Chortastus minimus Hagedorn 1909

Chortastus minimus Hagedorn, 1909 (Figs 9–18) Chortastus minimus Hagedorn, 1909: 738. Chortastus medius Eggers, 1924: 100, syn. nov. Chortastus agnatus Eggers, 1935: 301, synonym by Browne, 1973. Chortastus sulcatus Eggers, 1935: 301, synonym by Browne, 1973 Chortastus brunneus Nunberg, 1967: 317, synonym of C. medius by Browne, 1973. Afrochramesus baguenai Schedl, 1971: 197, synonym of C. medius by Beaver, 1998. Type material. Syntypes: Cameroon [ZMHB]. Syntype of Chortastus medius: Congostaat [Democratic Republic of the Congo], Albertville [Kalemie] 1.XII.1918, R. Mayné, leg. [MRCA]. Lectotype of Chortastus agnatus: Cameroon, Conradt, leg. [USNM]. Holotype of Chortastus sulcatus: [Democratic Republic of the Congo], Sankuru, 1.IV.1925, ex Staudtia gabonensis, Lt. Ghesquière, leg. [MRCA]. Holoty,pe of Chortastus brunneus: [Democratic Republic of the Congo], Bas-Congo, Kimwenza, 1.IV.1956, R. P. Van Eyen, leg. [MRCA]. Other material. Congo-Brazzaville [Republic of Congo], Sibiti, leg. Endrödy-Younga, 27.11.1963 [NHMW]. Democratic Republic of the Congo, Mulongo, [Haut-Lomami], 20.5.1930, P. Gerard, leg. [NHMW]; Yangambi, 14.12.1951, K. E. Schedl, leg. [NHMW] and 17.VII.1952 [MRCA]. Diagnosis. Body length 1.6–2.7 mm, 2.1–2.2 × as long as wide. Male frons with long golden setae from vertex and near eye margin reaching near epistoma, female frons with very short erect setae evenly distributed over entire frons; pronotum and elytra with similar type of setae, on elytral interstriae in a single row or in variably confused multiple rows; interstriae 2 on declivity slightly impressed, smooth and glabrous, interstriae 3 on lower half of declivity with a slightly elevated blunt ridge. Distribution. Democratic Republic of the Congo, Republic of Congo, Cameroon, Angola. Host plant: Staudtia stipitata (Myristicaceae). Remarks. Comparison of (holo-) types of C. minimus, C. medius, C. sulcatus, C. brunneus and C. agnatus, and a paratype of C. baguenai revealed a gradual variation from smallest (minimus, agnatus and sulcatus) to medium (baguenai) to largest (medius), and from slightly more spaced setae (minimus and agnatus) to a little denser (sulcatus, brunneus and medius). Because all these species were described from nearby locations in the greater Congo basin, and that body size is known to vary a great deal in phloem feeding bark beetles, these intergrading types are inferred as conspecific. Published as part of Jordal, Bjarte H., 2025, Taxonomic revision of the rare Afrotropical genus Chortastus Schaufuss (Coleoptera: Scolytinae), pp. 77-84 in Zootaxa 5647 (1) on page 80, DOI: 10.11646/zootaxa.5647.1.5, zenodo.org