Liocanthydrus angustus ( Guignot, 1957 )

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 : 235-238

Liocanthydrus angustus ( Guignot, 1957)

Canthydrus (Liocanthydrus) angustus Guignot (1957: 42) (orig. descr.); Nilsson (2005: 109) (cat.). Liocanthydrus angustus ( Guignot, 1957) ; Nilsson (2011: 27)

Type locality: Brazil, Pará State, Sierra de Cachimbo.

Type material examined. Paratype (female): “ BRASILIEN /Para/Cachimbo/ X.1955 /Pereira” [printed], “♀”, “ Paratype ” [red; printed], “Museum Paris/1960/coll. F. Guignot” [printed] (1 ex., MNHN). Holotype (male, not studied) in MZUSP. Note: All label descriptions are included in brackets.

Other material examined. Brazil: Goiás, Caldas Novas, at light, 13.iv–1.v.1993, J. Sár (1 ex., HNMB); Mato Grosso, Jacaré, PNXingu, xi.1965, MALvarenga & WCABokermann, BLT (1 ex., FSCA; 1 ex., USNM); French Guiana: Sinnamary, Piste Sante Elie, Crique Toissant, 26.xi.2007, D. Lohez leg. (1 ex., MTC).

Diagnosis. Elytra without maculation, distinguished from other immaculate members by the following combination of characters: a) large eye size, EW/HW = 1.63–1.73 ( Fig. 3 ); b) body outline as in Fig. 3 , slender and gradually attenuate posteriorly; c) aedeagus as in Figs 16 a–e, with left lateral lobe slender, distinctly subequal in length to median lobe ( Fig. 16 d).

Externally L. angustus appears very similar to L. uniformis . However, L. angustus has a larger relative eye size, EW/HW = 1.63–1.73 (fig. 3), a body outline that is less rounded and posteriorly more attenuate ( Fig. 3 ), and has an aedeagus with a distinctly longer and more slender left lateral lobe.

Description. Measurements. TL = 2.9–3.05 mm, male max. = 3.0 mm, female max. = 3.05 mm, male min. = 2.9 mm, GW = 1.4–1.45 mm, L/GW = 2.07–2.18, HW = 0.8–0.9 mm, EW = 0.5–0.55 mm, HW/EW = 1.63–1.73, PNWpost = 1.3–1.4 mm, PNWant = 0.85–0.9 mm, PNWpost/PNWant = 1.51–1.55.

Coloration. Elytra without maculation; color of elytra brown to reddish brown; color of head and pronotum yellowish red to reddish brown, slightly lighter in color than elytra ( Fig. 3 ); color of venter reddish brown, similar in color to head.

Body. Body outline as in Fig. 3 ; oval, narrow, attenuate posteriorly to apex; narrow, weakly convex in lateral aspect ( Fig. 10 ).

Head. Eyes large relative to head capsule, HW/EW = 1.63–1.73 ( Figs 3 , 10 ).

Thorax. Elytra with lateral margins slightly ascendant medially in lateral aspect ( Fig. 10 ).

Abdomen. Aedeagus as in Figs 16 a–e; median lobe narrow and attenuate ( Figs 16 a–c); left lateral lobe narrow, subequal in length to median lobe, with setal fringe limited to distal third ( Fig. 16 d); right lateral lobe triangular, distal angle acute, not projected ( Fig. 16 e).

Variation. The variation exhibited by this species was difficult to assess due to the limited number of specimens examined for this study. The examined individuals differed slightly in overall color, with some specimens slightly darker and more reddish brown than others. There was also some very slight variation in the overall size of the specimens.

Biology. Available collecting data were very limited for this species. One specimen was labeled as taken from a light and another named a creek as the collection site.

Distribution. Known from French Guiana and Brazil ( 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.