Achrocerides flavoantennata ( Berio, 1937 ) Taberer & Giusti, 2022

Taberer, Tabitha R. & Giusti, Alessandro, 2022, Revision of Achrocerides Hering, 1937 (Lepidoptera: Chrysopolomidae), Ecologica Montenegrina 59, pp. 24-37 : 33-34

Achrocerides flavoantennata ( Berio, 1937) comb. n. ( Figs. 6 — 8 , 16 — 17 )

Chrysopoloma flavoantennata Berio, 1937 , Annali del Museo civico di storia naturale Giacomo Doria, 59: 383. Type locality: DRC, between Coquilhatville [Mbandaka] and Stanleyville [Kisangani].

Type material examined. Holotype (photograph examined): Male, “HOLOTYPUS ♂ / Chrysopoloma flavoantennata / E. Berio, 1937 ” // “Museo Civico / di Genova ” // handwritten “ Chrysopoloma / flavoantennata / Berio ” / “DET. BERIO” // “TYPUS” // “ Nel tratto del Congo / da Coquilhatville / a Stanleyville / ott: 1930” // Gen. slide No.: MCSN- Genova, Zolotuhin pr. GU 2010-02 (image examined) ( MCG).

Additional material examined: DRC. 1 male, Upper Lowa Valley , near Masisi, W. Kivu, 5000 — 6000 ft, forest & long grass, ii.1924, Barns, T.A., unique QR code: NHMUK 014201444 , gen. slide No. : NHMUK 010317725 ( NHMUK) ; 1 male, Kabunga , Masisi Territory, Nord-Kivu, 600 — 700 m, 13.ix.1945, gen. slide No.: TT 132 ( ANHRT) ; 1 male, Maniema , Territory Kindu, viii.1959, Hecq, J. leg., gen. slide No.: CHRY-11-80 (Kurshakov pr.) ; 1 male, Equateur , Moutombe [=Mondombe], 25.ii.1930, Oostermans, F. leg., gen. slide No.: TT 198 ; 2 males, Equateur , Flandria, 11.ii.1930 — viii.1931, Hulstaert, G. leg., gen. slide Nos.: TT 199, TT 200 ( RMCA) .

The male genitalia are described here for the first time.

Description

Male. Forewing length: 26.5 — 27.5 mm. Head, collar, tegula, and thorax tawny brown. Antenna bipectinate; antennae and palps ochreous yellow. Legs beige laterally with sparse dark scale spots, ochreous yellow medially. Abdomen uniformly brown-beige, sometimes with a few, irregular black scale spots. Forewing. Broad, rounded; ground colour greyish-beige to tawny-brown, speckled sparsely with dark scales that are mostly concentrated along costal margin and near thorax; wing colour slightly paler from post-medial line to distal edge. Post-medial line grey-brown, with scaling extending on the veins distally; post-medial line kinked at vein m1 near outer margin; wing colour slightly paler from post medial line to distal edge. Postmedial area with a diffuse grey-brown triangular patch between veins R3 and M1; discal spot light beige, rounded, with diffuse margin. Fringe long, slightly darker than ground colour, cilia sometimes black in distal half. Hindwing. Rounded, with undulate margin at the tornus. Ground-colour same as forewing or slightly paler; medial line dark grey-brown, wider than that of forewing. Sparse dark scales concentrated in the distal half. Outer margin with a diffuse, pale grey-brown triangular patch between veins M1 and M2. Fringe long, slightly darker than ground colour, cilia black in distal half. Underside of wing uniformly pale beige with some irregular grey scales concentrated mostly along the costal margin of the fore- and hindwing. Underside of wing uniformly pale beige with some irregular clusters of grey scales concentrated mostly along the costal margin of fore- and hindwing. Forewing discal spot traceable. Outer margin with diffuse pale grey-brown triangular patch between veins R3 and M1 on forewing and between veins M1 and M2 on hindwing. Fringe darker than ground colour; cilia sometimes black in distal half.

Female. Unknown.

