Hughleechia Perkins, 1981

Perkins, Philip D., 2007, A revision of the Australian intertidal water beetle genus Hughleechia Perkins (Coleoptera: Hydraenidae), Zootaxa 1527, pp. 17-29 : 19-20

Hughleechia Perkins, 1981

Hughleechia Perkins, 1981: 299 (type species Hughleechia giulianii Perkins, 1981 , by original designation).

Diagnosis. Members of Hughleechia can be recognized by the combination of the short maxillary palpi, the absence of a lateral hyaline border on the pronotum, the arcuate posterior border of the pronotum which lacks distinct posterior angles and has a hyaline border, and the ESDS components of the antennal pocket, including a transgenal ridge (see Perkins 1997 for other characters).

Description. Body form elongate oval, depressed.

Head with distinct ocelli next to protuberant eyes; dorsum of head flat, frons and clypeus in same plane. Maxillary palpus short, palpomere 1 very small, 2 shorter than or subequal in length to 3, 3 broader than other palpomeres, 4 (last) slightly shorter than 3. Nine antennomeres: 2 basal, 1 small intermediate, 1 small cupule, and 5 pubescent segments forming a compact club.

Pronotum with anterior margin weakly rounded in middle, posterior margin much more strongly rounded; anterior and posterior margins with narrow ( H. giulianii ) or moderately wide ( H. gracilis ) hyaline border, sides lacking hyaline border; disc with shallow median longitudinal depression which is slightly constricted at midlength; lateral fossulae well developed; pronotal surface with moderately dense and moderately long to very long hairs, except hairs absent in median depression and in lateral fossulae.

Elytra ovoid or elongate, fused together at weakly raised suture; each elytron with ca. eight rows of punctures, except rows 6–8 much less distinct than discal rows, sometimes random; each puncture with a short, stiff, recumbent seta ( H. giulianii ) or a long, slender and flexible seta ( H. gracilis ) ( Figs. 5, 6 ). Flight wings absent.

Prosternum slightly and evenly elevated in midline, not carinate; procoxae contiguous. Mesoventrite narrow to broad between mesocoxae, with or without carinae; hydrofuge pubescent. Metaventrite reduced, length in midline approximately equal to that of mesoventrite; intercoxal process moderately to very broad; metacoxae narrowly ( H. gracilis ) to widely ( H. giulianii ) separated; hydrofuge pubescence entirely covering metaventrite, or restricted to lateral areas and narrow band along edge of mesocoxal cavities.

Abdomen with seven sternites; intercoxal sternite narrow, or broader than long; sternites 1–4 entirely hydrofuge pubescent, or with hydrofuge pubescence restricted to sides; segment 5 totally hydrofuge pubescent; segments 6 and 7 with a few sparse hairs.

Legs rather long. Tarsi long, slender for most of length, but distinctly broadened apically; tarsal formula 5-5-5; tarsomeres 1–3 very small, combined length slightly longer than, or subequal to length of tarsomere 4; tarsomere 5 longer than other segments combined.

Structures examined in microslide mounts (terminology as in Perkins, 1997): Head with distinctive transgenal ridge and more-or-less developed secretion sulcus or pores ( Figs. 9 , 12 , z). Three to four elongate secretion delivery setae in H. giulianii ( Fig. 7 , a); two or three setae in H. gracilis , shorter than those of H. giulianii , which sometimes become stuck together in dry specimens ( Figs. 11–13 ). Postocular hydrofuge (t) asperite and cuticle with exocrine pores (p) near base of secretion delivery setae. Hypomeral antennal pocket ( Fig. 7 , 11 ) well developed, cuticle smooth except microreticulate medially and hydrofuge pubescent anteromedially. Exocrine pores moderately dense in antennal pocket. Hypomeral hyaline border moderately large ( Fig. 11 , o) to quite large anteriorly ( Fig. 7 , o), in latter condition it contacts postocular secretion delivery setae. Hypomeral hyaline border posteriorly quite narrow, becoming contiguous with posterior hyaline bor- der. Posterior border of pronotum arcuate such that there are no posterior angles. Hypomeral hyaline border and anterior hyaline border contiguous ( H. gracilis ), or separated ( H. giulianii ). Wet-hypomeron well developed. Lateral hyaline border absent. Hypomeral antennal pocket setae slightly ( Fig. 7 , H. giulianii ) to well extended ( Fig. 11 , H. gracilis ) beyond hypomeral hyaline border. Profemur lacking distal spine cluster, spines in this area small, as are others on the profemur.

Figures

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

FIGURES 7 – 9. Hughleechia giulianii. — 7. Ventral view of right eye, antennal pocket, and associated ESDS structures. — 8. Ventral view of antenna, head and prothorax. — 9. Detail of transgenal ridge and postocular secretion delivery setae (a, secretion delivery setae; i, hypomeral antennal pocket; n, prosternum; o, hypomeral hyaline border; t, postocular asperite hydrofuge; u, first antennomere; z, transgenal ridge, with exocrine secretion sulcus).

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).