Liocanthydrus nanops, 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 : 243-244

Liocanthydrus nanops sp. n.

Type locality. Paraguay, Paraguari Dept., Ybycui National Park.

Type material. Holotype (male): “ PARAGUAY: Paraguari Dept./Ybycui (25 km SE), in/Ybycui National Park/ 12-24 April 1980 /P. J. Spangler et al.” [printed], “ HOLOTYPE / Liocanthydrus / nanops /Baca, Gustafson, Toledo/ & Miller, 2014” [red with black line border; printed] ( USNM). Paratypes: Same data as holotype (27 males; 30 females exs. USNM); “ 29.12.33 ”, “2643”, “ PARAGUAY:/Hohenau./Alto-Parana./H. Jacob./B.M. 1954- 814.”, “ Canthydrus / octoguttatus /Zimmermann/Luis E. Grosso det./86” [label description not available] (1 female: NHM); “ BRASIL /Guarapuava/Guarauna/10- 57 / V. N. Alin” [printed except “10” (handwritten)] (1 male ex., USNM); same data except with “ Siolius / clayae /J.B.-B/Det. FN Young” [handwritten] (1 female ex., USNM; 1 female ex., FSCA); same data except no det. label, instead “FNY/Kept2/adbt2” [handwritten in pencil] (1 male ex., USNM) All paratypes labeled with: “ PARATYPE / Liocanthydrus / nanops /Baca, Gustafson, Toledo/& Miller, 2014” [blue with black line border; printed] Note: All label descriptions are included in brackets.

Diagnosis. Elytra maculate, distinguishable from other species by the following combination of characters: a) eyes small relative to head capsule, HW/EW = 1.47–1.52 ( Figs 8 , 15 ); b) posterior elytral bands strongly oblique and extending anterolaterally to basal halves of elytra ( Fig. 8 ); c) aedeagus as in Figs 21 a–e; median lobe sinuate in dorsal aspect ( Fig. 21 b); left lateral lobe broad ( Fig. 21 d), right lateral lobe with distal angle rounded and projected ( Fig. 21 e).

Liocanthydrus nanops is externally very similar to L. octoguttatus and also, though less so, to L. clayae . Externally L. nanops is distinguished from L. clayae by the smaller relative eye size and the patterning of the posterior elytral maculae, which are more obliquely oriented. Liocanthydrus nanops is distinguished from both L. clayae and L. octoguttatus by its distinct aedeagus, with a median lobe that is sinuate in dorsal aspect, similar to L. octoguttatus but not L. clayae , and is also attenuated distally to the apex in lateral aspect, similar to L. clayae , but not very elongate and subparallel like that of L. octoguttatus . The aedeagus of L. nanops also differs from both L. clayae and L. octoguttatus by its subtriangular right lateral lobe with a distinctly projected and rounded distal angle, not triangular with an acute distal angle as in L. clayae and L. octoguttatus .

Description. Measurements. TL = 2.7–3.35 mm, male max. = 3.05 mm, female max. = 3.35 mm, male min. = 2.7 mm, female min. = 2.95 mm, GW = 1.3–1.6 mm, TL/GW = 2.03–2.15, HW = 0.8–1.0 mm, EW = 0.55–0.65 mm, HW/EW = 1.47–1.52. PNWpost. = 1.25–1.4 mm, PNWant. = 0.8–0.95 mm, PNWpost./PNWant. = 1.53–1.62.

Coloration. Elytra maculate, with transverse bands; color of elytra brown; color of head pronotum and elytral maculae yellow; band pattern as in Fig. 8 , discontinuous across elytral suture, posterior elytral bands strongly oblique and extending anterolaterally onto basal half of elytra; anteromedial region of pronotal disc usually with dark maculation ( Fig. 8 ); color of venter yellowish brown to reddish brown.

Body. Body shape as in Fig. 8 , oval, moderately narrow, posteriorly attenuate; moderately convex in lateral aspect ( Fig. 15 ).

Head. Eye size small relative to head capsule, EW = 0.55–0.65 mm, HW/EW = 1.47–1.52 ( Figs 8 , 15 ).

Thorax. Elytra with lateral margins strongly ascendant medially in lateral aspect ( Fig. 15 )

Abdomen. Aedeagus as in Figs 21 a–e; median lobe sinuate in dorsal aspect ( Fig. 21 b), attenuate to apex in lateral aspect ( Figs 21 a, c); left lateral lobe broad medially; setal fringe extending nearly to median of dorsal margin, apically expanded to small field ( Fig. 21 d); right lateral lobe subtriangular, distal angle strongly projected, dorsal margin broadly emarginated along its length ( Fig. 21 e).

Etymology. The specific epithet nanops is a combination of the Greek words nanos, meaning small or dwarf, and ops, meaning eye. It is named in reference to the significantly smaller eyes bore by members of the species. It is treated as a noun in the nominative singular standing in apposition.

Biology. While there are no collection data indicating the habitat of this species, it is very likely that it is found in similar habitats to the other known species.

Distribution. Known from Paraguay and the Guarapuava region of southern Brazil ( Fig. 23)

Variation. Of the specimens examined, those from Brazil were somewhat smaller than those from Paraguay. The specimens were still observed to have a nearly identical patterning, body outline, small eyes relative to the head capsule with a HW/EW ratio that fell within the range of those from Paraguay. Examination of the aedeagus showed that the same diagnostic characters are also present, such as the median and left lateral lobes’ shape and the projecting distal angle of the right lateral lobe. Some very minor variation was seen in the shape of the distal portion of the median lobe, and overall the aedeagus was slightly smaller than those of the Paraguay specimens. Due to the limited amount of material from Brazil, geographic proximity of the two series, and lack of differentiating characters these differences were considered a part of normal variation within L. nanops . Very little variation was observed otherwise. Individuals varied slightly in overall color some individuals slightly lighter or darker than others. Maculae generally appeared as in Fig. 8 , though reduced in some individuals. The respective orientation of the bands/spots remained consistent within all observed members of this species.

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 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.

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.