Laccobius (Glyptolaccobius), Gentili, 1989

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 : 609-610

Key to the species of the subgenus Glyptolaccobius

1. Hind tibiae straight. Total length 1.9–2.2 mm. Aedeagus as in GENTILI (2006: Figs. 30–31. ................................................................................... L. senguptai Gentili, 1979

– Hind tibiae curved. Total length 1.4–2.6 mm. ............................................................... 2

2. Elytra with longitudinal rows of punctures. .................................................................. 3

– Elytra with unordered punctures. ................................................................................. 12

3. Rows of punctures sulciform on entire elytra. Mentum rugose.Apices of parameres widely swollen. Total length 2.4–2.6 mm. Aedeagus as in GENTILI (2006: Figs. 12–14 ). ............ ..................................................................................................... L. celsus Gentili, 1989

– Rows of punctures not sulciform or sulciform only near suture. Mentum smooth or microgranulated. Apices of parameres not or scarcely swollen. ................................... 4

4. Entire elytra shiny black, without yellow lateral margins. Apex of median lobe widely swollen ( Fig. 4 ). Total length 2.3–2.5 mm. ....................................................................... ....................................................................... L. moriyai Kamite, Ogata & Hikida, 2007

– At least lateral margins and apex of elytra yellowish. Apex of median lobe swollen or not swollen. Total length less than 2.3 mm. ......................................................................... 5

5. Posterior pronotal margin entirely dark (as in Fig. 10 ). ................................................. 6

– Posterior pronotal margin yellowish at least laterally (as in Figs. 7, 9 ). ....................... 7

6. Elytral base with indistinct yellowish spot. Last maxillary palpomere symmetrical with acute apex ( Fig. 10 ). Aedeagus as in Fig. 6 . Total length 1.8–1.9 mm. ............................ .............................................................................................................. L. sipeki sp. nov.

– Elytral base uniformly black. Last maxillary palpomere asymmetrical, with straight inner margin and convex outer margin.Aedeagus as in GENTILI (2006: Figs 34–35). Total length 2.2–2.3 mm. ............................................................................. L. silvester Gentili, 2006

7. Head with pale preocular spots ( Fig. 9 ). Last maxillary palpomere asymmetrical, with truncate apex. Apex of median lobe widely swollen ( Fig. 3 ). Total length 2.2 mm. ........ ................................................................................................................ L. josefi sp. nov.

– Head entirely black. Last maxillary palpomere symmetrical or asymmetrical. Apex of median lobe swollen or not swollen. .............................................................................. 8

8. Median line of abdominal ventrite 1 bearing vertical thorn (best seen on disarticulated abdomen). Last maxillary palpomere symmetrical, with truncate apex. ....................... 9

– Abdominal ventrite 1 simple, without vertical thorn or median carina. Last maxillary palpomere asymmetrical. ............................................................................................. 10

9. Mentum smooth. Elytra with yellowish dots. Parasutural furrow nearly as long as half of elytral length. One or two elytral striae next to parasutural furrow sulciform at midlength. Aedeagus as in GENTILI (2006: Figs. 23–26). Total length 1.9–2.2 mm. .......................... .................................................................................................... L. munus Gentili, 1995

– Mentum microgranulated. Elytra with yellowish dots and stripes; parasutural furrow nearly as long as one third of elytral length. Elytral striae next to parasutural furrow not sulciform. Aedeagus as in GENTILI (2006: Figs. 32–33). Total length 2.0– 2.2 mm. ......... .................................................................................................. L. sharmai Gentili, 1995

10. Basal fourth of the interval between suture and first elytral punctural row densely microgranulated and covered by oblique transverse lines. Apices of parameres swollen ( Fig. 1 ). Total length 2.1–2.2 mm. ............................................................. L. guttalis sp. nov.

– Parasutural space without microstructure near elytral base. Apices of parameres not swollen. ......................................................................................................................... 11

11. Punctures of secondary elytral rows nearly as large and dense as those of primary rows. Median lobe wide, tongue-shaped, constricted at midlength ( Fig. 2 ). Total length 1.4–1.8 mm. ........................................................................................ L. hanka sp. nov.

– Punctures of secondary elytral rows scarcer and smaller than those of primary rows. Median lobe wide at base, then regularly narrowing apicad ( GENTILI 2006: Figs 36–38). Total length 1.7–2.0 mm. ............................................................. L. shorti Gentili, 2006

12. Elytral surface with pale stripes and dots. Parasutural furrow short, recognizable barely in the posterior fifth of elytra. ...................................................................................... 13

– Elytral surface except margins and apex uniformly dark. Parasutural furrow longer, exceeding the posterior fifth of elytra. ............................................................................ 15

13. Elytra with distinct yellow stripes and spots along suture. Phallobase distinctly shorter than parameres; median lobe straight, without subapical swelling ( GENTILI (2006), Figs. 15–16). Total length 1.6–1.8 mm. ..................................... L. eliogentilii Hebauer, 2002

– Elytra without distinct yellow stripes or spots along suture. Phallobase nearly as long as parameres, or median lobe with subapical swelling. ................................................... 14

14. Each elytron with two yellow/white spots basally; apical half of elytra with yellow-white stripes. Phallobase nearly as long as parameres, median lobe without swelling ( GENTILI (2006: Figs. 20–22). Length 1.7–2.0 mm. .................................. L. jaechi Gentili, 1988

– Each elytron with a slender yellow spot basally; apical half with yellow to chestnut stripes. Phallobase distinctly shorter than parameres, median lobe with subapical swelling ( Fig. 5 ). Length 1.7–2.2 mm. ................................................................ L. pluvialis Gentili, 2006

15. Parasutural furrow not reaching elytral apex. Head and pronotum with light shagreen at 80× magnification. Inner side of parameres with longitudinal subapical excision ( GENTILI 2006: Figs. 8–11 ). Total length 1.8 mm. ................................. L. egregius Gentili, 1995

– Parasutural furrow reaching elytral apex. Head and pronotum smooth, without shagreen at 80× magnification. Parameres without longitudinal excision. ................................. 16

16. Anterior apex of mesoventral keel with vertical tooth. Punctures of head and pronotum bearing black setae. Apex of each paramere hooked at interior side ( GENTILI 2006: Figs. 17–19). Length 1.8–2.1 mm. ..................................................... L. incisus Gentili, 1989

– Anterior apex of mesoventral keel without apparent vertical tooth. Punctures of head and pronotum bearing pale setae. Apices of parameres not hooked ( GENTILI 2006: Figs. 5–7 ). Length 1.7 –2.0 mm. ................................................................... L. affinis Knisch, 1927

Figures

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.

Fig. 14. Known distribution of the Glyptolaccobius species.

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. 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.