Elaeidobius kamerunicus ( Faust, 1898 ) Haran & Beaudoin-Ollivier & Benoit & 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 : 11-14

Elaeidobius kamerunicus ( Faust, 1898) comb. nov.

Figs 1D , 2D , 4D , 5I

Derelomus kamerunicus Faust, 1898: 225 .

Derelomus callosus Hustache, 1924: 76 [syn. by Marshall 1930: 575].

Derelomus congoanus Hustache, 1924: 77 [syn. by Marshall 1930: 575].

Material examined

Holotype

CAMEROON • ♀; “Kamerun. Kraatz” “ kamerunicus Fst. ” “ type ” “Coll. J. Faust. Aukauf 1900” “Staatl. Museum für. Tierkunde Dresden” “ Holotype ♀. Derelomus kamerunicus Faust, 1898 . Kuschel 2013” “ Elaeidobius kamerunicus ( Faust, 1898) . Kuschel 2013”; MTD.

Other material

CAMEROON • 2 ♂♂, 2 ♀♀; Edu Ngat; 2008; JHAR00209_0101; CBGP .

DEMOCRATIC REPUBLIC OF CONGO • 1 ♂, lectotype of Derelomus callosus Hustache, 1924 [here designated], labelled as “ Elaeidobius kamerunicus ( Faust 1898) . Kuschel 2009”; Yambata; 10 Dec. 1912; R. Mayné leg.; MRAC • 2 ♂♂, paralectotypes of Derelomus callosus Hustache, 1924 , labelled as “ Elaeidobius kamerunicus ( Faust 1898) . Kuschel 2009”; Kindu; Nov. 1913; L. Burgeon leg.; MRAC • 1 ♀, lectotype of Derelomus congoanus Hustache, 1924 [here designated], labelled as “ Elaeidobius kamerunicus ( Faust 1898) . Kuschel 2009”; Haut-Uelé, Moto; 1920; L. Burgeon leg.; MRAC • 8 ♀♀, paralectotypes of Derelomus congoanus Hustache, 1924 [here designated], labelled as “ Elaeidobius kamerunicus ( Faust 1898) . Kuschel 2009”; Yambata; 10 Dec. 1912; R. Mayné leg.; MRAC • 1 ♀; Mobwasa ; 30 Nov. 1912; R. Mayné leg.; MRAC • 1 ♂, 1 ♀; Haut-Uelé, Moto ; 1922; L. Burgeon leg.; MRAC • 1 ♀; Kindu; Nov. 1913; L. Burgeon leg.; MRAC. Other specimens identified and labelled by G. Kuschel in MRAC, MNHN, NHMUK, NZAC, MTD, USNM and ZMB.

ANGOLA • 12 ♂♂, 18 ♀♀; CE Salazar; 9.16º S, 14.55º E; 14 May 1973; Carvalho leg.; oil palm inflorescence; TMP .

Diagnosis (♂ ♀)

BODY LENGTH. 2.5–3.5 mm.

COLOUR. Dull dark brown, elytra with large yellow or reddish brown spot on either side at apex and on all or part of base, in male with long erect setae on margins, erect setae and a setiferous tuft on suture.

HEAD. 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 1.1 × as short as prothorax, in female 1.5 × as long as prothorax, cylindrical, 5-carinate in basal half, underside in male with short erect hairs and no postmental tubercle.

PROTHORAX. Disc in lateral view nearly flat, usually with minute fovea on either side of middle; carina fine, in male obsolete or obsolescent on basal half, ending in prominent, somewhat auriculate carina without constriction at base of collar.

ELYTRA. In male alutaceous, dull, moderately curved from shoulders to apex; base of interstria 4 usually raised to a yellow tumour or swelling bare of erect hairs; apical ¾ of sutural interstria raised, bearing long erect setae; interstria 9 in male swollen, somewhat inflated, bearing long curved erect setae, in female costate, with costa flat, not continued to apex.

ABDOMEN. Tergites heavily pigmented; tergite 7 strongly advancing forward against 6 in middle, with well-pigmented stridulatory rods, each rod containing about 15 granules.

