Liocanthydrus bicolor ( J. Balfour-Browne, 1969 ) J. Balfour-Browne, 1969

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 : 239-240

Liocanthydrus bicolor ( J. Balfour-Browne, 1969) n. comb.

Siolius bicolor J. Balfour-Browne (1969: 5) (orig. descr.); Nilsson (2005: 124) (cat.); Nilsson (2011: 31) (cat.).

Type locality. Brazil, Amazonas State, Tomé-Assu.

Type material examined. Holotype (male): “ BRAZIL:/Amazonas, Tome [sic!]-assu/ 9.xi.1946 /H. Sioli”, “ 9.11.1946 Tomé-assú/Fonte na floresta/na sahida da fonte” [handwritten; folded paper], “ Siolius / bicolor Type /J. Balfour-Browne det. 1967”, “ Type [circular, red bordered NHM label; printed]” ( NHM). Paratypes “ BRAZIL./ Porto Velho/iix-ix.1937/H.E. Hinton.” [printed], “ Siolius / bicolor P’type!/J. Balfour-Browne det. 1967” [handwritten except for “J. Balfour-Browne det./196” (printed)] (1 female ex., NHM; 2 males and 2 females exs. FSCA). Note: All label descriptions are included in brackets.

Other material examined. Brazil: Aldeia, Yavaruhu-Igarape, Gurupi-Uma, Maranhae, 45 km E. of Caninde, Rio Gurupi (Para), in stream, 9–12.xii.1964, #13, B.Malkin (1 ex., USNM); Para: Rio Xingu Camp, 52°22'W, 3°39'S, Altamira (ca. 60 km S.), 3.vii.1986, leg. P. Spangler & O. Flint (1 ex., USNM). Suriname: Saramacca District, 05°20'N, 55°26'W, Coesewinjneproject, trib. Of Costerikreek, 19.iii.1970, leg. N. Nieser (SN 356) (3 exs., NHMW); Sipaliwini District, 2°10.521'N, 56°47.244'W, 228 m, Camp 1, on Kutari River, leg. Short & Kadosoe, forest stream, 19.viii.2010, SR10-0819-02A 2010 CI-RAP Survey (3 exs., SEMC); same data except 20.viii.2010, SR10-0820-01A (37 exs., SEMC); 2°21.776'N, 56° 41.861W, 237 m, Camp 3, Wehepai, leg. Short & Kadosoe, sandy forest creek, 4–6.ix.2010, SR10-0904-01A 2010 CI-RAP Survey (14 exs., NZCS, SEMC).

Diagnosis. Elytra maculate. Distinguished from other members of Liocanthydrus by the following combination of characters: a) humeral region broad ( Fig. 5 ), L/GW = 1.93–2.07, PNWpost/PNWant = 1.64–1.65; b) patterning as in Fig. 5 , with bands of elytra broad and extending perpendicular to elytral suture; c) aedeagus as in Figs 18 a–e, with median lobe blunt and abruptly attenuate to apex in lateral perspective ( Figs 18 a, c); right lateral lobe triangular with distal angle acute, not projected ( Fig. 18 e).

Externally L. bicolor appears extremely similar to L. armulatus but is noticeably less robust. Liocanthydrus bicolor is also distinguished by its distinct aedeagus, with a median lobe that is distally blunt and not elongate in lateral aspect, and also a right lateral lobe that is triangular with the distal angle acute, not projected.

Description. Measurements. TL = 2.75–3.25 mm, male max. = 3.0 mm, female max. = 3.25 mm, male min. = 2.75 mm, female min. = 2.85 mm. GW = 1.45–1.6 mm, L/GW = 1.93–2.07, HW= 0.85–0.95 mm, EW= 0.55–0.6 mm, HW/EW= 1.57–1.60, PNWpost = 1.4–1.55 mm, PNWant = 0.85–0.95 mm, PNWpost/PNWant = 1.64–1.65.

Coloration. Elytra maculate, with transverse bands; color of elytra brown to very dark brown, sometimes nearly black, or reddish brown; color of head, pronotum and elytral maculae ranging from yellow or brownish yellow to reddish brown; some individuals with small dark maculation on anteromedial region of pronotum, posteriad to head capsule; elytral bands as in Fig. 5 , broad, not obliquely oriented, and discontinuous across elytral suture, many individuals with small maculae at elytral apex; color of venter yellowish brown to darker reddish brown.

Body. Body outline as in Fig. 5 ; oval, broad, attenuate posteriorly; slightly convex in lateral aspect ( Fig. 12 ).

Head. Eye size relative to head capsule: HW/EW = 1.57–1.60.

Thorax. Elytra with lateral margins slightly ascendant medially in lateral aspect ( Fig. 12 ).

Abdomen. Aedeagus as in Figs 18 a–e; median lobe weakly sinuate in dorsal aspect ( Fig. 18 b), distally blunt, distoventral margin obliquely rounded to apex in lateral aspect ( Figs 18 a, c); left lateral lobe slightly curved and narrowed from base, setal fringe restricted to distal third ( Fig. 18 d); right lateral lobe triangular, distal angle acute and not projected ( Fig. 18 e).

Biology. Liocanthydrus bicolor can be found in streams and creeks. The majority of the specimens were taken from a single collection event at a “sandy forest creek”.

Distribution. Occurs in northern to central areas of South America. Specimens examined were collected from the Sipaliwini District, Suriname and Mato Grosso, Brazil.

Variation. Specimens from Suriname exhibit lighter coloration than those from Brazil. Although darker, the maculate patterning of Brazilian specimens was still distinctly present and shared a color with that of the head and pronotum, but was less contrasted with the darkened base color of the elytra. Some minor differences in overall size were also observed, but do not appear to be correlated with locality.

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.