Namibeletica Bologna, 2018

Bologna, Marco A., Amore, Valentina & Pitzalis, Monica, 2018, Meloidae of Namibia (Coleoptera): taxonomy and faunistics with biogeographic and ecological notes, Zootaxa 4373 (1), pp. 1-141 : 11-13

Namibeletica Bologna gen. n.

Type species. Cantharis elegantula Péringuey, 1909 , fixed by present designation.

Diagnosis. A very distinct eleticine blister beetles, endemic to Namib and Namaqualand deserts, with unclear phylogenetic relationships (see remarks), tentatively referred to the tribe Eleticini , because of the lacking of male elytral pit at apex, the male tergum VIII extensively sclerotized, mesepisterna broadly truncate, widely separate, without wide modified fore portions delimited by distinctly elevated ridge, differently than in other members of the tribe.

In common with Eletica Dejean, 1834 (which belongs to the Palaetropical subtribe Eleticina sensu Selander 1966) the new genus has bilobed tarsomeres I–IV (I–III on hind legs), stout and short gonocoxal plate, robust and short gonoforceps apically curved forwards, aedeagus with two apical hooks directed posteriad. Differs from Eletica primarily because of frons not swollen, eye greatly shorter than frontal interocular distance, elytra densely setate and without costae (raised venations), ventral blade of claws microsetate but not fringed at base, male sternum VIII not recessed in segment VII, sclerotized and undivided gonoforceps fused also dorsally.

In common with Eospasta Selander, 1966 and Serrospasta Selander, 1966 (both belonging to the Neotropical subtribe Eospastina sensu Selander 1966) the new genus has the frons not swollen between eyes, elytra setate and without ribbings, ventral blade of claws microsetate but not fringed at base, VIII male sternum well exposed, sclerotized and undivided. Namibeletica differs from both genera primarily because of eye smaller, male antennomeres subtrapezoidal but not distinctly subserrate or serrate, mesosternum anteriorly not angulate, protarsomeres bilobed (this condition is present in Serrospasta ), male phallobase stout and short, gonoforceps stout and short apically curved, rather than slender and straight.

Description. Body black, but pronotum and femurs orange, only partially black, elytra almost completely ochre with black apex or completely black; body setation white. Body length 5–12.5 mm.

Head transverse, temples parallel in male, slightly widened posteriorly in female, frons not swollen between antennal base, depressed on both sides close to antennal base; surface with punctures more or less scattered and scarcely deep, setation more or less dense; eye length ca half as long as temple and less than half the inter-ocular diameter; clypeus subtrapeizoidal, fore third smooth; labrum widely emarginated in front; mandibles robust, curved on apical third, pointed at apex; maxillary palpi with four palpomeres not modified; 11 antennomeres ( Fig. 7F ), slightly slender and longer in male, antennomere I subcylindrical, slightly widened in apical half, about twice as long as II, II very short and subglobose, III–X subtrapeizoidal, particularly V–IX, more asymmetrical in male, last one subcylindrical in basal half, slightly widening from base, suddenly narrowing in apical half, not depressed.

Pronotum unsetate, shiny, about as long as head, sub-pentagonal, slightly longer than wide, fore depression wide and deep, extended obliquely on sides, longitudinal depression extended from the middle to the base, widening at base; whole base and sides distinctly depressed; prosternum transverse, depressed in front. Visible portion of mesonotum (scutellum) sub-squared at apex more or less densely covered by setae; mesosternum transverse and narrow, scarcely angulate in front, triangular posteriorly; mesepisterna broadly truncate, widely separate, without wide modified fore portions delimited by strongly elevated ridge. Metasternum with unsetate longitudinal middle area. Legs black, but femurs orange except on apex and basal third more or less extensively black; protibiae almost straight externally, at apex scarcely more expanded in female, with two elongate and pointed spurs in both sexes; meso- and metatibial spurs both pointed and slender; protarsomeres II–IV bilobed ( Fig. 7E ), meso- and metarsomeres I–IV and I–III bilobed but less widened and protarsomeres. Elytra setate, only with track of low and unraised venations, lacking of male elytral pit at apex.

