Lamiogethes socotranus, Audisio, 2012

Audisio, Paolo, 2012, A new species of Lamiogethes from Socotra Island (Coleoptera: Nitidulidae: Meligethinae), Acta Entomologica Musei Nationalis Pragae 52, pp. 241-248 : 243-246

Lamiogethes socotranus sp. nov.

( Figs. 1–5 )

Type material. HOLOTYPE: J ( NMPC), ‘ YEMEN, SOCOTRA Island, Hagher Mts. , Skant, N 12º34.557′, E 54º01.514′, V.Hula & J. Niedobová leg., 7-8.vi.2010, collected on Cephalocroton socotranus ’. PARATYPES: same data as holotype, 6 JJ, 3 ♀♀ ( NMPC, PACR, BMNH) ; YEMEN: Socotra Island, Homhil Protected area , N12º34′27″ E54º18′32″, 364 m a.s.l., 28-29.xi.2003. D. Král lgt, 1 ♀ ( NMPC) ; YEMEN: Socotra Island, Al Haghier Mts. , Wadi Madar, N12º33′20″ E54º00′40″, 1180-1230 m a.s.l., 12-14.xi.2010, J. Bezděk lgt, 1 ♀ ( NMPC) ; YEMEN: Socotra Island, Wadi Zirik , N12º29.584′ E53º59.475′, ca. 500 m a.s.l., 12.vi.2010, V. Hula & J. Niedobová lgt, 2 JJ, 1 ♀ ( NMPC, PACR) ; YEMEN: Socotra Island, Dixam plateau, Wadi Zeeriq, N12º31′08″ E53º59′09″, 750 m a.s.l., 3.xii.2003. D. Král lgt, 1 ♀ ( NMPC) ; YEMEN: Socotra Island, eastern part, Zemhon area , N12º20′58″ E54º06′39″, 270-300 m a.s.l., 16-17.vi.2010, V. Hula lgt, 1 J, 1 ♀ ( NMPC) .

Diagnosis. Small to medium-sized, almost glabrous dorsally, reddish-brown with yellowish legs and antennae ( Fig. 1 ), frequently with darker, blackish elytra and ventrites, similar to Lamiogethes leucasi ( Easton, 1960) from Central and Eastern Africa in general appearance, with differently toothed protibiae (these markedly similar in shape to the European Lamiogethes difficilis (Heer, 1841) : Fig. 5 ), and different male genitalia ( Figs. 2–3 ).

Description (male holotype). Body medium-sized, length: 2.3 mm; width: 1.2 mm, moderately elongate and convex ( Fig. 1 ); unicolorous reddish-brown, shining, almost glabrous dorsally, with peculiarly fine and barely distinct golden pubescence on head only, glabrous elsewhere (ventral pubescence fine and short, golden), frequently with darker, blackish elytra and ventrites.

Head with deep punctures nearly 1.5× as large as eye facets, separated by one diameter or less, surface between them smooth, shining; anterior margin of clypeus almost truncate, with lateral angles rather blunt ( Fig. 1 ).

Antennae yellowish, medium-sized, antennomere 3 slender, much narrower, but slightly shorter than antennomere 2; club small and symmetrical ( Fig. 1 ).

Thorax. Pronotum convex, transverse, 1.85× as wide as long, moderately arcuate at sides, broadest near posterior angles, more narrowed anteriorly, sides distinctly bordered and narrowly explanate; posterior angles slightly obtuse but distinct; posterior basal margin markedly sinuate on either side of scutellum; discal punctures deep, 1.5–2.0× as large as eye facets, absent in posterior angles, separated by one diameter or more, surface between them shining.

Scutellum medium-sized, sparsely punctate in anterior half, shining and almost inpunctate posteriorly.

Elytra long, 1.0× as long as wide, broadest at basal second fifth, ca. 1.15× as wide as pronotum; humeri moderately raised, humeral striae absent; punctures as deep and large as those on pronotum; spaces between punctures smooth and shining.

Thoracic ventrites with fine short golden pubescence. Prosternal antennal ridges strongly marked; prosternal process distinctly wider (ca. 1.5×) than antennal club, apex flatly rounded; punctures rather deep, ca.1.5× diameter of eye facet, separated by nearly one diameter; surface smooth. Mesoventrite with posterior edge straight. Metaventrite flatly convex, with punctures shallower, as large as or slightly larger than eye facets, separated by one diameter or more, surface smooth and shining; secondary sexual characters represented by distinct wide impression on posterior two thirds of male metaventrite (appearing flat and simple in females). Metaventral ‘axillary line’ simple.

