Ctonoxylon hirsutum Hagedorn, 2024

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 hirsutum Hagedorn stat. rev.

Figs 23 , 26 , 29

Ctonoxylon camerunum hirsutum Hagedorn, 1910: 4.

Ctonoxylon flavescens hirsutum Hagedorn , transfer by Eggers 1920 and Schedl 1961.

Type material.

Syntype (metatype sensu Eggers): Kamerun, Conradt leg. [ NHMW] .

Diagnosis.

Body length 2.5–3.0 mm, 2.2–2.3 × as long as broad; colour pale brown. Male frons slightly flattened on lower half, very slightly shrivelled, surface finely rugose above, female frons smooth, vestiture in the frons of both sexes consisting of fine setae. Eye parts separated by the size of upper eye; antennal club sutures not clearly marked; anterior lateral margin of prothorax at middle with acute eye scraper; a sharp carina running from eye scraper to near procoxa; propleural pit absent; elytral vestiture on each interstriae consisting of two irregular rows of slightly curved bristle-like setae and scattered very fine hair-like setae; elytral suture straight; elytral apex slightly emarginated, a few small and sharp tubercles along the posterior margin. Metanepisternum with mixed short plumose and hair-like setae; metaventrite with simple hair-like setae; these sclerites on its anterior third glabrous, with a vertically curved swollen trace of mesotibia’s resting position.

Distribution.

Ghana, Cameroon, Democratic Republic of the Congo, Gabon.

New records.

Cameroon, Ekande, 5 km N Limbe [GIS: 4.081, 9.172], 1100 m alt., ex unknown liana, 18. XI. 2007, A. Breistøl, leg. [1, ZMUB] ; Cameroon, Mbalmayo Forest Reserve, Eboufek [GIS: 3.499, 11.883], 28. 07. 1993, FIT [1, NHMUK] ; Republic of the Congo, 40–60 km ESE of Bomassa [2.04, 16.59], 18. 04. 1993, D. H. Chadwick leg. [1, USNM] .

Biology.

All records are from lowland rainforest sites in the western parts of Africa. It was previously collected from latex rich lianas ( Schedl 1961). In the current study two further specimens were dissected from a dead liana together with specimens of C. pilosum sp. nov. One specimen was also collected in a flight intercept trap [ NHMUK].

Comments.

Very similar to C. flavescens , except the elytral interstriae have fine pubescent ground vestiture and the two teeth near the anterior margin of the pronotum are subcontiguous. Previously designated as a variety of C. flavescens , but with a type designated, a subspecies name given and published by Hagedorn (1910). Sufficient diagnostic features as detailed by Eggers (1920), and molecular data demonstrating deep divergence from C. flavescens (Table 4 ), strongly support species status for the name hirsutum . Records from Ghana and Gabon (see Schedl 1961) could not be verified but these seem likely given several validated records from nearby countries.

Figures

Figures 21–29. Dorsal, lateral, and front views of male 21, 24, 27 Ctonoxylon flavescens 22, 25, 28 Ctonoxylon bosqueiae holotype, and 23, 26, 29 Ctonoxylon hirsutum stat. rev.