Psammoecus nyakabuyensis, Karner, 2014

Karner, Michael, 2014, Three new species and new records of African Psammoecus Latreille (Coleoptera, Silvanidae), European Journal of Taxonomy 89, pp. 1-18 : 3-6

Psammoecus nyakabuyensis sp. nov.

Fig. 2A–G

urn:lsid:zoobank.org:act:FEA38F3A-722B-45B0-B336-1C885FDB7262

Diagnosis

The following combination of character states is diagnostic for this species: 1 st antennomere 2.1 times as long as 2 nd antennomere; maximum pronotal width near middle; lateral margins of pronotum with distinct, triangular teeth with wide bases, anterior angle of pronotum with distinct denticle; elytral striae narrower than interstices; interstices of lateral elytral striae with very small tubercles; median lobe of aedeagus wide, abruptly narrowed towards apex; parameres distinctly separated from basal piece.

Differential diagnosis

Psammoecus nyakabuyensis sp. nov. resembles P. luchti Karner, 2012 and can be distinguished by its narrower elytral striae; it differs from P. luchti and all other African Psammoecus also by the shape of the male genitalia.

Etymology

The specific epithet is derived from the name of the locality where the type material was collected.

Material examined

Holotype

♂ ‘Afrika RUANDA | Pref. Cyangugu | Umg. Nyakabuye | 17.2.1985 [17 Feb. 1985] | leg. H. Mühle’ ( SMF).

Paratypes

2 ♀♀ ‘Afrika RUANDA | Pref. Cyangugu | Umg. Nyakabuye | 16.10.1984 [16 Oct. 1984] | leg. H. Mühle’ ( MKF). 1 ♂ ‘Afrika/ Rwanda | Bez. Cyangugu | Urw.v.Nyakabuye | 1700–1900 m | leg.V.u.C. Brachat | 14.– 27.2.1985 [14–27 Feb. 1985]’ ( MKF) .

Description of holotype

BODY (as in Fig. 2A ). Oval, castaneous, total length 3.05 mm. Elytra with transverse, dark brown maculae near middle. Antennomeres 8–10 dark brown, 11 bright testaceous.

HEAD (as in Fig. 2B ). Eyes large, prominent; temples distinctly narrowed immediately behind eyes, temple angle 65°; head width 0.79 mm, length 0.46 mm. Puncturation on vertex coarse, punctures about 1.25 times as large as an eye facet diameter, contiguous laterally, well separated medially; pubescence composed of short, semierect setae, directed anteriorly; microsculpture absent. Longitudinal impressions on vertex short and shallow, curved outwardly, attaining 1/5 of eyes. Eyes 0.21 mm long, distance of inner margins 0.50 mm. Temples immediately narrowed behind eyes, slightly curved. Antennae comparatively stout, 1.44 mm long; antennomere proportions: 2.5: 1.2: 1.3: 1.3: 1.3: 1.3: 1.0: 1.0: 1.0: 1.0: 2.0 ( Fig. 2D ).

PRONOTUM (as in Fig. 2C ). Wider than head, lateral margins strongly curved, widest at middle, surface slightly impressed near posterior angles and basis; width 0.90 mm, length 0.64 mm. Anterior angles with small denticles; lateral margins with four wide teeth; T I very small, only slightly larger than anterior denticles, T II about twice as big as T I, T III and T IV of same size, about twice as big as T II; posterior angle with small denticle, located in the middle between T IV and posterior margin. Puncturation and pubescence on pronotal disk as on vertex; punctures more sparse near posterior angles and basis. Microsculpture absent.

ELYTRA. Oval, widest at middle, length 2.00 mm, combined width 1.35 mm. Rows of punctures on disc somewhat narrower than interstices; pubescence composed of short semierect setae, strial and interstrial setae of identical length; microsculpture absent.

MALE GENITALIA (as in Fig. 2E–G ). Parameres wide, moderately narrowed towards apex, bearing numerous long setae near mesal face of basis, shorter setae on ventral edge, and a very long and a short seta at apex; in lateral view strongly narrowed near middle, and widened, somewhat spoon-shaped, towards apex. Median lobe wide, narrowed towards apex in a basally convex, apically concave curve to form a narrow, almost parallel-sided protrusion with blunt tip; S-curved towards apex in lateral view.

Variation

The paratypes vary in body length from 2.92 to 3.30 mm.

Remarks

Even though Psammoecus nyakabuyensis sp. nov. resembles P. luchti in general appearance, the structures of the male genitalia differ very much ( Fig. 3A–B shows the genitalia of P. luchti for comparison). A close relation of these two species is therefore very unlikely.

Figures

Fig. 2. Psammoecus nyakabuyensis sp. nov., holotype. A. Habitus. B. Head. C. Pronotum. D. Right antenna. E. Aedeagus, ventral view. F. Paramere, lateral view. G. Median lobe, lateral view. Scale lines: A = 1.0 mm, B–D = 0.5 mm, E–G = 0.2 mm.

Fig. 3. Psammoecus luchti Karner, 2012. A. Median lobe. B. Parameres. Scale lines = 0.2 mm.