Ventrite VII widely emarginated in male, convex at middle and concave on both sides in female; male sternum VIII well exposed, sclerotized and undivided; male sternum VIII at base emarginated, depressed on sides at middle, deeply emarginated on posterior margin; female sternum VIII sclerotized on the basal and apical third, widely membranous in the middle; male tergum VIII extensively sclerotized, undivided; IX male sternum (spiculum gastrale) ( Fig. 7D ) T-shaped, robust and well sclerotized. Male genitalia ( Figs. 7 A-C) with stout and short gonocoxal plate, robust and short gonoforceps apically curved forwards, narrowed and almost pointed, dorsally fused in middle; aedeagus with two apical hooks directed posteriad, slerotized apical portion of ejaculatory ductus forming a wide sub-cordiform structure.

Etymology. The name of the new genus refers to Namibia , where the genus is mainly distributed, and to Eletica , the type genus of the tribe Eleticini to which we tentatively refer the new genus. Feminine genus.

Remarks. As pointed out by Bologna & Pinto (2002), “ Cantharis ” elegantula Péringuey, 1909 belongs to a new genus of the subfamily Eleticinae . The new genus includes another species from the southern Angola, which is described here.

The new genus actually shows a combination of features of both Eleticini lineages (sensu Selander 1966), the Palaeotropical subtribe Eleticina, which includes the genus Eletica , and the Neotropical subtribe Eospastina, which includes Eospasta and Serrospasta . The value of these subtribes need confirmation and is not discussed here. The first lineage is marginally spread also in southern Africa, in particular in north-eastern South Africa and in northern Namibia , with a few species of Eletica . Namibeletica is possibly associated to an undescribed genus from Yemen (Bologna & Geisthardt in preparation).

The shape of male genitalia is similar to that of Eletica and greatly differs from that of the Neotropical genera; protarsomeres I–IV are bilobed as in Eletica and Serrospasta , but this character is not distinctive of one lineage. The claw setation differs from Eletica because of the ventral blade of claws microsetate but not fringed at base, as in Eospasta and Serrospasta ; elytra are setate and without visible raised costae as the last two genera, and the frons is not swollen between eyes. The well exposed VIII male sternum, which is sclerotized and undivided and the setate elytra are similar to Eospasta and Serrospasta , but Namibeletica differs from both by the eye smaller, with fore margin almost straight; mesepisterna are anteriorly only slightly angulate, as in Eletica , but without wide modified fore portion.

The two species belonging to the new genus Namibeletica can be distinguished by the following key:

1 Elytra brown-gray, fuscate at apex; pronotum orange with the following black colouration: a middle fore stripe, two basal lateral spots, and rarely two additional fore lateral spots ( Fig. 1H ); dorsal depressions on sides and at base of pronotum deep; head setae dense and robust. Western South Africa, southwestern Namibia ................. elegantula ( Péringuey, 1909)

- Elytra black, pronotum orange with the following black colouration: a middle fore stripe and rarely two additional fore lateral spots ( Fig. 1G ); dorsal depressions on sides and at base of pronotum shallow; head setae dense but finer. Southwestern Angola................................................................................. angolana Bologna sp.n.

Figures

FIGURE 1. A. Iselma deserticola; B. Iselma hobohmi; C. Iselma penrithae; D. Iselma brunneipes. E. Iselma piscatrix; F. Eletica luteosignata. G. Namibeletica angolana; H. Namibeletica elegantula; I. Afrolytta namaqua; J. Afrolytta amoena; K. Afrolytta carneola; L. Australytta maraisi; M. Australytta rubrolineata; N. Australytta szekessyi; O. Australytta vellicata; P. Lydomorphus chalybaeus; Q. Lydomorphus mimus; R. Lydomorphus bisignatus; S. Lydomorphus strangulatus; T. Lydomorphus karibibensis; U. Lydomorphus thoracicus; V. Lydomorphus tibialis; W. Lydomorphus bifoveiceps; X. Dilatilydus optatus; Y. Desertilydus mesembryanthemi.

FIGURE 7. Namibeletica elegantula: male genitalia in ventral (A), lateral (B) and dorsal view (C); spiculum gastrale (D); male protibia and protarsomeres (E); male antenna (F). Bar = 1 mm.