Strigivenifera albidiscalis Kurshakov & Zolotuhin, 2013

Taberer, Tabitha R., 2022, An updated review of the genus Strigivenifera Hering, 1937 (Lepidoptera Zygaenoidea: Chrysopolomidae) with the description of a new species, Zootaxa 5168 (1), pp. 51-62 : 53

Strigivenifera albidiscalis Kurshakov & Zolotuhin, 2013

Prior to its revision by Kurshakov & Zolotuhin (2013), Strigivenifera was considered to be monotypic ever since Hering (1937) synonymised S. albidiscalis (TL: DRC) with the type species S. venata (TL: Gabon), associating the respective female and male holotypes due to their similar external habitus. Matching males to a female holotype can be problematic in groups where external diagnostic characters are limited, and without the use of DNA barcoding it can sometimes be near-impossible to associate the two sexes. Kurshakov & Zolotuhin (2013) however, identified two males (one from DRC and one from Rwanda) as being conspecific with the female of S. albidiscalis based on the pattern and colouration of the wings and thus revived the species from synonymy; their conclusion is well supported by the barcodes of newly-sequenced males and a female found in the same regions (BOLD process ids.: ANLMN8461-21–ANLMN8463-21), as well as clear differences in the male genitalia of this species and S. venata .

Despite identifying and describing the male of S. albidiscalis for the first time, the authors also described two further species from roughly the same region of Central Africa: S. cruisa Kurshakov & Zolotuhin, 2013 (TL: Kenya) and S. livingstonei Kurshakov & Zolotuhin, 2013 (TL: DRC). A first issue with the description of these taxa is that no comparison with Hampson’s species is made despite their sympatric distribution and possession of an arcuate postmedial band of the hindwing. This lack of detailed diagnoses is problematic for identification purposes, with the only mention of difference in the external morphology being that S. cruisa is “smaller and distinctly paler” than S. livingstonei, a claim that cannot be considered a reliable distinguishing feature of two otherwise identical species.

Even more surprisingly, any perceived differences in the male genitalia are not discussed despite a number of specimens of all three taxa having been dissected as listed in the materials section. When comparing the male genitalia of the holotypes of S. cruisa and S. livingstonei and the male of S. albidiscalis , the clasping apparatus of all three have an identical groundplan characteristically consisting of a valve which is wide at the base and sharply narrowing medially, and a juxta with two lobes which gradually taper. In addition, the distal end of the aedeagus bears a paired cluster of strongly sclerotised cornuti in all three species (it must be noted that use of the term “cornuti” in Kurshakov & Zolotuhin (2013) is in reference to spine-like structures on the distal end of the aedeagus and not within the vesica; the present paper follows this terminology). In particular, the holotype dissection of S. cruisa is identical to that of the illustrated S. albidiscalis , and S. livingstonei may only be perceived as different in the thickness of the juxta processes. However, the absence of illustrations of additional specimens in the review makes it difficult to account for any intraspecific variability, and thus it is unclear whether this feature justifies its distinctiveness. The only notable differences considered by the authors between S. cruisa and S. livingstonei are that the valve is “digitate apically, and the aedeagus is large and bears a few cornuti” in S. cruisa, although this statement is true of both species as observed in their figures. Again, the lack of detailed comparative diagnoses makes it extremely difficult to maintain both taxa as valid.

In order to confirm the suspected synonymy of these three species, barcode-confirmed specimens were dissected and it was found that three male specimens from north-west Zambia ( BOLD process ids./gen. slide Nos.: ANLMN8454-21/ TT 111 ; ANLMN8460-21/ TT 112 ; ANLMN8457-21/ TT 113 ) and one specimen from Nord-Kivu, DRC ( BOLD process id./gen. slide No.: ANLMN8462-21/ TT 118 ) were identical in genitalia to each other and to those of S. albidiscalis , S. cruisa, and S. livingstonei ( Figs. 1–3 , 14–16 ). This result was considered surprising at first as there is a great deal of variation in the wing colouration of all these Central African specimens, implying that the darkness of the wings is not a reliable characteristic for distinguishing species in this genus, contrary to Kurshakov & Zolotuhin’s (2013) opinion; it also makes their comment on being able to identify species without needing dissection rather doubtful .