Legs yellowish. Protibiae ( Figs 1 , 5 ) with outer edge serrate in distal half, with a series of 4–5 longer, rather sharp teeth; protarsi in both sexes short, narrow, much shorter than antennae, protarsal plate in males slightly narrower than antennal club ( Fig. 1 ), more narrow in females; meso- and metatibiae rather long ( Fig. 1 ), with arc-like outer edge, bearing a regular series of strong, sharp and heavily sclerotiozed spinules; tarsal claws simple, not toothed at base.

Ventrites. Last abdominal ventrites simple, without distinct secondary sexual characters (posterior edge in middle barely emarginate in males), in both sexes with deep and strongly marked arc-like impression on each side.

Tegmen ( Fig. 2 ) long, arcuately narrowed distad, distinctly setose at apex, apical excision deep and peculiarly narrow; aedeagus elongate ( Fig. 3 ), abruptly narrowed from distal third, and markedly pointed distad.

Female. Ovipositor yellowish, with rather blunt and slightly darker apex, bearing quite long styli inserted close to apex ( Fig. 4 ); ‘central point’ placed at distal three sevenths, without ventral spicule; transverse suture narrowly V-shaped, with arcuate base of gonocoxites.

Variation. The new species exhibits relatively strong variation in body colour (from unicolorous pale orange to orange-brown with blackish elytra and ventrites) and size (length: 1.8–2.4 mm; width: 0.95–1.25 mm).

Biology. Several specimens of the new species were collected on flowering shrubs of Cephalocroton socotranus Balf. f. ( Euphorbiaceae ), a Socotran endemic inhabiting subtropical dry shrublands in mountainous areas of the island. Euphorbiaceae are among the relatively few plant families colonized by Meligethinae larvae (larvae of a single unrelated genus in Central Africa were recently collected on inflorescences of Macaranga spp. , Euphorbiaceae ; P. AUDISIO, unpublished data), but Lamiogethes species appear to be all strictly associated with Lamiaceae . This occurrence of a Lamiogethes on a non-Lamiaceae host suggests that the hypothesis of a possible larval-host plant relationship of Lamiogethes socotranus sp. nov. with Cephalocroton Hochst. is rather unlikely, which is also supported by the low ratio of collected females to males. Combining the relatively close morphological relationships of the new species with L. leucasi ( Easton, 1960) and related species from Eastern and Central Africa, mostly associated with Leucas spp. ( Lamiaceae ; EASTON 1959, 1960; AUDISIO unpublished data), as well as the occurrence of seven Socotran endemics in this botanical genus ( Leucas flagellifolia (Balf.f.) Guerke, L. hagghierensis Al-Gifri & Cortés-Burns , L. kishenensis (Radcl.-Sm.) Sebald, L. penduliflora Al-Gifri & Cortés-Burns , L. samhaensis Cortés-Burns & A.G.Mill. , L. spiculifera (Balf.f.) Guerke, and L. virgata Balf. f.; SEBALD 1980; SCHEEN & ALBERT 2009), I suspect that at larval stages the new species could be associated with one of the above cited Leucas species. However, further more recent (June, 2012) field research on the island seems to confirm a regular association of adults of Lamiogethes socotranus sp. nov. with Cephalocroton socotranus (J. Hájek, pers. comm.). During the same recent expedition, some specimens of the new species were also found in flowers of Carphalea obovata (Balf. f.) Verdc. ( Rubiaceae ), but none was observed at the top of Haghier Mts., where Leucas hagghierensis was one of the dominant plants. These combined circumstances could then suggest that the hypothesis of a possible ecological shift of Lamiogethes socotranus sp. nov. on Cephalocroton should not be excluded. On the other hand, nothing is known about the larval host-plant relationships of the several southern Indian Lamiogethes related to the new Socotran species (see discussion below).

Etymology. The new species is named after its area of occurrence, i.e. Socotra Island.

Distribution. Lamiogethes socotranus sp. n. is only known from the above cited type localities on Socotra Island, Yemen.

Figures

Fig. 1. Lamiogethes socotranus sp. nov. 1 – habitus of a male paratype (Body length: 2.4 mm).

Figs.2–5.Lamiogethes socotranus sp. nov.2–3 – male genitalia (tegmen and median lobe of the aedeagus,dorsal view) of a male paratype; 4 – ovipositor of a female paratype; 5 – front tibia of a male paratype. Scale bar = 0.2 mm.