Ctonoxylon montanum Eggers, 1922

Jordal, Bjarte H., 2024, An integrated taxonomic revision of Ctonoxylon (Coleoptera, Curculionidae, Scolytinae) reveals new Malagasy species originating from multiple recent colonisations of the island, ZooKeys 1203, pp. 95-130 : 95-130

Ctonoxylon montanum Eggers

Figs 31 , 34 , 37 [female]; 32, 35, 38 [male ]

Ctonoxylon montanum Eggers, 1922: 170.

Ctonoxylon longipilum Eggers, 1935: 308 , syn. nov.

Ctonoxylon nodosum Eggers, 1940: 236 , syn. nov.

Links.

https://www.barkbeetles.info/photos_target_species.php?lookUp=7979. https://www.barkbeetles.info/photos_target_species.php?lookUp=2193.

Type material.

Holotype female: Kamerun, Buea , XII. 10, Hintz, leg. Type 60341 [ USNM] . Holotype of Ctonoxylon longipilum , female: [ Tanzania] Mulange , Br. O. Afr. Type 60340 [ USNM] . Holotype of C. nodosum , male: [Democratic Republic of the Cogo] Congostaat , Mongbwalu [1.93, 30.05], [1200 m alt.] Mm Scholtz [ RMCA] .

Diagnosis.

Length 3.2–3.6 mm. 2.0–2.1 × as long as broad; colour brown. Upper and lower eye parts separated by 1.5 × the width of upper part; pronotal eye scraper acutely pointed; a sharp carina running from scraper to procoxa, without associated groove or propleural pit; scutellar shield at level with elytra; striae distinctly impressed, interstriae rounded, interstrial setae curved and bristle-like, variable in length and scattered irregularly within rows, denser on declivity, without ground vestiture; elytral apex in females slightly extended, entire, in males apical interstriae 1 and 2 fused and strongly inflated; resting position of mesotibiae marked on metaventrite.

Distribution.

Ivory Coast, Ghana, Nigeria, Cameroon, Democratic Republic of the Congo, Uganda, Kenya, Tanzania

New records.

Ghana, Ashanti region, Kwadaso, 320 m., N 6.42 ’ – W 1.39 ’, Dr. S. Endrödy-Younga, mixed light, 25. II. 1969 [1, NHMW] ; Ghana, Western Region, Ankasa , Nkwanta Camp , 8. 6. 2005, KB Miller, leg. [1, ZMUB] ; Nigeria, Ibadan [7.40, 3.85], 01. 11. 1964, M. L. Jerath leg. [2, USNM] ; Nigeria, Ife , W. State [7.48, 4.48], 01. 08. 1971, T. Medler [3, USNM] ; Cameroon, Libamba, 10 km E of Makak [3.54, 11.09], 11. 02. 1974, black light, J. A. Gruwell leg. [1, USNM] .

Comments.

Type specimens of C. longipilum and C. montanum are near identical and synonymised. The first species has only slightly longer curved elytral setae, but this feature varies between specimens. All specimens of the two nominal taxa are females as characterised by the pair of raised teeth along the anterior margin of the pronotum. Previously Schedl (1972) synonymised C. nodosum with C. longipilum due to the presumed sexual dimorphism expressed in the inflated elytral apex and the lack of raised teeth along the pronotal margin. Schedl’s view is supported and the synonym C. nodosum is therefore moved to C. montanum .

The record from Madagascar as C. longipilum (see Schedl 1977) is likely a misidentified female specimen of C. tuberculatum sp. nov. and is removed from the distribution list. Basically nothing is known about its biology except coming to light at lower to middle altitudes.

Figures

Figures 30–38. Dorsal, lateral, and front views of 30, 33, 36 Ctonoxylon tuberculatum sp. nov. male holotype 31, 34, 37 Ctonoxylon longipilum female (= C. montanum), and 32, 35, 38 Ctonoxylon nodosum male holotype (= C. montanum).