GENITALIA. Penis as long as last three ventrites; body about 3 × longer than wide (ratio w/l: 0.36), symmetrical, sides sub-parallel, relatively broadly rounded at apex ( Fig. 4D ); with small median sclerites in the body.

Life history

On and in flowers of Elaeis guineensis (Arecaceae) , the oil palm. Males and females show a peak of flight activity around the inflorescences between 3 and 6 hours after sunrise ( Auffray et al. 2017).

Distribution

Benin (Cotonou, Dassa, Niaouli, Pob è); Cameroon (Edu Ngat, Kienke, Moliwe, N´Kongsamba); Democratic Republic of Congo (Beni: Ituri Forest, Haut-Uelé: Moto, Kindu, Mobwasa, Yambata, Yambula); Gabon (Kome Estate); Ghana (Kwae); Ivory Coast (Bonoua, Lamé); Madagascar (Melville); Nigeria (Ibaden, Obaretin, Cowan); Togo (Kloto). Introduced to other countries to aid pollination of oil palms in plantations: Americas: Brazil (Moju); Colombia (Campo Allegre, Finca la Roca, Girardot, La Cabana, Palmar del Casanare); Ecuador (Shushufindi); Guatemala (Tecum Uman); Peru (Palmas de Shanusi). Asia: Burma (Thanintharyi); Indonesia (Aek Loba, Bangun Bandar, Kota Gelanggi, Lae Butar, Mata Pao, Negeri Lama, Seumanyam, Sungei Liput, Tanah Gambus, Bangka, Belitung, Kalimantan Center, East Kalimantan, Lampung, North Sumatra, Papua, Riau, West Kalimantan, South Kalimantan, South Sumatra); Malaysia (Tun Razak); Thailand (Banhariz, Sji Nigena Toem, Koandi, Konho, Krabi Noi).

Remarks

Elaeidobius kamerunicus is distinctive in its dark body colour and yellow spots on elytra. This species is being imported by increasing numbers of countries to facilitate pollination of oil palms in plantations ( Syed 1982). In its native range, E. kamerunicus exhibits two genetically differentiated populations that are roughly distributed on each side of the cameroon volcanic line ( Haran et al. 2020). This taxon was described based on a single female from Cameroon without more detailed indications. In the collection of J. Faust housed at MTD, we found this specimen with the identification “ kamerunicus ” and bearing a red “type” label. This specimen is the holotype of Derelomus kamerunicus Faust, 1898 and was labelled accordingly. Derelomus callosus Hustache, 1924 was described based on a series of individuals from two localities of the Democratic Republic of Congo (Yambata, 10 Dec. 1912 and Kindu, Nov. 1913). This species was later put in synonymy with D. kamerunicus (= Elaeidobius kamerunicus ) by Marshall (1930), but no particular specimen from these series was designated as holotype. In the collections of the MRAC, three male specimens from these localities and bearing the red labels “ Holotypus ” and “ Paratypus ” were located. The specimen from Yambata and bearing the label “ Holotypus ” is here designated as the lectotype for D. callosus . The two specimens from Kindu and bearing the label “ Paratypus ” are labelled as paralectotypes. Derelomus congoanus was described based on a series of individuals from two localities of the Democratic Republic of Congo (Yambata, 10 Dec. 1912 and Haut-Uelé, Moto, 1920). This species was also put in synonymy with D. kamerunicus (= Elaeidobius kamerunicus ) by Marshall (1930). The specimens used to describe Derelomus congoanus are in fact females of Elaeidobius kamerunicus that Hustache took to be a distinct species. As for the previous species, no particular specimen from the type series was designated as holotype. In the collection of the MRAC, one female from Haut-Uelé (1920) and bearing a red label “ Holotypus ” was located. It is here designated as the lectotype of Derelomus congoanus and labelled accordingly. In the same collection, 8 females from Yambata (10 Dec. 1912) and bearing a red “ Paratypus ” label were labelled as paralectotypes of this species.

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. 2. Head and prothorax in lateral view of species of Elaeidobius Kuschel, 1952 (Part 1). 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). 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.