Laccobius (Glyptolaccobius) sipeki, Gentili & Fikaček, 2009

Gentili, Elio & Fikaček, Martin, 2009, Taxonomic notes on Laccobius, subgenus Glyptolaccobius, with new records and description of four new species (Coleoptera: Hydrophilidae), Acta Entomologica Musei Nationalis Pragae 49 (2), pp. 607-623 : 618-622

Laccobius (Glyptolaccobius) sipeki sp. nov.

( Figs. 6 , 10 )

Type locality. India, Meghalaya, Khasi Hills, Laitkynsew, 11 km SW of Cherrapunjee.

Type material. HOLOTYPE: J ( NMPC): ‘INDIA, Meghalaya State (6) / E Khasi Hills, 11 km SW Cherra- / punjee, Laitkynsew, 21–24.IV. / 2008, 25°12′N, 91°40′E, 460 m / Fikáček, Podskalská, Šípek lgt. // wet rock with algae/ blue algae / and fallen leaves at side of / waterfall on small river surround. / by tropical forest, ca. 200m / upstream from living bridge’ . PARATYPE: INDIA: MEGHALAYA: 1 J ( NHMW): ‘INDIA: Meghalaya / SW of Cherrapunjee / 25°13′–14′N 91°40′E, 900m / P. Pacholátko leg. / 5.–24.v.2005 ’.

Description. Small-sized species, body length 1.85 mm, width 1.09 mm. Maximum length / maximum width ratio 1.7. Body oval, moderately convex.

Head. Labrum of males without specula; anteriorly and posteriorly crescent-shaped in dorsal view, shiny black. Clypeus moderately convex, shiny black, with sparse and faint punctures, without distinct ‘systematic punctures’. Only terminal branches of frontoclypeal suture conspicuous. Frons shiny black with sparse and faint punctures as those on clypeus. Eyes oblique, weakly convex, not protruding laterad, separated by distance equal to 2.5× of width of one eye, nearly reniform in lateral view, emarginated posteriorly. Maxillary palpi less than 0.5× as long as head width; palpomere 2 slightly swollen, nearly as long as palpomere 3; palpomere 4 1.5× as long as palpomere 3, outer and inner margin rounded, with ogival apex. Mentum ca 0.5× as wide as long, almost flat, at least medially, covered with faint punctures. Eight antennomeres; scape longer than antennomeres 2–4 combined; pedicel cone-shaped; two intermediate antennomeres (antennomeres 3–4) very short; cupule asymmetrical, oval in ventral view, crescent-shaped and emarginate in dorsal view; antennal club loose, with antennomeres 6 and 8 nearly equal in length, antennomere 6 wider, antennomere 7 shorter and narrower.

Thorax. Pronotum without distinct ‘systematic punctures’, covered with sparse and faint punctation, interstices smooth and shining; black in centre and along posterior margin, yellow coloration of lateral margins widening posteriorly. Prosternum well developed, tectiform medially, bearing fine but distinct median carina. Scutellum black, equilateral. Mesoventrite reaching anterior mesothoracic margin at single point, rather flat with longitudinal carina between mesocoxae raised to small acute tooth slightly anterior to mesocoxae. Metaventrite with weakly raised middle portion slightly projecting anteriorly between mesocoxae and posteriorly between metacoxae, bearing hydrofuge pubescence except for posteromedian glabrous area on raised middle portion. Anepisternum 3 ca. 4.5× as long as wide, subparallel. Elytra black, with yellowish lateral margins and apices, each elytron with wide parasutural furrow engraved from base to nearly anterior two thirds of elytral length and with ca. 20 longitudinal series of punctures: 10 primary rows consisting of well-discernible setiferous punctures, 10 alternate, scarcely visible rows, consisting of a small number of punctures; lateral margins neither serrate nor denticulate; epipleura oblique, pseudoepipleura nearly vertical and separated by distinct ridge; their anterior dilated portion ending anterior to metacoxae.

Legs. Fore coxae almost contiguous, pubescent; fore trochanters pubescent; middle coxae separated by median carina of mesoventrite; tip of hind trochanters free, not abutted to hind femora. Femora with distinct tibial grooves distally on inner faces; basal third of ventral side of fore femora covered with hydrofuge pubescence; middle and hind femora nearly glabrous. Tibiae relatively short and stout, progressively wider towards apices, spiny, lacking swimming hairs; hind tibiae curved inwards. Middle and hind tarsi nearly without fine and sparse swimming hairs on dorsal face.

Abdomen. Six distinct ventrites, ventrites 1–5 rather shiny and sparsely pubescent, ventrite 6 more rugose, pubescent and somewhat retractable; ventrite 1 not carinate; posterior margin of ventrite 5 subtruncate.

Aedeagus. Total length 0.44 mm. Parameres shorter than median lobe, 1.3× as long as phallobase, outer side nearly straight, inner side strongly diverging in terminal 0.4. Median lobe slender, slightly narrowing apicad, rounded at apex; margins of longitudinal excision bearing long hairs ( Fig. 6 ).

Differential diagnosis. Laccobius sipeki sp. nov. belongs to a group of Glyptolaccobius species with curved hind tibiae and elytra bearing longitudinal rows of punctures (together with L. celsus , L. silvester , L. shorti , L. munus , and L. sharmai ). It differs from the other species by the wide parasutural furrow, not strictly corresponding to a single row of punctures, and by the lack of yellowish dots and stripes near the elytral base and suture; the shape of parameres of this species resembles L. munus , but the divergent interior part is longer.

Etymology. The species is dedicated to Petr Šípek, who collected some of the Glyptolaccobius species described in this paper.

Bionomics. The holotype was collected on a wet rock with algae, blue algae and fallen leaves at the side of a waterfall on a small river surrounded by dense tropical forest ( Fig. 11 ) together with the following beetles: Laccobius pluvialis , L. eliogentilii , L. ( Cyclolaccobius ) sp., Oocyclus sp. , Dactylosternum sp. (Hydrophilidae) , Hydraena sp. (Hydraenidae) , Ceradryops sp. (Dryopidae) and two species of the genus Hydroscapha (Myxophaga: Hydroscaphidae ) ( FIKÁČEK & ŠÍPKOVÁ 2009).

Distribution. India, Meghalaya.

Figures

Figs. 4–6. Aedeagus (a – dorsal view, b – ventral view, c – lateral view). 4 – L. moriyai Kamite, Ogata & Hikida, 2007; 5 – L. pluvialis Gentili, 2006; 6 – L. sipeki sp. nov. Scale bar: 0.25 mm.

Figs.7–10. Habitus of Glyptolaccobius species.7 – L. guttalis sp. nov., male, holotype; 8 – L. moriyai Kamite, Ogata & Hikida, 2007, female; 9 – L. josefi sp. nov., male, paratype; 10 – L. sipeki sp. nov., male, holotype.

Figs. 11–13. Habitats of Glyptolaccobius species.11 – India, Meghalaya, Laitkynsew env., 460 m a.s.l.: type locality of L. sipeki sp. nov., locality of L. pluvialis and L. eliogentilii (arrow indicates the position of the microhabitat where the specimens were collected); 12 – India, Meghalaya, Laitkynsew env., 810 m a.s.l.: exposed seepages at the side of a road, locality with common occurrence of L. pluvialis; 13 – India, Arunachal Pradesh, 1 km N of Bhalukpong: seepages at the road side, type locality of L. hanka sp. nov. and L. josefi sp. nov. Photos by M. Fikáček.