Revision of the Neotropical burrowing water beetle genus Liocanthydrus Guignot (Coleoptera: Noteridae: Noterinae: Noterini) with the description of two new species Author Baca, Stephen M. Author Gustafson, Grey T. Author Toledo, Mario Author Miller, Kelly B. text Zootaxa 2014 3793 2 231 246 journal article 45928 10.11646/zootaxa.3793.2.3 cec96d21-19fa-4e66-8305-9e70166f04f7 1175-5326 230581 5E6DB00C-E98F-4D9D-958B-95B634E6D9E4 Liocanthydrus uniformis ( Zimmermann, 1921 ) Canthydrus uniformis Zimmermann (1921: 189) (orig. descr.); Blackwelder (1944: 73) . Liocanthydrus uniformis (Zimmermann) ; Nilsson (2011:28) (cat.). Canthydrus ( Liocanthydrus ) uniformis (Zimmermann) ; Guignot (1957: 43) ; Nilsson (2005: 110) (cat.). Siolius amazonicus J. Balfour-Browne (1969: 6) Nilsson (2005: 124) (cat.); Nilsson (2011: 31) (cat.). ( new synonymy ). Type localities . Liocanthydrus uniformis : Brazil , Mato Grosso do Sul State, Corumbá; L. amazonicus : Brazil , Amazonas State, Campo do Ariramba. Type material examined. Canthydrus uniformis , Holotype (female): “ BRASILIEN ” [printed], “Matto Grosso/Corumba” [printed], “ Type ” [small round label, handwriting A. Zimmermann], “Samml. A. Zimmermann” [printed], “ Holotypus / Canthydrus / uniformis Zimm. /1921/ Staatssamml. München” [red, unauthorized curatorial label; handwritten except “ Holotypus ” and “Staatssamml. München” (printed)] ( ZSM ). Siolius amazonicus , Holotype (male): “♂”, “ Type ” [circular, red bordered NHM label; printed], “ BRAZIL : Amazonas/Campo do Ariramba/Ig. Quebra-dente/ 29.iv.1948 . H.Sioli” [printed], “Em agua ±/parada” [handwritten], “ Siolius / amazonicus type /J. Balfour-Browne det./1967” [handwritten except “J. Balfour-Browne det./196” (printed)] ( NHM ); Paratype (female): “♀” [printed], “Para-/ type ” [circular, yellow bordered NHM label; printed], “ BRAZIL : Amazonas/Campo do Ariramba/Ig. Quebra-dente/ 29.iv.1948 . H. Sioli” [printed], “ Siolius / amazonicus P’type./J. Balfour-Browne det./1967” [handwritten except “J. Balfour-Browne det./196” (printed)] (1 ex., NHM ); Paratype (female): “ BRAZIL : Amazonas/Igarapé Irurá./ 25.vi.1947 . H. Sioli” [printed], “ Siolius / amazonicus P’type./J. Balfour-Browne det./1967” [handwritten except “J. Balfour-Browne det./196” (printed)] (1 ex., FSCA ). Note: All label descriptions are included in brackets. Diagnosis. Elytra without maculation, distinguishable from other similar species by the following combination of characters: a) smaller relative eye size, HW/EW = 1.55–1.63 ( Figs 4 , 11 ); b) body outline as in Fig. 4 , stout, moderately attenuate posteriorly ( Fig. 4 ); c) aedeagus as in Figs 17 a–e, with left lateral lobe distinctly short ( Fig. 17 d). Externally L. uniformis appears very similar to L. angustus . Liocanthydrus uniformis bears a larger relative eye size, HW/EW = 1.55–1.63 ( Figs 4 , 11 ), a more rounded and less attenuate body shape and a shorter and rounded left lateral lobe of the aedeagus. Description. Measurements. TL = 2.85–2.95 mm , GW = 1.4–1.45 mm , L/GW = 2.00–2.11, HW = 0.85–0.9 mm , EW = 0.5–0.6 mm , HW/EW = 1.55–1.63, PNWpost. = 1.35 mm . PNWant. = 0.85–0.9 mm , PNWpost/ PNWant = 1.53–1.55. Coloration. Elytra without maculation; color of elytra brown; color of head and pronotum yellowish brown, lighter than elytra in color ( Fig. 4 ); color of venter reddish brown. Body. Body outline as in Fig. 4 ; oval, stout, lateral margins rounded, attenuate posteriorly; moderately convex in lateral aspect ( Fig. 11 ). Head. Eye size small relative to head capsule, HW/EW = 1.55–1.63 ( Figs 4 , 11 ). Thorax . Elytra with lateral margins slightly ascendant medially ( Fig. 11 ). Abdomen. Aedeagus as in Figs 17 a–e; median lobe narrow and attenuate ( Figs 17 a–c); left lateral lobe short, ca. 2/3 × median lobe length, ventral margin round ( Fig. 17 d); right lateral lobe triangular, distal angle acute and not projected ( Fig. 17 e). Variation. The variation exhibited by this species was difficult to assess due to the limited number of specimens examined in this study. Those examined showed very little variation with only very slight differences in shade of color and in size. Biology. Collecting data were not available for the material examined of this species. Distribution. Brazil ; known from Amazonas and Mato Grosso do Sul ( Fig. 23 ).