Laccophilus rivulosus Klug, 1833

Bistroem, Olof, Nilsson, Anders N. & Bergsten, Johannes, 2015, Taxonomic revision of Afrotropical Laccophilus Leach, 1815 (Coleoptera, Dytiscidae), ZooKeys 542, pp. 1-379 : 77-79

Taxon classification Animalia Coleoptera Dytiscidae

Laccophilus rivulosus Klug, 1833 Figs 63-64, 257, 416, 542

Laccophilus rivulosus Klug 1833: 48 (original description, faunistics); Aubé 1838: 4 (description, faunistics); Sharp 1882: 287, 821 (description, faunistics); Kolbe 1883: 401 (description, faunistics); v. d. Branden 1885: 24 (catalogue, faunistics); Régimbart 1895: 136, 140 (discussion, description, faunistics); Régimbart 1903: 14 (faunistics); Zimmermann 1919: 122 (faunistics); Zimmermann 1920a: 25 (catalogue, faunistics); Guignot 1937: 141 (discussion); Guignot 1959a: 544 (description, faunistics); Bertrand and Legros 1971: 245 (faunistics, biology); Rocchi 1991: 86: (faunistics, list); Nilsson 2001: 250 (catalogue, faunistics); Nilsson 2015: 217 (catalogue, faunistics).

Type locality.

Madagascar.

Type material studied

(4 exs.): Lectotype (by present designation): male: "9982 / Typus / Laccophilus rivulosus Kl. Madag, Goudot / Hist-Coll. ( Coleoptera ) Nr. 9982 Laccophilus rivulosus Kl. Madagascar Goudot Zool. Mus. Berlin" (ZMHB). - Paralectotypes: Madagascar Goud. Nr. 9982 / Typus / Hist-Coll. ( Coleoptera ) Nr. 9982 Laccophilus rivulosus Kl. Madagascar Goudot Zool. Mus. Berlin" (3 exs. ZMHB).

Additional material, studied

(38 exs.). Madagascar: "Antakotako II 1936" (1 ex. MNHN; habitus in Fig. 416); "Mad. Sud, Ft Dauphin Alluaud 1900" (3 exs. MNHN); "Mad. Sud, Ft Dauphin Alluaud" (2 exs. MNHN); "Tamatave Perrot" (1 ex. Z MHB, 2 exs. MNHN); "Antsianaka Perrot Freres, 1er Semestre 1892" (1 ex. MNHN, 1 ex. NHMB, 6 exs. SAMC); "Antsianaka / Laccophilus rivulosus Kl. det. M. Brancucci" (1 ex. MNB); “Suberbieville” (1 ex. MNHN); "Mt. d’Ambre / Mai" (1 ex. ZMHB); "St. Marie Moaroay / Mad. Kaudern / Laccophilus rivulosus Kl. det. Zimmermann" (4 exs. NHRS); "Mahajanga Melaky, btw Bekopaka-Antsalova, S18.91556, E044.55546, 47 m.a.o. 16.12. 2009 water net, field Bergsten et al." (2 exs. NHRS); same data but add "NHRS-JLKB 000000726" (1 ex. NHRS); "Mahajanga Melaky, btw Antsalova-Maintirano S18.30233, E044.18071, 37 m.a.o., 18.12. 2009, water net, field, Bergsten et al. /NHRS-JLBK 000000728" (1 ex. NHRS); "Mahajanga Boeny, Ankarafantsika NP, S16.30341, E046.81073, 74 m.a.o., 29.11. 2009, 22 W black light, field, Bergsten et al." (1 ex. NHRS); same data but " S16.31215, E046.81523, 76 m.a.o., water net, field" (2 exs. NHRS); same data but " S16.31215, E046.81523, 76 m.a.o., water net, field/NHRS-JLKB 000000724" (1 ex. NHRS); "Mahajanga Boeny, Mahavavy Kinkony RS, S16.06651, E045.77672, 24 m.a.o., 5.12. 2009, water net, field, Bergsten et al./NHRS-JLKB 000000727" (1 ex. NHRS); "Toliara Menabe, Kirindy R. S., S20.07641, E044.674708, 65 m.a.o., 11.12. 2009 water net, field, leg. Bergsten et al" (2 exs. NHRS); "FIAN, Isalo, Piscine Noir, hygropetric 12.5. 2006 Bergsten et al. /BMNH(E) <794159> DNA voucher / Laccophilus rivulosus Kl. det. Bergsten" (1 ex. NHRS); "Madagascar Fairmaire / Laccophilus rivulosus Kl. Madg." (1 ex. NMW); "Madag. Perrier" (2 exs. SAMC).

Diagnosis.

Laccophilus rivulosus is characterized by large body, peculiar elytral colour pattern and shape of penis. Dark longitudinal markings of elytra are quite broad and distinct. Pale irrorations can generally be discerned within dark, longitudinal marking. Penis resembles much of penis of Laccophilus posticus but it is somewhat larger and extreme apex more extended. Additionally large body size and clear differences in elytral colour pattern easily separates Laccophilus rivulosus from Laccophilus posticus .

Description.

Body length 4.8-5.3 mm, width 2.7-3.0 mm. Dorsal colour pattern of body generally distinct and uniform (Fig. 416); rarely slightly variable.

Head: Pale ferrugineous, posteriorly between eyes with a distinctly delimited blackish ferrugineous to dark ferrugineous area. Rarely dark area reduced and only in part visible because hidden beneath frontal part of pronotum. Almost impunctate. At eyes in shallow depression with fine, irregularly distributed punctures. Submat, rather distinctly microsculptured. Reticulation double. Coarser meshes only slightly stronger in comparison with fine meshes. In part, kinds of meshes difficult to separate. When discernible coarse meshes contain 3-5 fine meshes.

Pronotum: Pale ferrugineous, frontally with a distinct, dark ferrugineous area. Posteriorly in middle with an, often, bilobed, dark ferruginoeus, narrow spot. Almost impunctate. No distinct punctation discernible. Submat, finely microsculptured. Reticulation double. Coarse meshes well developed, contain 2-5 fine meshes.

Elytra: Pale ferrugineous, with distinct, longitudinal, dark ferrugineous markings. Dark markings somewhat undulate and merged into pairs, forming pale, inner, irrorations (Fig. 416). Rarely undulation in anterior half of elytra indistinct because of expanded dark areas. Almost impunctate; an indistinct, discal row of punctures discernible. Rather shiny, although distinctly microsculptured. Reticulation double. Coarse meshes contain 2-5 fine meshes. Narrowly at suture elytra slightly elevated.

Ventral aspect: Pale ferrugineous. Almost impuntate; abdomen with a few scattered punctures. Rather shiny, although extensively, finely microsculptured. In part microsculpture almost obliterated or totally obliterated. Abdomen laterally with fine, curved striae. Apical ventrite as in Fig. 63. Prosternal process rather slender, apex pointed but not strongly extended posteriorly. Metacoxal plates with about 10 furrows, of which 2-3 closest to metasternal wing are distinct while others rather indistinct to indistinct.

Legs: Pro- and mesotarsus slightly enlarged, somewhat extended and provided with some protruding suckers.

Male genitalia: Penis quite robust, in lateral aspect distinctly curved and apex extended and sharp (Fig. 257).

Female: Apical ventrite as in Fig. 64. Pro- and mesotarsus rather slender, extended.

Distribution.

Endemic for Madagascar (Fig. 542).

Collecting circumstances.

Information on biology is almost totally lacking. Bertrand and Legros (1971) reports the species from a small swamp and from pools of a temporary river.