Elaeidobius pilimargo Haran & Kuschel, 2020

Haran, Julien M., Beaudoin-Ollivier, Laurence, Benoit, Laure & Kuschel, Guillermo, 2020, Revision of the palm-pollinating weevil genus Elaeidobius Kuschel, 1952 (Curculionidae, Curculioninae, Derelomini) with descriptions of two new species, European Journal of Taxonomy 684, pp. 1-32 : 14-17

Elaeidobius pilimargo Haran & Kuschel sp. nov.

urn:lsid:zoobank.org:act:1FEB6463-7D76-49B5-91A1-F28ECAA2D0DB

Figs 1E , 3A , 4E

Etymology

The species name pilimargo is derived from ‘pilus’ for ‘hair’, and ‘margo’ for ‘margin’.

Material examined

Holotype

GHANA • “ GOLD COAST [ Ghana ]. Accra. 11.X.1920. Mrs W. H. Patterson ” “On Oil Palm flowers” “ Elaeidobius sp. indet. B. R.T. Thompson det. 2004” “ Holotype [red label]. Elaeidobius . pilimargo . Haran & Kuschel. Haran & Kuschel 2019”; NHMUK.

Paratypes

GHANA • 2 ♂♂; same collection data as for holotype; “ Paratype. Elaeidobius . pilimargo . Haran & Kuschel. Haran & Kuschel 2019”; NHMUK .

NIGERIA • 3 ♂♂; “ Nigeria. Ife, W State. 15.xii.1974. J.T. Medler coll.” “ Elaeidobius sp. indet. B. R.T. Thompson det. 2004” “ Paratype. Elaeidobius . pilimargo . Haran & Kuschel. Haran & Kuschel 2019”; NHMUK .

SENEGAL • 1 spec.; Dakar, Malika ; 4 Oct. 2017; J. Haran leg.; Elaeis guineensis ; JHAR00409_0201; CBGP .

Description (♂ ♀)

BODY LENGTH. 2.5–3.0 mm.

COLOUR. Yellow or reddish brown metasternum, antennal club in part darker; often prothorax and elytra with dark stripes or oblique bands; in male, elytra with long erect setae on margins and on suture but not on base of interstria 4.

HEAD. Strongly punctate, punctuation partly confluent towards frontal fovea; forehead in male with prominent carinae against eyes and depressed between them, in female with low or obsolescent carina and not depressed; rostrum in male as long as prothorax, in female 1.2–1.4 × longer, cylindrical, 5-carinate in basal ¾, median carina widening near antennal insertion, apical ¼ smooth and punctate, underside in male lacking erect hairs and postmental tubercle; antennae yellowish or reddish brown, insertion on rostrum median in male, antemedian in female; scape slightly curved, gradually thickening toward apex, first segment of funicle elongate, in male as long as segments 2–4, in females longer than segments 2–4, segment 2 longer than wide, 3 isodiametric, 4–7 transverse, gradually widening to width of club.

PROTHORAX. Sub-trapezoidal (w/l ratio: 1.46), converging in a straight or nearly straight line, deeply bisinuous at base, concavely curved at apex; apical collar at base with a transverse row of black dots; disc in lateral view nearly flat, with four impressions anteriorly, and a pair of large, deep foveae on either side of middle; integument with double punctuation, glabrous in appearance, with a very short pubescence mainly on sides at basal half; carina in lateral view obsolete or obsolescent towards base, weakly sinuous near apex, sharply carinate on collar.

ELYTRA. Widest near middle (w/l ratio: 0.70), in male not tectiform, base of interstriae 3–5 raised to a tumour or swelling, apical ¾ of suture darker, slightly raised with a row of erect setae, interstria 10 in male swollen, somewhat inflated bearing long upwardly curved erect setae, interstria 9 in female costate in basal ¾; striae as wide as width of interstriae or slightly narrower, gradually fading apicad; stria 9 absent basally, starting from near height of fore coxae; dark stripe on elytra generally present on interstria 6 in basal half and between middle of interstriae 3 or 4 to 8 before declivity.

LEGS. Integument pale yellow, mostly glabrous, with whitish suberect hairs in apical ¾ of tibiae and on tarsus; tibiae bisinuate on ventral side, with a small mucro apically; tarsi with first segment elongate, 0.7 as long as segments 2+3; segment 3 deeply bilobate; segment 4 elongate, slightly shorter than 1+2+3; claws free, not apendiculate.

ABDOMEN. Tergite 7 with about 14 plectral granules; ventrites with short suberect, scattered whitish hairs; in male ventrites 1 and 2 impressed in middle, without specific pilosity on margin on impression.

GENITALIA. Penis as long as last three ventrites; body 1.7 × longer than apodemes, symmetrical, more than 2 × longer than wide (w/l ratio: 0.40), parallel-sided, blunt at apex ( Fig. 4E ), with a pair of small median sclerites.

