Paleosepharia truncata Laboissière, 1936

Rizki, Alia, Hazmi, I. R., Wagner, TH. & Idris, A. B., 2016, Redescription ofPaleosepharia trunctataLaboissiére, 1936, Type Species of the GenusPaleosephariaLaboissiére, 1936 (Coleoptera: Chrysomelidae: Galerucinae), The Coleopterists Bulletin 70 (2), pp. 395-398 : 395-398

Paleosepharia truncata Laboissière, 1936 ( Figs. 1–2 )

Paleosepharia truncata Laboissière 1936: 251

Holotype. Male, “Museum Paris, Cochinchine Pierre 1878/1443/78/Type/ Paleosepharia truncata m. v. Laboissière – Det.” ( MNHN) . Holotype by original designation. Paratypes: Five males, same data as holotype, but label “cotype” (cf. Fig. 1 ), 4 ex. MNHN , 1 ex. ZMUH .

Type Locality. Cochinchina ( Vietnam), 11°0′N / 107°0′E .

Redescription. Measurements: Total length 7.20–7.90 mm (mean 7.70 mm, n = 6). Head: Yellowish brown, with deep, small punctures. Labrum yellowish brown, mandible yellowish brown with apex black. Antennae with 11 antennomeres,

slender, extending to middle of elytra, yellowish brown. Antennomere 1 club-shaped, antennomere 2 shorter than 3, length ratio of 2:3 0.55–0.60 (mean 0.57); length ratio of 3:4 0.65–0.71 (0.67), antennomere 2 to terminal antennomere with very fine, yellow setae. Vertex covered with small punctures, yellow heart-shaped in the middle of vertex. Eyes large (diameter 0.73), distance between antennal sockets 0.22 mm. Antennal socket diameter 0.27 mm. Thorax: Pronotum strongly bulged, posterior angles pointed ( Fig. 1B ), without transverse impression, yellowish brown, covered with small punctures. Pronotal width 2.15–2.55 mm (mean 2.48 mm), ratio length to width 0.58–0.63 (mean 0.60). Scutellum triangular, impunctate, yellowish brown. Procoxal cavities nearly closed. Elytral length 5.80–6.30 mm (mean 6.14 mm), maximum width of elytra 3.20–3.80 mm (mean 3.60 mm), ratio of maximum width of elytra to elytral length 0.57–0.63 (mean 0.61). Elytra with longitudinal impression behind scutellum ( Fig. 1B ). Legs yellowish brown with dense setae. Third femur and basal coxa partly black. Abdomen: Yellowish brown; 7th sternite (= 5th ventrite) with 2 deep lateral incisions ( Fig. 2 ), 8 th tergite with 2 strong, curved hooks ( Fig. 2 ). Male genitalia: Median lobe gradually narrowing apically, narrowing towards apex. Tectum long, broad at base and tapered towards apex, with shallow incision. Two types of spiculae clearly visible (lateral and median), while ventral spiculae weakly sclerotized. Median spiculae consisting of 2 pairs of long and slender spiculae.

Diagnosis. Paleosepharia are medium-sized galerucines (total length of 7.20–7.90 mm) with strongly elongated basal metatarsomeres and yellowish brown head and pronotum. In comparison to other genera which are traditionally listed in the group of Monoleptites, specimens of this genus are on average larger than those of Arcastes Baly, 1865 (4.45–7.35 mm), Rubrarcastes Hazmi and Wagner, 2010 (5.60–7.60 mm), roughly the same size as those of Candezea , and significantly larger than species of Monolepta (4.80–6.20 mm), Neolepta Jacoby, 1884 (4.85–5.75 mm), and Orthoneolepta Hazmi and Wagner, 2013 (4.50– 5.75 mm). Species of Paraneolepta Hazmi and Wagner, 2013 (6.65–10.10 mm), Nadrana Baly, 1865 (8.20–9.48 mm), and Ochralea Clark, 1865 (7.75–14.40 mm) are on average larger than species of Paleosepharia .

The pronotum of Paleosepharia is comparatively broad and strongly bulged, with pointed posterior angles (pronotal length to width ratio 0.58–0.63) and without a transverse depression, similar to most genera listed in the Monoleptites with the exception of Orthoneolepta and Paraneolepta that have transverse depressions on the pronotum. The second antennomere is much shorter than the third in Paleosepharia (length ratio of second to third antennomeres 0.55–0.60), about the same range as in Arcastes (0.50–0.57) and some species up to now placed in Candezea , but very different to Monolepta (0.83–1.00) and Ochralea (0.67–0.90) of which the second and third antennomere are roughly the same length.

Males of Paleosepharia are characterized by subscutellar bulged or incised ridges on the elytra. This sexually dimorphic pattern is often encountered in many Afrotropical species of Candezea , Afrocrania Hincks, 1949 , and Afrocandezea Scherz and Wagner, 2002 . From these taxa, Paleosepharia can be easily differentiated by two distinct, moveable spines formed by the eighth tergite ( Fig. 2 ). These spines are most likely important for an effective copulation. In other species of Paleosepharia , this structure is more fork-shaped (A. Rizki, personal obervation). This character is found only in this genus. The tectum of Paleosepharia is long, gradually narrowing apically at the base, and becomes narrowed towards the apex. The structure and arrangement of the endophallic spiculae are simpler compared to the other genera. Paleosepharia has two pairs of strongly sclerotized spiculae (lateral and median), while the ventral spiculae are weakly sclerotized. The median spiculae consist of long, slender spikes. Monolepta has three distinct types of spiculae on the endophallus: ventral endophallic spiculae are small and comb-like; median spiculae are long, slender, and straight; lateral spiculae are slender, with a small, claw-like spine medially ( Wagner 2007).

Distribution. Vietnam, Thailand, and Laos.

Figures

Fig. 1. Paleosepharia truncata. a) Holotype with labels, b) Close-up image of holotype.

Fig. 2. Paleosepharia truncata. a) Sixth and seventh sternite (= fourth and fifth ventrite) and eighth tergite with two strong, curved hooks of the male in ventral (left) and caudal (right) views, b) Median lobe, in lateral (left), dorsal (middle) and ventral (right, without endophallic spiculae) view. Scale bars = 1 mm.