Ebenacobius costalis ( Fåhraeus, 1844 ) Haran & Benoit & Procheş & Kergoat, 2022

Haran, Julien, Benoit, Laure, Procheş, Şerban & Kergoat, Gael J., 2022, Ebenacobius Haran, a new southern African genus of flower weevils (Coleoptera: Curculioninae: Derelomini) associated with dicotyledonous plants, European Journal of Taxonomy 818 (1), pp. 1-54 : 23-26

Ebenacobius costalis ( Fåhraeus, 1844) gen. et comb. nov.

Figs 1E, I , 2E, 4I, 6E

Derelomus costalis Fåhraeus, 1844: 93 .

Derelomus rugosicollis Hesse, 1929: 530 . Syn. nov.

Differential diagnosis

Ebenacobius costalis gen. et comb. nov. can be distinguished from other species of the genus by the combination of basal ⅓ of first stria with a single row of at least slightly misaligned punctures ( Fig. 1E ) and by the rostrum moderately downcurved and only slightly longer than prothorax (1.1 ×) in lateral view ( Fig. 4I ).

Type material

Lectotype of Derelomus costalis Fåhraeus, 1844 (here designated) REPUBLIC OF SOUTH AFRICA • “ ♂ ” “ Cap. B. Spei. [ REPUBLIC OF SOUTH AFRICA, Western Cape Province]” “Drege” “3758. E91+” “Lectotype ♂; Derelomus . costalis ; Fåhraeus, 1844; Haran Des. 2022” “ Ebenacobius ; costalis ; ( Fåhraeus, 1844); Haran 2022”; NHRS.

Lectotype of Derelomus rugosicollis Hesse, 1929 (here designated) REPUBLIC OF SOUTH AFRICA • 1 ♂; “ Mfongosi; Zululand [REPUBLIC OF SOUTH AFRICA, KwaZulu-Natal Province]” “Zululand; Mfongosi; Apr 1923; W E Jones ” “ Derelomus ; rugosicollis ; Types Hesse” “Type [red label]” “Type; SAM/Ent; 4037 [red label]” “Lectotype ♂; Derelomus ; rugosicollis ; Hesse, 1929; Haran Des. 2022” “ Ebenacobius ; costalis ; ( Fåhraeus, 1844); Haran 2022”; SAMC.

Paralectotype of Derelomus costalis Fåhraeus, 1844 REPUBLIC OF SOUTH AFRICA • 1 ♀; same collection data as for lectotype of Derelomus rugosicollis excluding red type label; “Paralectotype ♀; Derelomus ; rugosicollis ; Hesse, 1929; Haran Des. 2022” “ Ebenacobius ; costalis ; ( Fåhraeus, 1844); Haran 2022”; SAMC .

Other material examined

REPUBLIC OF SOUTH AFRICA – Eastern Cape Province • 1 ♀; Kirkwood; 33°22′48.0″ S, 25°27′36.0″ E; 15 Jul. 2019; J. Haran leg.; on yellow Asteraceae ; JHAR02390_0101 ; CBGP • 1 ♂, 1 ♀; Alexandria Forest Station ; 33°43′ S, 26°23′ E; 3 Dec. 1987; Endrödy-Younga leg.; general collection; E-Y: 2549; TMSA • 1 ♀; Little Karoo , Baviaanskloof ; 33°39′ S, 24°31′ E; 6 Dec. 1995; C.L. Bellamy leg.; beating; E-Y: 3172; TMSA . – Kwazulu-Natal Province • 2 ♂♂; Pongolapoort; 27°25′15.7″ S, 31°55′10.3″ E; Oct. 2009; Ş. Procheş leg.; on Schotia brachypetala (Fabaceae) ; JHAR04161-62 ; CBGP. – Western Cape Province • 1 ♀; Plettenberg Bay ; 34°03′ S, 23°23′ E; 13 Feb. 1990; V.M. Uys leg.; SANC • 4 ♀♀; CT [Cape Town]; Nov. 1900; CleDoux leg.; acc67769; USNM.

