Laccobius (Glyptolaccobius) guttalis, 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 : 611-612

Laccobius (Glyptolaccobius) guttalis sp. nov.

( Figs. 1 , 7 )

Type locality. Central Nepal, Bagmati, Sindhupalchok, Sarmatang, 2500 m a.s.l..

Type material. HOLOTYPE: J ( NKME): ‘C. NEPAL, Bagmati / Sindhupalchok / 2500 m, Sarmatang / 03–08.VI.1989 / leg. C. Holzschuh’.

Description. Total length 2.15 mm, total width 1.25 mm. Maximum length / maximum width ratio 1.7. Body wide oval, convex, maximum width in anterior elytral third.

Head. Coloration entirely black, with rare and inconspicuous punctures; shining, smooth without microsculpture; ‘systematic punctures’ indistinct; anterolateral branches of frontoclypeal suture conspicuous and punctate at 100×. Labrum black, trapezoid, without specula; anterior margin nearly straight, slightly emarginated medially; lateral margins oblique, posterior margin crescent-shaped. Eyes oblong, oblique, closest to each other posteriorly, not protruding laterad, interocular distance equal to 2.5× of width of one eye; postocular portion of tempora short. Mentum flat, smooth without punctures, emarginated anteriorly. Submentum and gula microgranulate. Maxillary palpi yellow-brown; palpomere 1 thin and short; palpomeres 2 and 3 nearly equal in length; palpomere 3 dilated at apex; palpomere 4 elongate, nearly twice as long as palpomere 3, asymmetrical, inner margin straight and outer margin convex, apex truncate. Eight antennomeres; scape longer than antennomeres 2–4 combined; pedicel cone-shaped; intermediate antennomeres (antennomeres 3–4) very short; cupule asymmetrical, oval in ventral view, crescent-shaped and emarginate in dorsal view; antennal club loose, bearing densely arranged setae, antennomeres 6 and 8 nearly equal in length, antennomere 6 wider, antennomere 7 shorter and narrower.

Thorax. Pronotum transverse, 0.35× as long as wide; black with yellowish lateral margins, yellow margin widened posteriorly and continuing as fine yellow strip along base; surface smooth, without microsculpture, with some sparse and faint punctures. Prosternum black, with longitudinal keel. Scutellar shield equilateral, black, bearing very small punctures. Mesoventrite with longitudinal keel simple, not tuberculate anteriorly. Elytra combined slightly elongate, ca 1.20× as long as wide; shining black with yellowish-brown lateral margins and apices, and pale yellow dots and stripes; 10 longitudinal rows of setiferous, more impressed punctures alternating with 10 rows (interstriae) of sparser and fainter punctures. Parasutural space covered by oblique lines reaching first punctural row in anterior fourth and then forming a flat and shining stripe separating suture from parasutural furrow, stripe and furrow disappearing just before elytral apex. Epipleura and pseudoepipleura oblique, nearly vertical. Metaventrite setiferous, with median longitudinal glabrous area posteriorly.

Legs. Fore coxae and trochanters granulate, pubescent; fore femora setiferous on basal third, smooth distally, with tibial groove; fore tibiae smooth, with stiff setae and two apical spurs. Middle femora with tibial grooves; ventral face of middle tibiae with three longitudinal rows of stiff setae and sulcus between two longitudinal ridges. Hind trochanters smooth and shining; hind femora smooth, with scarce punctures and tibial grooves; hind tibiae curved, ventral face with three longitudinal rows of stiff setae and longitudinal sulcus between two ridges.

Abdomen. Ventrites 1–4 smooth, with lateral setae; ventrites 5–6 wrinkled.

Aedeagus ( Fig. 1 ). Total length 0.68 mm. Parameres slightly longer than phallobase, slightly overlapping apex of median lobe. Median lobe narrow, slightly widened in apical 0.4, with longitudinal excision ventrally; apical portion broadly rounded.

Differential diagnosis. Laccobius guttalis sp. nov. belongs to a group of species with curved hind tibiae, longitudinal rows of elytral punctures and black elytral surface with yellowish dots and stripes (together with L. josefi sp. nov., L. munus and L. sharmai ). It differs from the other three species by the presence of transverse lines in the anterior part of the parasutural stripe and the shape of the aedeagus, with the apical portion of the median lobe swollen and the median lobe bearing a longitudinal ventral excavation ( Fig. 1 ).

Etymology. From a drop (Latin: gutta), alluding to the preferred seepage habitat of Glyptolaccobius .

Bionomics. Unknown.

Distribution. Known only from the type locality in Nepal.

Figures

Figs. 1–3. Aedeagus (a – ventral view, b – dorsal view, c – lateral view). 1 – L. guttalis sp. nov.; 2 – L. hanka sp. nov.; 3 – L. josefi 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.