Liocanthydrus Guignot

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 : 245-246

Key to the species of Liocanthydrus Guignot

1 Elytra immaculate, evenly colored ( Figs 3, 4 )................................................................ 2

- Elytra with maculation of yellow to reddish brown bands or spots ( Figs 5–9 )...................................... 3

2 Robust in (L/GW = 2.00–2.11) ( Fig. 4 ); distance between eyes greater than 2/3 × greatest head width (HW/EW = 1.55–1.63) ( Figs 4 , 11 ); aedeagus as in Figs 17 a–e, with left lateral lobe short, approximately 2/3 × length of median lobe ( Fig. 17 d).............................................................................................. L. uniformis

- Slender and oval in (L/GW= 2.07–2.18) ( Fig. 3 ); distance between eyes less than 2/3 × greatest head width (EW/HW = 1.63–1.73) ( Figs 3 , 10 ); aedeagus as in Figs 16 a–e, with left lateral lobe long, slender, nearly as long as median lobe, and with setal fringe not extending to midlength ( Fig. 16 d)................................................... L. angustus

3 Elytra with maculation consisting of yellow to reddish-brown bands extending from lateral margins nearly to elytral suture, not, or very weakly, obliquely projected, rarely reduced to spots ( Figs 5, 6 ); robust, L/GW = 1.93–2.07, PNWpost/PNWant = 1.64–1.68........................................................................................... 4

- Elytral maculation usually reduced to spots, most often in basal half; spots or bands obliquely oriented, more so in distal half ( Figs 7–9 ); slender ( Figs 7–9 ), L/GW = 2.00–2.29, PNWpost/PNWant = 1.53–1.62................................. 5

4 Aedeagus as in Figs 18 a–e, with median lobe distally expanded and bluntly rounded at apex ( Figs 18 a–c); left lateral lobe with setal fringe restricted to distal half ( Fig. 18 d); right lateral lobe triangular, with distal angle sharply rounded and not strongly projected ( Fig. 18 e)............................................................................ L. bicolor

- Aedeagus as in Figs 19 a–e, with median lobe weakly expanded distally before attenuating to rounded apex ( Figs 19 a–c); left lateral lobe with setal fringe extending along inner dorsal margin to midlength ( Fig. 19 d); right lateral lobe subtriangular, moderately emarginated along length of dorsal margin, distal angle projecting with apex rounded ( Fig. 19 e)........ L. armulatus

5 Eyes large (HW/EW = 1.60–1.67) ( Fig. 7 ); elytral maculation with posterior bands or spots extending anterolaterally nearly to basal half of elytra ( Fig. 7 ); aedeagus as in Figs 20 a–e, with median lobe slender and not sinuate in dorsal aspect ( Fig. 20 b), weakly expanded before gradually attenuating to elongate apex ( Figs 20 a, c); left lateral lobe slender ( Fig. 20 d); right lateral

lobe triangular and distal angle not projecting ( Fig. 20 e)................................................ L. clayae - Eyes small (HW/EW = 1.47–1.55) ( Figs 8, 9 ); posterior bands or spots extending anterodistally beyond middle of elytra onto basal half at lateral extreme............................................................................. 6

6 Aedeagus as in Figs 21 a–e, with median lobe distally shortened and attenuate in lateral aspect ( Figs 21 a, c); left lateral lobe broad ( Fig. 21 d); right lateral lobe subtriangular with distal angle strongly projecting ( Fig. 21 e)................ L. nanops

- Aedeagus as in Figs 22 a–e, with median lobe distally lengthened and subparallel in lateral aspect Figs 22 a, c); left lateral lobe less broad and distally attenuate ( Fig. 22 d); right lateral lobe triangular with distal angle acute, not projecting ( Fig. 22 e).............................................................................................. L. octoguttatus

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.