Gymnanthelius lamingtonensis, Perkins, Philip D., 2004

Perkins, Philip D., 2004, A revision of the Australian endemic water beetle genus Gymnanthelius Perkins (Coleoptera: Hydraenidae), Zootaxa 585, pp. 1-39 : 12-13

Gymnanthelius lamingtonensis new species

( Figures 4 , 12 , 20 )

Type Material. Holotype (male): Australia, Queensland, Lamington, Binna Burra, 28.15S – 153.06E, Comera River, stones, 17.xi.1982, S. Endrödy­Younga ( QMBA). Paratypes: Same data as holotype (3 TMSA).

Diagnosis. Recognized by the elytral punctures in series, the shining dorsal reliefs, and the pronotal median groove shape, which is widest near base, tapering anteriorly to a point. Most similar to G. c u p re u s; refer to the diagnosis of that species for comparison.

Description. Holotype 1.71 x 0.75; head length 0.44, width 0.33; pronotum midlength 0.37, maximum width 0.54 just behind anterior angles; elytra length 1.00, maximum width 0.75. Form moderately ovate, transversely moderately convex. Dorsum brown with cupreus and aureus metallic reflections.

Eyes moderately large, in dorsal aspect 7 convex facets in longest series. Clypeus and frons reliefs moderately coarsely densely punctate, punctures on clypeus c. 0.5– 2 x eye facet, interstices dull; each puncture on disc with short very indistinct recumbent seta, laterally on clypeus setae denser and more apparent. Frons reliefs with interstices between punctures shining; interocular foveae large, each nearly as wide as distance separating them, outer margins gradual, inner margins abrupt, bottom with vaguely 8­shaped pit. Area between interocular foveae flat on discal part. Ocelli large, slightly oval, contiguous with inner margin of eye. Labrum anteriorly produced in two slightly reflexed lobes separated by U­shaped median emargination, each lobe slightly longer than last maxillary palpomere, setae distinct on disc, laterally forming narrow fringe.

Pronotum anterior margin arcuate over middle, slightly emarginate before anterior angles, hyaline border well developed. Lateral depression 3.5x as wide anteriorly as posteriorly, side emarginate before tooth­like posterior angle. Lateral hyaline border well developed, anterior extreme nearly attaining anterior angles, continuing in rather uniform width along sides, widest just behind lateral depression, in dorsal aspect margin oblique to midline, nearly straight except slightly indented opposite posterior extreme of lateral depression. Lateral fossulae deep, shining, inner margin abrupt, outer margin obsolete; without anterior or posterior pit. Disc transversely convex, gradually widening from anterior to about middle, then sides converging but only very slightly so to base; densely coarsely punctate, punctures c. 1.5x eye facet, interstices dull, effacedly mcr., c. 1x puncture diameter. Median groove constricted in middle, distinctly wider posteriorly than anteriorly, each end tapering and not attaining respective hyaline border. Anterior foveae very shallow, indistinct, punctate, each 2x width of median groove at same level, separated from median groove by c. 1x fovea width. Posterior foveae absent or location only faintly indicated by slightly denser punctures.

Elytra widest at middle, sides regularly arcuate; explanate margin narrower than metatibia, declivous, surface flat or only slightly transversely convex, origin just behind anterolateral angles, becoming obsolete near posterior 0.2, without discernable setae. Apices conjointly sharply rounded. Transversely very convex, posterior declivity rather abrupt. Series 2–3 terminating beyond summit of posterior declivity, 1 and 4 attaining apices. Serial punctures large, c. 2x eye facet, deep, striate­impressed, especially deeply in basal 0.3 and sutural series, each puncture also bearing indistinct short recumbent seta which just attains base of next seta in series. Intervals shining, transversely rounded, width equal puncture width.

Metasternal glabrous area length equal width, widest behind midlength. Ventrites 1–4 with hydrofuge pubescence.

Aedeagus: Length 0.35 mm.; mainpiece sinuate, relatively narrow, apex asymmetrically rounded; tube weakly expanded apically; parameres with distal pair of setae long, subequal in length, straight and slightly thickened ( Fig. 12 ).

Etymology. Named in reference to the known geographical distribution.

Distribution. Currently known only from the type locality in Lamington National Park, southernmost Queensland ( Fig. 20 ).

Figures

FIGURE 4. Gymnanthelius lamingtonensis holotype. Dorsal and lateral habitus.

FIGURES 10 – 13. Gymnanthelius, aedeagi of holotypes. — 10. G. clypeatus. — 11. G. opacicollis. — 12. G. lamingtonensis. — 13. G. cupreus.

FIGURES 18 – 21. Gymnanthelius geographical distributions. — 18. G. clypeatus. — 19. G. cupreus. — 20. G. lamingtonensis. — 21. G. porchi.