Hughleechia gracilis, Perkins, Philip D., 2007

Perkins, Philip D., 2007, A revision of the Australian intertidal water beetle genus Hughleechia Perkins (Coleoptera: Hydraenidae), Zootaxa 1527, pp. 17-29 : 25-28

Hughleechia gracilis new species

( Figs. 2 , 4 , 6 , 10–14 )

Type Material. Holotype (male): AUSTRALIA: Tasmania: West Point, SW Marrawab, 1 meter, ocean beach, pyrethrin fogging high intertidal rock faces, 40° 57' S, 144° 37' E, 28 January 1993, A. Newton & M. Thayer. Deposited in the ANIC. Paratypes (39): AUSTRALIA: Tasmania: same data as holotype (29 ANIC, FMNH, MCZ). Spiky Beach, S. of Swansea, 1 meter, ocean beach; pyrethrin fogging south-facing high intertidal rock face (mostly bare), 42° 11' S, 148° 4' E, 2 February 1993, A. Newton & M. Thayer (10 FMNH, MCZ).

Differential Diagnosis. Immediately differentiated from H. giulianii by the narrower body form and smaller size ( Figs. 1 , 2 ). Also differing from H. giulianii by the comparatively large clypeus and labrum, the different proportions of the maxillary palpi, the long and thin dorsal setae of the elytra ( Figs. 5, 6 ), the presence of mesoventral carinae, the narrow mesoventral intercoxal process, and differences in the ventral hydrofuge pubescence.

Description. Size (length/width, mm) holotype: body 1.42/0.48; head 0.24/0.27; pronotum 0.36/0.39; elytra 0.79/0.48. Dorsum black, venter and legs dark brown.

Dorsal setae very long, very fine, recumbent, sparse on head, moderately dense on pronotum. Frons smooth between setiferous punctures; interocular foveae subparallel impressed lines, are between foveae flat; interocular tuberculi well developed, adjacent to posteromedian margin of eyes. Frontoclypeal suture markedly bisinuate. Clypeus length/width as 6/13. Labroclypeal suture weakly arcuate. Labrum length 1/3 width; apicomedially weakly emarginate and weakly depressed behind emargination; surface of labrum smooth and shiny. Maxillary palpus with penultimate segment very wide; ultimate segment much smaller, tapering to apex, ca. 1/2 length of penultimate. Mentum ( Fig. 10 ) produced at sides, deeply notched on anterior margin, shiny, sparsely punctate. Submentum shiny. Genae swollen, shiny. Postgena pubescent, punctulate.

Pronotum with very long, very fine setae except median longitudinal area, cuticle moderately smooth; anterior margin weakly arcuate, with moderately wide hyaline border; sides strongly convergent from midlength; posterior margin with moderately wide hyaline border that is overlaid with a row of setae; lateral fossulae delimiting lateral lobes well developed, smooth except for a few punctures anteriorly.

Elytra interlocked, distinctly declivous in apical 1/4, humeri obsolete; each elytron with eight rows of large, slightly irregularly outlined punctures; each puncture with a long, very fine, recumbent seta; anterior margin of each setal socket raised in tiny granule; suture very slightly raised. Explanate margin very narrow.

Prosternum evenly rounded in midregion, antennal pockets well developed; coxae contiguous. Mesoventrite pubescent, intercoxal process narrow; one sublateral carina on each side, extended from anterior margin, but not attaining posterior margin. Metaventrite entirely hydrofuge pubescent; intercoxal process triangular; posteromedian area between metacoxae triangularly incised to receive very narrow intercoxal sternite.

Abdominal sternites 1–5 finely asperite and hydrofuge pubescent.

Legs moderately long and slender. Tarsi broadened apically, claws large. Segment 5 (last) of all tarsi longer than respective basal segments combined. Segment 4 slightly shorter than combined lengths of segments 1–3.

Aedeagus ( Fig. 4 ) with parameres originating near basal 1/3 of main piece.

Distribution. Currently known from one northwestern and one eastern locality on the Tasmanian coast ( Fig. 14 ).

Etymology. Named in reference to the slender body form and slender dorsal setae.

Figures

FIGURE 1. Hughleechia giulianii, holotype. Dorsal and lateral habitus.

FIGURE 2. Hughleechia gracilis, holotype. Dorsal and lateral habitus.

FIGURE 14. Geographical distributions of Hughleechia giulianii and H. gracilis.

FIGURES 3 – 4. Hughleechia, aedeagi of holotypes. — 3. H. giulianii. — 4. H. gracilis.

FIGURES 5 – 6. Hughleechia, elytron punctation pattern and microsculpture detail. — 5. H. giulianii. — 6. H. gracilis.

FIGURES 10 – 13. Hughleechia gracilis. — 10. Ventral view of head. — 11. Ventral view of right eye, antennal pocket of prothorax, and associated ESDS structures. — 12. Detail of transgenal secretion ridge and forked postocular secretion delivery setae on left side. — 13. Same, on right side (a, secretion delivery setae; o, hypomeral hyaline border; z, transgenal ridge, with exocrine secretion pores).