Lethaeus ater (Thunberg, 1822) Thunberg, 1822

Kondorosy, Előd, Rédei, Dávid & Mejlon, Hans, 2014, Taxonomic corrections to species of Rhyparochromidae (Hemiptera: Heteroptera) described by Carl Peter Thunberg, Zootaxa 3838 (5), pp. 567-574 : 568-569

Lethaeus ater (Thunberg, 1822) , new combination

( Figs. 1–3 )

Lygaeus ater Thunberg, 1822b: 3 . Syntype (s): Capensis [= South Africa]; depository not stated.

References. Stål (1855): 347 (synonymy); Slater (1964): 1192 (identity, synonymy).

Type material examined. Lectotype (present designation) ♂ ( Figs. 1–2 ): “Uppsala Univ. Zool. Mus . / Thunbergsaml. nr. 18550 / Lygaeus ater / Cap. TYP” [red, printed]; “ LECTOTYPUS / Lygaeus ater / Thunberg, 1822 / desig. Kondorosy, 2013” [with red frame, printed]; “ ater . / Cap. 19” [handwritten, pinned in the drawer next to the specimen ( Fig. 3 )]; deposited in UPSZ. Pinned; left fore wing, left antenna and segments II–IV of right antenna, and all legs distad of coxae with the exception of right fore leg, missing; body broken between pro- and mesothorax by pin.

Redescription. Colour. Ground colour of body and appendages fuscous brown (antennal segments II–IV as well as mid and hind legs missing in the single examined specimen); head, anterior part of pronotum, scutellum and posterior half of abdominal tergum (segments V–VII) almost black except apical projection of tergite VII; membrane, labial segments II–III, fore tibia and metepimeron, brown; veins of corium with tiny yellow streaks.

Structure. Body glabrous except abdomen and extremities; slightly shining, almost opaque. Head and anterior half of pronotum with fine punctation, remaining parts of dorsum with stronger punctures.

Head pentagonal, antennae inserted far from eyes, lateral outlines of antenniferous tubercles parallel in dorsal view. Ocelli situated relatively close to eyes, eyes reaching anterior margin of pronotum. Antennal segment I surpassing apex of clypeus by about half of its length. Apex of labium reaching about base of mid coxae (surpassing middle of mesosternum).

Thorax. Pronotum convex, without any trace of transverse furrow or median carina, anterior margin concave, posterior margin almost straight, laterally convex; lateral margin moderately broadly laminate. Scutellum triangular, flat, without carinae. Hemelytra abbreviated ( Fig. 1 ), reaching only base of tergite VII; clavus and corium immovably fused (claval furrow weakly developed), apex of corium broadly rounded, membranal margin of corium straight, oblique; clavus with four irregular rows of punctures; membrane reduced to a narrow stripe. Metathoracic scent gland ostiole close to coxae, slit-like, provided with short, auriculate peritreme curved posteriorly; evaporatorium relatively small, occupying only about medial half of metapleuron, extending to the posterior supracoxal lobe of the mesopleuron. Fore femur slightly thickened, more slender than width of vertex, ventral surface with some long setae and four or five very short spines apically; fore tibia straight, unarmed; first segment of fore tarsus about as long as combined lengths of the remaining two segments; mid and hind legs absent in the single examined specimen.

Abdomen with suture between sternites IV and V curved anteriorly and ending in a trichobothrial furrow as typical in Rhyparochromidae . Trichobothria of sternum V rectilinear, anterior and middle trichobothria close to each other on anterior part of sterna, posterior one situated posteriad of spiracle. All spiracles ventral. Connexivum upturned, posterolateral angle of connexival segments VII broadly, obtusely angulate.

Measurements (in mm): body length 8.6, length of head 1.15, greatest width across eyes 1.55, width immediately frontad of eyes 1.15, interocular distance 1.0, length of pronotum 2.0, humeral width 3.05, length of scutellum 1.6.

Discussion. A single male ( Fig. 1–2 ) is present in Thunberg’s collection in UPSZ. The brief original description of Lygaeus ater fits well with this specimen, except the fore wings which are not completely devoid of spots (“immaculatus hemelytris opacis”). Based on the ancient handwritten label pinned next to the specimen ( Fig. 3 ) it is considered as part of the original type series and it is hereby designated as a lectotype.

Stål (1855) synonymized Lygaeus ater with Rhyparochromus echii (Panzer, 1799) , now a junior synonym of Aellopus atratus ( Goeze, 1778) ; the same synonymy was cited by Slater (1964) and Péricart (2001). Reexamination of the type material revealed that the act of Stål (1855) was erroneous, Lygaeus ater is not conspecific with A. atratus . The spiracles and trichobothria undoubtedly indicate that it belongs to the tribe Lethaeini.

Since all members of Lethaeus Dallas, 1852 and related genera are known from macropterous morphs only, brachyptery is an unusual character of this species. Several characters, particularly the shape of the head, the absence of a pronotal collar, the absence of anterolateral setae of the pronotum, as well as the hemelytral colour, and the armature of the fore femora, still suggest that in spite of the reduced wings it belongs to Lethaeus . As a consequence, the new combination Lethaeus ater (Thunberg, 1822) , comb. nov., is hereby proposed. The species is apparently not conspecific with any other described species of Lethaeus .

Lethaeus barberi Slater, 1964 , another brachypterous species of Lethaeini from South Africa, based on the reexamination of its holotype deposited in MZLU certainly does not belong to this genus as its pronotum is provided with a rather narrow collar and anterolateral setae. Currently it is not possible to place this species with confidence in any existing genus.

Figures

FIGURES 1 – 7. Lectotypes of three of Thunberg’s species and selected relevant labels. 1 – 3, Lygaeus ater Thunberg, 1822; 4 – 5, Lygaeus biguttatus Thunberg, 1822; 6 – 7, Cimex caffer Thunberg, 1784. Scales in mm; labels not to scale.