Laccophilus trilineola Regimbart , 1889

Bistroem, Olof, Nilsson, Anders N. & Bergsten, Johannes, 2015, Taxonomic revision of Afrotropical Laccophilus Leach, 1815 (Coleoptera, Dytiscidae), ZooKeys 542, pp. 1-379 : 121-123

Taxon classification Animalia Coleoptera Dytiscidae

Laccophilus trilineola Regimbart, 1889 Figs 87-88, 277, 434, 552

Laccophilus trilineola Régimbart 1889: 52 (original description, faunistics); Régimbart 1895: 132 (description, faunistics); Zimmermann 1920a: 27 (catalogue, faunistics); Guignot 1959a: 577 (description, faunistics); Nilsson 2001: 252 (catalogue, faunistics); Nilsson 2015: 218 (catalogue, faunistics).

Laccophilus simulator Omer-Cooper 1958b: 37, 50, 53 (original description, faunistics, biology); Nilsson 2001: 251 (catalogue, faunistics); Pederzani and Reintjes 2002: 40 (faunistics); Nilsson 2015: 218 (catalogue, faunistics). New synonym.

Type localities.

Laccophilus trilineola : Angola: Humpata.

Laccophilus simulator : Malawi: Dowa.

Type material studied

(5 exs.) Laccophilus trilineola . Holotype: female: "P.J. vd Kellen, Humpata, Afr. trop. / Laccophilus trilineola sp. n. type Régb. / trilineola sp. n. Régimb. / type" (RMNH).

Laccophilus simulator : Holotype, male: "Type / Nyasaland, stream 6 miles N of R. Mtiti 1.10. 1948 / Laccophilus simulator sp. n. Det. J. Omer-Cooper" (BMNH; two specimens on same pin but as holotype is clearly stated as male it is evident that specimen upper on pin must be the holotype). - Paratypes: Same data as holotype and pinned with it (1 ex. female BMNH); "Nyasaland stream, 6 miles N R. Mtiti 2.10. 1948 / Paratype / Paratype / Laccophilus simulator O-C. J. Omer-Cooper" (1 ex. IRSNB). One additional paratype labelled "Nyasaland stream? N of R. Mtiti 10. 1948 / Laccophilus simulator sp. n. J. Omer-Cooper det" belongs to Laccophilus adspersus Boheman.

Additional material studied

(1 ex.). Zaire: "Dilolo VIII-IX-1931 G.F. de Witte" (1 ex. OLML; habitus in Fig. 434).

Comments on synonymy.

The holotypes of Laccophilus trilineola and Laccophilus simulator have been examined and compared. The holotype of Laccophilus trilineola is a female and it is a unique specimen which makes study of male genitalia impossible. Both taxa, however, exhibit peculiar colour pattern on elytra (three longitudinal pale areas at base), which lack in other African species. Moreover, shape of female apical ventrite is also characteristic and similar in both taxa. Accordingly, the two taxa are considered conspecific. Laccophilus trilineola , being the older name is the valid name of this species.

Diagnosis.

Laccophilus trilineola is characterized by elytral colour pattern, peculiar female apical ventrite and uniquely shaped penis; penis in lateral aspect quite long, medium robust and medially bent; extreme apex peculiar with external end, expanded to form a sharp extension.

Description.

Body length 4.0-4.5 mm, width 2.1-2.5 mm. Dorsal, colour pattern as in Fig. 434.

Head: Pale ferrugineous, posteriorly only slightly darker. Submat, finely microsculptured. Reticulation double. Large meshes in part indistinct. When discernible they may contain 2-6 small meshes. Impunctate, except at eyes where irregular, fine punctures discernible. Areas of punctures extend towards middle of head.

Pronotum: Pale ferrugineous. Medially slightly darker than laterally. Rather shiny to submat although finely microsculptured. Reticulation double: Large meshes contain 2-6 small meshes. Finer reticulation laterally, in part indistinct. At margins with scattered very fine punctures; at posterior margin punctures almost absent; a few very fine punctures may, however, be discerned.

Elytra: Pale ferrugineous, with dense ferrugineous to dark ferrugineous irrorations. At base with three, slightly irregular, longitudinally extended, pale areas (Fig. 434). Slightly mat, finely microsculptured. Reticulation at least in frontal part double; posteriorly double reticulation is indistinct or absent. Scattered, very fine punctures may be discerned. In part punctures absent.

Ventral aspect: Pale ferrugineous to ferrugineous; no distinct colour pattern formed. Rather shiny to submat, finely and partly indistinctly microsculptured. Finely and sparsely striated; distinct striae only discerned on two basal ventrites. Almost impunctate. Prosternal process slender; apex extended and pointed. Apical ventrite asymmetric with sharp knob on one side (Fig. 87).

Legs: Protarsus slightly enlarged; provided with suckers.

Male genitalia: Penis in lateral aspect quite long, medium robust and external outline medially bent; extreme apex peculiar with external end, expanded to a sharp extension (Fig. 277).

Female: Protarsus slender. Apical ventrite (Fig. 88).

Distribution.

Zaire, Angola, Malawi (Fig. 552).

Collecting circumstances.

According to Omer-Cooper (1958b) the species has been collected in a stream with some pools full of decaying matter. Furthermore it was collected in a sluggish stream with patches of reeds and water weeds, and the bottom with fine algal growth. Also found in a clear river with water lilies, reed beds and swamp patches.