Laccophilus isamberti, Bistroem, Olof, Nilsson, Anders N. & Bergsten, Johannes, 2015

Bistroem, Olof, Nilsson, Anders N. & Bergsten, Johannes, 2015, Taxonomic revision of Afrotropical Laccophilus Leach, 1815 (Coleoptera, Dytiscidae), ZooKeys 542, pp. 1-379 : 41-43

Taxon classification Animalia Coleoptera Dytiscidae

Laccophilus isamberti sp. n. Figs 7, 43-44, 245-246, 397, 533

Type locality.

Madagascar: Zahamena N.P., Ambatondrazaka. (N: - 17,50800 E: 48,72283).

Type material studied

(23 exs.): Holotype: male: "MAD TOAM: Ambatondrazaka Zahamena: Zahamena N.P. close to Camp site 1 Manambota River, on the Rocks. PB60BI01: N: - 17,50800 E: 48,72283: 943 m 28.XII. 2006 Leg. Isambert et. al. / Laccophilus sp.n. lateralis gr. Det. J. Bergsten. 2008" (NHRS, habitus in Fig. 397). - Paratypes: Same data as holotype (4 exs. NHRS, 2 exs. MZH); same data as holotype and "DNA VOUCHER BMNH(E) <834433> MSL:430:G02" (1 ex. BMNH); same data as holotype, but "<834432> MSL:430:G01" (1 ex. BMNH); "MAD TOAM: Ambatondrazaka Zahamena: Zahamena N.P. Analamaintsoa Forest between Camp Site 1 and Camp Site 2 Manambota River. PB60BI02: N: - 17,50750 E: 48,72250: 1071 m 29.XII. 2006 Leg. Isambert et al. / Laccophilus sp.n. lateralis gr. Det. J. Bergsten 2008/DNA VOUCHER BMNH(E) <834434-7> MSL:430:G03-6" (3 exs. BMNH, 1 ex. MZH); same data but not vouchers (1 ex. NHRS, 1 ex. NMW); same data but ”P60BI04” (2 exs. NHRS, 1 ex. NMW); "MAD TOAM: Ambatondrazaka Zahamena: Zahamena N.P. Analamaintsoa Forest Manambota Rv, 500 m between Camp 1 & Camp 2 PB60BI11 30.XII. 2006 N: - 17,50717 E: 48,72400 leg. Isambert et al. / Laccophilus sp.n. lateralis gr. Det. J. Bergsten, 2008/DNA VOUCHER BMNH(E) <834438> MSL:430:G07" (1 ex. BMNH); same data but not vouchers (2 exs. NHRS); "MAD TOAM: Ambatondrazaka Zahamena: Zahamena N.P. Analamaintsoa Forest 5th stream between Camp 1 and Camp 2 PB60BI16 31.XII. 2006 N: - 17,52183 E: 48,72067 1092 m leg. Isambert et al. / Laccophilus sp.n. lateralis gr. Det. J. Bergsten, 2008/DNA VOUCHER BMNH(E) <834439> MSL:430:G08" (1 ex. BMNH).

Diagnosis.

A deviating species, which on the basis of external appearance and shape of penis may be closely related to species group 4 ( Laccophilus alluaudi ). Laccophilus isamberti , however, exhibits peculiar modification on metacoxal process, being posteriorly expanded (Fig. 7). This feature is lacking in all other African Laccophilus species and accordingly the location within the genus Laccophilus can also be discussed. Further study is definitely needed to establish the status of the species Laccophilus isamberti .

Description.

Body length 3.7-4.0 mm, width 2.2-2.4 mm. Dorsal colour pattern of body (Fig. 397); minor variation observed in width of elytral, longitudinal markings.

Head: Posteriorly dark brown; anteriorly head becomes gradually paler. Rather shiny, although finely microsculptured. Reticulation indistinctly double; large meshes generally quite distinct while small meshes in part indistinct. When discernible, large meshes contain 2-4 small meshes. At eyes with fine, irregular punctures. Area with punctures extended from eyes towards middle of head but they don’t meet medially.

Pronotum: Blackish ferrugineous to dark ferrugineous, laterally broadly paler; ferrugineous to pale ferrugineous. Slightly mat, finely microsculptured. Reticulation indistinctly double. Small meshes distinct; large meshes strongly reduced and almost absent, only slightly stronger developed than small meshes. Large meshes, when discernible, contain 2-4 small meshes. Impunctate, except at margins with fine, irregular punctures (mediobasally, punctures also absent).

Elytra: Blackish to dark ferrugineous, with pale ferrugineous, longitudinal markings. Posteriorly markings undulate (Fig. 397). Width of longitudinal markings slightly variable. Slightly mat, finely microsculptured. Reticulation double, but large meshes strongly reduced and almost absent. Fine, scattered punctures form a discal row. Dorsolateral and lateral rows indicated by a few scattered punctures. Lateral, pre-apical furrow shallow, rather finely pubescent.

Ventral aspect: Blackish to dark ferrugineous; without distinct colour pattern. Rather shiny, very finely microsculptured. Reticulation in part absent. Abdomen basally with fine, curved striae. Almost impunctate; ventrites with fine punctures. Apical ventrite as in Fig. 43. Prosternal process quite narrow, apex only moderately extended, apex pointed, Metacoxal plates in anterior half with four outwards curved, distinct furrows; in posterior half furrows strongly reduced. Metacoxal process posteriorly expanded (Fig. 7).

Legs: Pro- and mesotarsus slightly enlarged, with suckers.

Male genitalia: Shape of penis (Figs 245-246) resembles some of the species located in species group 4 and especially the species Laccophilus pictipennis , placed in an own species group 6.

Female: Pro- and mesotarsus slender. Apical ventrite as in Fig. 44.

Etymology.

The name is a noun in its genitive form based on the name of Dr. Benjamin Isambert, Toulouse, France, who collected the type material during his PhD studies.

Distribution.

Madagascar, so far only known from Zahamena National Park (Fig. 533).

Collecting circumstances.

This is a lotic species occurring in rivers and streams. The known localities are at an altitude of 1000-1100 m.