Redescription

Male

BODY LENGTH. 3.0– 3.2 mm.

COLOUR. Body integument pale brown, head reddish-brown, prothorax with two large dark-brown areas on each side on the median line, elytra generally with a dense network of transverse dark shades on basal ⅔, sometimes reduced to transverse band on apical ⅔ or absent; dorsum (prothorax + elytra) with minute recumbent setae, not contiguous.

HEAD. Rostrum 1.1 × longer than prothorax in lateral view, moderately downcurved, slightly more near base; underside with row of setae, almost as long as 2 nd segment of funicle, integument forming small tubercle before apex; in dorsal view covered with recumbent non-contiguous setae; antennae inserted at ⅔ of length; head capsule coarsely punctate in dorsal view, with non-contiguous setae, setae slightly longer near dorsal margin on eyes; eyes convex, exceeding the lateral curve of head capsule in dorsal view; antennal funicle with segment 1 elongate, 1.5 × longer than wide, as long as 2–4, 3–7 wider than long.

PROTHORAX. Wider than long (W:L ratio: 1.3), widest near base, narrower there than elytra at humeral angles; sides subparallel in basal ¾, slightly and regularly converging apicad; apical constriction as long as width of funicle at apex; integument densely punctate, space between punctures smooth and shiny, narrower than or equal to diameter of punctures; setae in each puncture very short, recumbent, not exceeding in length the diameter of punctures; prosternal process reduced forming a small tubercle between the procoxae.

ELYTRA. Sides slightly convex, widest near middle of length (W:L ratio: 0.68); humeri raised; apex jointly rounded; striae made of one row of more or less misaligned punctures, at least misaligned on basal ⅓ of stria 1, narrower than interstriae; interstriae flat, 1-3-5 convex apically, 9 entirely convex; scutellar shield rounded, glabrous.

ABDOMEN. Underside covered with small non-contiguous whitish setae.

LEGS. Profemora strongly thickened near middle of length; protibiae with external margin straight, meso- and metatibiae curved outward in apical half; tibiae armed with small apical mucro; claws simple.

TERMINALIA. Body of penis elongate (W:L ratio: 0.32), as long as apodemes, sides slightly bisinuate in dorsal view, widest near apical ⅓, rounded and converging in apical ⅓, apex acuminate; in lateral view curvature stronger in basal ⅓, almost straight in apical ⅔, width slightly expanding apicad in basal ⅔ ( Fig. 6E ).

Sexual dimorphism

Females can be distinguished from males by their rostrum which is narrower and distinctly longer, 1.3 × longer than prothorax in lateral view (1.1 in ♂♂).

Remarks

In the collection housed at NHRS, a male specimen with the labels “Cap. B. Spei.” and “Drège” and corresponding to the description of Derelomus costalis in all respects was located. This specimen is the unique individual available and the description does not refer to a specific holotype, it is therefore here designated as the lectotype of Derelomus costalis Fåhraeus, 1844 and was labeled accordingly. In the collections housed at SAMC, a male specimen with the labels “Mfongosi; Zululand” and “ Derelomus ; rugosicollis ; Types; Hesse [hand written]” was identified. The description only refers to an undetermined number of males and females forming the type series. In the absence of a specific holotype designated for this species, the male specimen reported above is here designated as the lectotype for Derelomus rugosicollis Hesse, 1929 and was labeled accordingly.A detailed examination of the external and internal morphology of this specimen revealed no differences with the lectotype of Derelomus costalis . The name Derelomus rugosicollis is therefore a junior synonym of Derelomus costalis . It should be noted that the lectotypes of both D. costalis and D. rugosicollis are young ill-sclerotized specimens and that their uniformly pale colour is not representative of the colour pattern of the species. A redescription of this species is provided to account for the patterns found on fully sclerotized specimens of this species. In some specimens from the western Cape and Kwazulu-Natal Provinces of the Republic of South Africa, striae 9 are not erased in basal 1/6, but subcontiguous or merged with striae of 10.