Further support that these three species are conspecific can be found in the results of the phylogenetic analyses. All of the specimens identified as S. livingstonei and S. cruisa by Kurshakov & Zolotuhin (2013) (BOLD process ids.: LBEOW2045-11; LBEOW2046-11; LIMBC811-11–LIMBC813-11; LIMBC817-11; LIMBC819-11; LIMBC820-11; LIMBC853-11) recovered closely within a clade alongside other Central African specimens (BOLD process ids.: ANLMN8452-21–ANLMN8463-21). The APWD between all specimens in this clade was 1.9%, and, given the sympatric distribution with no external distinguishing characters, this difference cannot be considered large enough for several distinct taxa. The phylogenetic reconstructions may support the idea that this species could be undergoing speciation, as several smaller, geographically grouped clusters were recovered; however, due to a clear lack of constant differences in external habitus and male genitalia, it is believed that these taxa represent a single, widespread species with a great degree of intraspecific variability. Given the morphological and genetic evidence as presented, both S. livingstonei and S. cruisa are here synonymised with S. albidiscalis : S. livingstonei Kurshakov & Zolotuhin, 2013 syn. n., S. cruisa Kurshakov & Zolotuhin, 2013 syn. n.

Figures

FIGURES 1–13. Adult male Strigivenifera (deposited at ANHRT unless otherwise stated). 1. S. albidiscalis, DRC (BOLD process id./gen. slide No.: ANLMN8462-21/TT 118); 2. S. albidiscalis, Zambia (BOLD process id./gen. slide No.: ANLMN8454- 21/TT 111); 3. S. albidiscalis, Zambia (BOLD process id./gen. slide No.: ANLMN8460-21/TT 112); 4. S. eborea, Ivory Coast (BOLD process id./gen. slide No. ANLMN8471-21/TT 114); 5. S. eborea, Sierra Leone (BOLD process id./gen. slide No.: ANLMN8472/TT 115); 6. S. eborea, Ivory Coast (BOLD process id./gen. slide No.: ANLMN8466-21/TT 123); 7. S. eborea, Ivory Coast (BOLD process id./gen. slide No.: ANLMN8465-21/TT 141); 8. S. smithi sp. n., HT, Sierra Leone (BOLD process id./gen. slide No.: ANLMN8475-21/TT 122); 9. S. smithi sp. n., PT, Sierra Leone (BOLD process id./gen. slide No.: AN- LMN8474/TT 121), 10. S. smithi sp. n., PT, Sierra Leone (gen. slide No.: TT 139); 11. S. bartschi (PT of S. tatooifera), DRC (gen. slide No.: CHRY-11-52) (RMCA); 12. S. bartschi, DRC (BOLD process id./gen. slide No.: ANLMN7892-21/TT 124); 13. S. bartschi, DRC (BOLD process id./gen. slide No.: ANLMN7890-21/TT 125).

FIGURES 14–20. Male genitalia of Strigivenifera (a. clasping apparatus; b. aedeagus). 14. S. albidiscalis, DRC (BOLD process id./gen. slide No.: ANLMN8462-21/TT 118); 15. S. albidiscalis, Zambia (BOLD process id./gen. slide No.: ANLMN8454-21/ TT 111); 16. S. albidiscalis, Zambia (BOLD process id./gen. slide No.: ANLMN8460-21/TT 112); 17. S. eborea, Ivory Coast (BOLD process id./gen. slide No. ANLMN8471-21/TT 114); 18. S. eborea, Sierra Leone (BOLD process id./gen. slide No.: ANLMN8472/TT 115); 19. S. eborea, Ivory Coast (BOLD process id./gen. slide No.: ANLMN8466-21/TT 123); 20. S. eborea, Ivory Coast (BOLD process id./gen. slide No.: ANLMN8465-21/TT 141).