Bicyclus rileyi Condamin

Brattström, Oskar, Aduse-Poku, Kwaku, Collins, Steve C. & Brakefield, Paul M., 2015, Revision of the Bicyclus ignobilis species-group (Lepidoptera: Nymphalidae: Satyrinae) with descriptions of two new species, Zootaxa 4018 (1), pp. 57-79 : 65

Bicyclus rileyi Condamin

( Figs. 7–10 , 29–30 )

Bicyclus rileyi Condamin 1961 (Bitje, Ja River, Cameroon)

Bicyclus rileyi Condamin 1965a (Separate description of female neallotype)

Material studied. Type material. Holotype ♂: Cameroon, Bitje, Ja River, (3°09’N, 13°00’E), G.L. Bates leg., BMNH (E) #997642 ( BMNH). Neallotype: ♀: Same locality as holotype, iv-vi.1910, G.L. Bates leg., BMNH (E) #997643 ( BMNH).

None-type material. Cameroon: Dja River (3°09’N, 13°00’E): 7 ♂. Ebogo (3°23’N, 11°28’E): 7 ♂, 8 ♀. Maan (2°22’N, 10°37’E): 4 ♂, 1 ♀. Membele (2°27’N, 11°08’E): 1 ♂. Mevele (Membele?): 3 ♂. Mintom (2°42’N, 13°17’E): 1♀. Moloundou (3°09’N, 13°00’E): 1 ♀. DRC: Lukolela (1°03’S, 17°12’E): 1 ♂.

Diagnosis. The size alone sets this species well apart from all other morphologically similar looking taxa. The forewing length of the male holotype is 27 mm and the female allotype 31.5 mm. The forewing measurements of males from the other species are usually in the region of 20 mm with females measuring just a few mm longer. The male androconial structures ( Fig. 10 ) are somewhat intermediate compared to more distinctly different members in the species-group. There is a rather thick cover of shiny dark scales and hairs in most of the anal areas of the dorsal hindwing and a comb of dark hairs covering the base of vein 1 on the dorsal forewing. The banding pattern on the ventral side is highly irregular, and the forewing shape is more drawn out towards the apex in the male compared to any of the other species in the group ( Fig. 7 ). The ventral eyespots follow a more even curve than in the other ignobilis -group members. The light pattern on the female dorsal surfaces is much enlarged, reaching well down under the eyespot in space 2 and continuing into space 1b and 1a ( Fig. 8 ). Just like the male, the female is very large compared to any of the other species in the group.

Distribution. Southern Cameroon and western DRC ( Fig. 29 ). This species was previously only known from the type pair collected in Bitje, Cameroon in 1910, and described some 50 years later by Condamin (1961; 1965). Since the beginning of the current century, collectors working for ABRI in Cameroon have found a further 34 specimens from a range of locations south of Sanaga River. In 2013 a single specimen was collected in Lukolela in DRC, suggesting an even larger range than previously reported ( Brattström 2012). It has been suggested as likely to be present in Gabon, but despite extensive collection efforts in the country no specimens have yet been found (Vande weghe 2010). Given the small amount of collected material known in total for such a large conspicuous species, and mostly from areas where large collection efforts have recently been made, it is likely that the species is highly localised or has a behaviour making it likely to escape detection.

Figures

FIGURES 7 – 10. Bicyclus rileyi Condamin 1961. 7. Male, Cameroon (OB – ABRI – 1021). 8. Female, Cameroon (KAP – ABRI – 12 – 578). 9. Male genitalia, Cameroon (OB – ABRI – 0050). 10. Androconial structures (ABRI – 14 – 657): There is a dark comb of hairs (but no brush like hair-pencil) in the basal area of space 1 b on the dorsal forewing (encircled in white). The anal area of the hindwing has a dense cover of dark shiny hairs and scales. The hindwing cell-brush is mainly covered by the forewing so that only the most basal parts are visible.

FIGURES 27 – 29. Distribution maps for the Bicyclus ignobilis species-group. Records of different species from the same site have been slightly offset when presented in the same map so that all species symbols can be clearly seen. Multiple records close to each other have been collapsed to a single point. The complete distributional data is available in Supplementary Table 1. 27 – 28. B. ignobilis (Open Squares) and B. maesseni (Open Crosses). 27. West Africa up to the Cameroonian border. 28. Cameroonian border and eastwards. 29. Remaining species occurring between Nigeria and Eastern DRC: B. brakefieldi (Filled Circles). B. ottossoni (Filled Crosses). B. rileyi (Open Circles). B. vandeweghei (Filled Diamonds).

FIGURES 30 – 36. Identification of females from the ignobilis- group. The images are not shown to scale, arrows indicate the main characters of importance for identification. 30. B. rileyi is much larger than any other species and the light markings in the apical patch continue below the eyespot in space 2, and often reach the lower margin of the wing. 31. B. maesseni has the edge of the apical patch more broken up in the area closest to the apical eyespot. Also, vein 4 is heavily marked with darker scales, breaking up the patch along its entire length. 32. B. ignobilis (western part of range) almost always lack the ventral hindwing spot in space 3, the apical patch is also much more solid than in B. maesseni with vein 4 just making a dark indentation in the basal part of the light patch. 33. B. ignobilis (eastern part of range) has vein 4 more heavily darkened so that the apical patch is sometimes fully broken up in sections. This makes them appear similar to B. maesseni, but the latter species is not sympatric in the eastern part of the range of B. ignobilis. The ventral discal band gradually gets a more pronounced edge at the end of the cell on both wings in a clinal fashion towards the east of the species range. 34. In B. ottossoni the basal part of the apical patch lacks indentations of dark scales along vein 4. The outer borders of the patch are much better defined than in the other species. The distal margin of the forewing is also much less convex, giving the wing a more squared shape. 35. B. vandeweghei have much more prominent light shading around the hindwing eyespots. The apical patch is otherwise similar to B. ignobilis. 36. B. brakefieldi have a more yellowish colour in the apical patch, and the part of the patch being placed basally of the eyespot is a bit fainter than in other species.