Life history

The host plant of E. costalis gen. et comb. nov. is unknown, adults have been sporadically collected on flowers of Asteraceae and Fabaceae , which are probably only used as shelters by this species. Adults were collected in February, July, October, November and December.

Distribution

Republic of South Africa (Eastern Cape, Kwazulu-Natal and Western Cape Provinces).

Figures

Fig. 1(see preceding page). A–M. Details of morphology and measurements of Ebenacobius Haran gen. nov. and Derelomus Schoenherr, 1825. A. Ebenacobius rhodesianus (Hesse, 1929) gen. et comb. nov. in dorsal view, with the white arrows showing where the measurements of width (w) and length (L) are made for the prothorax (top) and elytra (bottom). Black arrow showing the narrowing of prothorax near apical margin. B. Head in lateral view of E. rhodesianus with white arrow showing the groove on forehead and the black arrow showing the convexity of the eyes, exceeding the lateral curve of head. C. Head and apex of prothorax in dorsal view of Derelomus chamaeropsis Fabricius, 1798 with the white arrow showing flat forehead, lacking groove and black arrow showing the constriction on the prothorax near apical margin. D. Detail of the top-left part of the right elytron in E. rhodesianus showing the white scales on interstriae and with the well aligned punctures at base of stria 1 highlighted in white. E. Detail of the top-left part of the right elytron in E. costalis (Fåhraeus, 1844) gen. et comb. nov. showing the setae on interstriae and with the misaligned punctures at base of stria 1 highlighted in white. F. Protibia of males of E. rhodesianus, showing the apical acute mucro and the ante-apical brush of setae. G. Head and prothorax of E. rhodesianus in lateral view with the arrows showing where measurements of rostrum and prothorax length are made. H. Right maxilla of E. rhodesianus in dorsal view. I. Penis of E. costalis in dorsal view showing were measurements are made for the body of penis (white arrows: width; top right black arrows: length) and the length of apodemes (bottom right black arrows).J. Stridulatory plate (tergite VII) in male of E. rhodesianus in dorsal view, with the cuticular tubercles used for stridulation highlighted in white. K–M. Female genitalia. K. Ovipositor in E. rhodesianus. L. Sternite VIII, same species. M. Spermatheca, same species. N. Right mandible, same species. O. Labial prementum, same species. A–O: not to scale.

Fig. 6 (part 1). A–I. Male genitalia of Ebenacobius Haran gen. nov., penis in dorsal (left) and lateral (right) view.A. E. curvisetis Haran gen. et sp. nov.B. E. rectirostrisHaran gen. et sp. nov.C. E. duplicatus Haran gen. et sp. nov. D. E. grobbelaarae Haran gen. et sp. nov. E. E. costalis (Fåhraeus, 1844) gen. et comb. nov. F. E. thoracicus Haran gen. et sp. nov. G. E. xhosa Haran gen. et sp. nov. H. E. san Haran gen. et sp. nov. I. E. kuscheli Haran gen. et sp. nov. A–I = not to scale.

Fig. 4. A–J. Habitus of males of Ebenacobius Haran gen. nov. in lateral view (part 1). A. E. curvisetis Haran gen. et sp. nov. B. E. thoracicus Haran gen. et sp. nov. C. E. rectirostris Haran gen. et sp. nov. D. E. xhosa Haran gen. et sp. nov. E. E. duplicatus Haran gen. et sp. nov. F. E. san Haran gen. et sp. nov. G. E. grobbelaarae Haran gen. et sp. nov. H. E. kuscheli Haran gen. et sp. nov. I. E. costalis (Fåhraeus, 1844) gen. et comb. nov. J. E. mulanjensis Haran gen. et sp. nov. A–J = not to scale.