Male genitalia. Uncus elongate, triangular, flat and strongly sclerotised apically. Tegumen narrow. Transtilla comprised of two long slender, apically pointed posterior processes, and two slightly narrower, short, triangular, apically rounded anterior processes strongly connected medially via a membrane. Juxta with large, bilobate base, with small, strongly sclerotised, rectangular process antero-medially, and with two moderately long, narrow, triangular, distally pointed lobes accompanying phallus laterally. Vinculum broad, rounded. Valve wide at base, triangular, with rounded point distally on dorso-apical edge. Phallus medially curved, relatively thin, long, proximally surrounded with heavily sclerotised manica fused ventrally to caudal lobes of juxta, weakly sclerotised distally with apical split. Vesica extremely short, membranous.

Taxonomic note. In the original description of C. flavoantennata, Berio (1937) suggests that his species may be the male of Strigivenifera albidiscalis (Hampson, 1910) which was described based on a female holotype from DRC. However, on examination of external morphology of the C. flavoantennata holotype, it was confirmed that this species is congeneric with A. theorini due to the typical dark speckles across both fore- and hindwings as well as the lack of defined brown wing venation characteristic of Strigivenifera . Furthermore, the general male genital structure of the C. flavoantennata holotype showed marked similarities to that of A. theorini , such as the two elongate posterior processes of the transtilla and the long, thin, distally weakly sclerotised phallus (albeit with diagnostic differences which are discussed below), whilst lacking the typical generic features found in Strigivenifera taxa. This species is thus transferred to Achrocerides : Achrocerides flavoantennata ( Berio, 1937) comb. n.

Diagnosis. This species is considerably larger in size than both A. theorini and A. smithi sp. n. and specimens are generally slightly darker and more greyish in colour. When comparing the male genitalia with A. theorini , the clasping apparatus is overall larger in size, the two anterior transtilla processes are shorter and slightly broader, and fused medially with a more heavily sclerotised membrane. In addition, the juxta processes of A. flavoantennata are noticeably wider and shorter, and the valva is much more triangular and less truncate, with a much longer and more pointed dorso-apical edge compared to the related species.

Distribution ( Fig. 20 ). Found only in DRC, this species exists in sympatry with A. theorini although it appears to be much rarer. It is distributed within the rainforests of the Congo Basin extending its range to the mountainous Nord-Kivu region in the east. The holotype was collected by Lidio Cipriani, an anthropologist and zoologist who visited DRC in 1930. It has rather vague locality data, given as “In the stretch of the Congo between Coquilhatville [Mbandaka] and Stanleyville [Kisangani]”, but since Cipriani travelled via boat along the Congo River during his expedition ( Cipriani 1932), the type locality of A. flavoantennata in Fig. 20 is given as approximately halfway along the river between the two cities.

Figures

Figure 20. Distribution of Achrocerides species (TL = Type locality).

Figures 1—10. Adults. Figs. 1—5: Achrocerides theorini. 1: ST, Male, Gaboon [Gabon] (SMNH); 2. Male, Angola, Quicolungo (gen. slide No. NHMUK 010317727) (NHMUK); 3. Male, Sierra Leone, Kono Province (ANHRT); 4. Male, Uganda, Kibale Forest (gen. slide No. 31.061) (MWW); 5. Female, Liberia, Nimba Mountains (gen. slide No. LG 5794) (ANHRT). Figs. 6—8: Achrocerides flavoantennata comb. n., 6: HT, male, DRC, (GU 2010-02) (MCG); 7. Male, DRC, Kabunga (gen. slide No. TT 132) (ANHRT); 8. Male, DRC, Maniema (gen. slide No. CHRY-11-80) (RMCA). Figs. 9—10: Achrocerides smithi sp. n., 9: HT, male, Central African Republic, La Maboke (gen. slide No. CHRY-11- 84) (RMCA); 10: Male, Central African Republic, La Maboke (gen. slide No. TT 201) (RMCA).

Figures 16-19. Genitalia (a: clasping apparatus, b: phallus). Figs. 16—17: Achrocerides flavoantennata comb. n., 16: Male, DRC, Kabunga (gen. slide No. TT 132) (ANHRT); 17: Male, DRC, Moutombe [=Mondombe] (gen. slide No. TT 198) (RMCA). Figs. 18—19: Achrocerides smithi sp. n., 18. HT, Male, Central African Republic, La Maboke (gen. slide No. CHRY-11-84) (RMCA); 19: Male, Central African Republic, La Maboke (gen. slide No. TT 201) (RMCA).