Life history

All the specimens collected recently were found on inflorescences of the oil palm, Elaeis guineensis (Arecaceae) (JH pers. obs.).

Distribution

Benin (Cotonou); Cameroon (Bota); Ghana (Aburi); Nigeria (Ife); Senegal (Malika-Dakar).

Remarks

Elaeidobius pilimargo sp. nov. is characterised by its elytral margins bearing long erect setae and presence of a swelling on base of interstria 4 without erect setae in males ( Fig. 5 J–K). The likely females examined are not part of the type series because their identity cannot be guaranteed based on morphology. Elaeidobius pilimargo sp. nov. is morphologically close to E. singularis . Both species show a genetic distance of 2.01% on COII (JHAR00409_0201, Senegal / JHAR00283_0101, Ghana). The sequencing of the COI gene for specimens of E. singularis failed repetitively, probably due to polymorphism in the primer sequences. Within the E. plagiatus species group, the COI sequence of E. pilimargo sp. nov. showed a genetic distance of 2.88% with E. piliventris sp. nov. (JHAR02182_0101).

Figures

Fig. 1. Habitus of males and females of species of Elaeidobius Kuschel, 1952. A. E. bilineatus (Hustache, 1924) comb. nov., Dakar, Senegal. B. E. spatulifer (Marshall, 1950) comb. nov., holotype, Thysville, Democratic Republic of Congo (MRAC). C. E. subvittatus (Faust, 1898), Dakar, Senegal. D. E. kamerunicus (Faust, 1898) comb. nov. (JHAR00209). E. E. pilimargo Haran & Kuschel sp. nov. (JHAR00409). F. E. piliventris Haran & Kuschel sp. nov. (JHAR02182). G. E. plagiatus (Fåhraeus, 1844) comb. nov. (JHAR00272). H. E. singularis (Faust, 1898) comb. nov. (JHAR00283). Scale bars = 1 mm.

Fig. 3. Head and prothorax in lateral view of species of Elaeidobius Kuschel, 1952 (Part 2). A. E. pilimargo Haran & Kuschel sp. nov. (JHAR00409). B. E. piliventris Haran & Kuschel sp. nov. (JHAR02182). C. E. plagiatus (Fåhraeus, 1844) comb. nov. (JHAR00272). D. E. singularis (Faust, 1898) comb. nov. (JHAR00283). Not to scale.

Fig. 4. Penis of males of species of the genus Elaeidobius Kuschel, 1952 in dorsal (left) and lateral (right) view. A. E. bilineatus (Hustache, 1924) comb. nov., Dakar, Senegal. B. E. spatulifer (Marshall, 1950) comb. nov., holotype, Thysville, Democratic Republic of Congo (MRAC). C. E. subvittatus (Faust, 1898), Dakar, Senegal. D. E. kamerunicus (Faust, 1898) comb. nov. (JHAR00209). E. E. pilimargo Haran & Kuschel sp. nov. (JHAR00409). F. E. piliventris Haran & Kuschel sp. nov. (JHAR02182). G. E. plagiatus (Fåhraeus, 1844) comb. nov. (JHAR00272). H. E. singularis (Faust, 1898) comb. nov. (JHAR00283). Scale bars = 100 µm.

Fig. 5. Details of morphology of Elaeidobius spp. A. Pronotum of E. subvittatus (Faust, 1898) in dorsal view showing the flat pronotum and the lateral cuticular expansion near head. B. Pronotum of E. subvittatus (Faust, 1898) in ventral view, showing the trilobate cuticular expansion between the coxae. C. Pronotum of E. plagiatus (Fåhraeus, 1844) comb. nov. in dorsal view showing the fovea on either side of midline. D. Apex of rostrum of E. bilineatus (Hustache, 1924) comb. nov. in lateral view. E. Apex of rostrum of E. subvittatus (Faust, 1898) in lateral view showing the protruding tubercle on underside. F. Elytra of E. bilineatus (Hustache, 1924) comb. nov. in dorsal view. G. Elytra of E. subvittatus (Faust, 1898) in dorsal view. H. Elytra of E. singularis (Faust, 1898) comb. nov. in lateral view. I. Elytra of E. kamerunicus (Faust, 1898) comb. nov. in lateral view. J–K. Abdominal sternites of male of E. piliventris Haran & Kuschel sp. nov. showing the median impression of the first two segments, flanked by a fringe of semi-erect hairs. L. Scutellum of E. plagiatus (Fåhraeus, 1844) comb. nov. in lateral view showing erect setae on tumescent base of interstria 4. M. Pronotum of dark specimens of E. subvittatus (Faust, 1898) in dorsal view. Not to scale.