENT ” [printed], “ HOLOTYPE / Liocanthydrus / armulatus /Baca, Gustafson, Toledo & Miller, 2014” [red with black line border; printed] ( MIZA). Paratypes (males): Same data as Holotype except “SM0828445 KUNHM-ENT” and “SM0828448 KUNHM-ENT” (2: SEMC). Paratypes (females): Same data as Holotype except “SM0828446 KUNHM-ENT” and “SM0828447 KUNHM-ENT” (2: SEMC). Notes: All paratypes labeled with: “ PARATYPE / Liocanthydrus / armulatus /Baca, Gustafson, Toledo & Miller, 2014” [blue with black line border; printed]. All label descriptions are included in brackets.

Diagnosis. Elytra maculate. Distinguishable from other maculate species by the following combination of characters: a) robust, humeral region very broad, TL/GW = 2.00–2.03, PNWpost./PNWant. = 1.64–1.68 ( Fig. 6 ); b) yellow bands on elytra broad, not reduced to spots, and all extending perpendicular to elytral suture ( Fig. 6 ); c) aedeagus as in Figs 19 a–e, with distal region of median lobe curved dorsally, moderately elongate and subparallel in lateral aspect, ( Figs 19 a, c); left lateral lobe with setal fringe extended basally to ca. median of overall length along dorsal margin( Fig. 19 d); right lateral lobe subtriangular, distal angle projected and rounded ( Fig. 19 e).

Externally L. armulatus n. sp. appears very similar to L. bicolor , but is noticeably more robust. Liocanthydrus armulatus is also distinguished by its distinct aedeagus, with a median lobe that, in lateral aspect, is distally more elongate and subparallel, not blunt. The aedeagus of L. armulatus also differs by its subtriangular right lateral lobe, with a distinctly projected and rounded distal angle, not triangular with the distal angle acute.

Description. Measurements. TL = 3.1–3.15 mm, GW = 1.5–1.55 mm, TL/GW = 2.00–2.03, HW = 0.9–0.95 mm, EW = 0.55–0.6 mm, HW/EW = 1.58–1.64, PNWant. = 0.9–0.95 mm, PNWpost. = 1.5–1.55 mm, PNWpost./ PNWant. = 1.64–1.68.

Coloration. Elytra maculate, with transverse bands; color of elytra brown to dark brown; color of head, pronotum and elytral bands ranging from yellow to brownish yellow; all examined specimens with small darkened maculation situated on anteromedial region of pronotum; elytral bands as in Fig. 6 , broad, not obliquely oriented, and discontinuous across elytral suture; color of venter yellowish brown to reddish brown.

Body. Body outline as in Fig. 6 ; oval, robust, very broad, attenuate posteriorly; moderately convex in lateral aspect ( Fig. 13 ).

Head. Eye size relative to head capsule: HW/EW = 1.58–1.64.

Thorax. Elytra with margins moderately ascendant medially in lateral aspect ( Fig. 13 ).

Abdomen. Aedeagus as in Figs 19 a–e; distal portion of median lobe subparallel in lateral aspect ( Figs 19 a, c) and rounding at apex, lateral margins sinuate ( Fig. 19 b), ventral groove nearly extending to apex ( Fig. 19 c); left lateral lobe weakly curved; setal fringe extending ca. to, or just short of, median of inner dorsal margin ( Fig. 19 d); right lateral lobe subtriangular, distal angle strongly projected and dorsal margin broadly emarginated along its length ( Fig. 19 e).

Variation. The variation exhibited by this species was difficult to assess due to the limited number of specimens available for examination. One specimen appeared to be teneral and was relatively pale in overall coloration. All other specimens were otherwise nearly identical, including the type, with some very slightly darker or lighter in color.

Etymology. The specific epithet armulatus is a combination of the Latin words armus, meaning shoulder and latus, meaning broad, in reference to the species’ broad humeral region. It is treated as an adjective in the nominative singular.

Biology. All five specimens of this species were taken from a single collection event at a stream margin.

Distribution. Known from the type locality in the extreme southeast region of Bolivar State, Venezuela ( Fig. 23).

Figures

FIGURES 3 – 9. Liocanthydrus species, dorsal habitus: 3) L. angustus; 4) L. uniformis; 5) L. bicolor; 6) L. armulatus sp. n.; 7) L. clayae; 8) L. nanops sp. n.; 9) L. octoguttatus (illustration). Scale bar = 1.0 mm.

FIGURES 16 – 22. Aedeagi of Liocanthydrus species. a) median lobe, right lateral aspect; b) median lobe, dorsal aspect; c) median lobe, left lateral aspect; d) left lateral lobe, right lateral aspect; e) right lateral lobe, left lateral aspect: 16) L. angustus; 17) L. uniformis; 18) L. bicolor; 19) L. armulatus sp. n.; 20) L. clayae; 21) L. nanops sp. n.; 22) L. octoguttatus. Scale bars = 0.2 mm. Notes: Terminology follows K. B. Miller & Nilsson (2003). Illustrations of lateral lobes depict medial (inner) surfaces.

FIGURES 10 – 15. Liocanthydrus species, lateral aspect: 10) L. angustus; 11) L. uniformis; 12) L. bicolor; 13) L. armulatus sp. n.; 14) L. clayae; 15) L. nanops sp. n. Scale bar = 1.0 mm.