Taxonomic revision of the genus Delorhachis Karsch 1896 (Lepidoptera: Limacodidae)

ABSTRACT This paper presents the first comprehensive revision of the Afrotropical genus Delorhachis Karsch, 1896. Through the utilisation of integrative taxonomic methods (external morphology, dissections of genitalia and DNA barcoding), we distinguish five species groups within the genus and herein describe 11 new species and one new subspecies: D. meyi sp. nov., D. nimbaensis sp. nov., D. pallidifascia sp. nov., D. parvinota sp. nov., D. smithi sp. nov., D. wetzelae sp. nov., D. wetzelae shambaa ssp. nov., D. manuelae sp. nov., D. tommasoi sp. nov., D. bakossi sp. nov., D. baaka sp. nov., and D. zambica sp. nov. We also remove D. charopa Bethune-Baker, 1909 stat. rev. from synonymy with D. viridiplaga Karsch, 1896. Several new taxonomic combinations are proposed: Chrysamma syntomoctena Tams, 1929 is transferred to Delorhachis (D. syntomoctena (Tams, 1929) comb. nov.) and Delorhachis amator Hering, 1928, D. amica Hering, 1928 and D. purpurea Hering, 1928 are transferred to Miresa (M. amator (Hering, 1928) comb. nov., M. amica (Hering, 1928) comb. nov., and M. purpurea (Hering, 1928) comb. nov.). Delorhachis schultzei Aurivillius, 1905 is synonymised with Hilipoda gravidipes Karsch, 1896 syn. nov. Miresa strigivena Hampson, 1910 is synonymised with D. nigrivenosa Karsch, 1896 syn. nov. Delorhachis denisae Dufrane, 1945 and Chrysamma erythrochrysa Tams, 1929 are synonymised with M. purpurea syn. nov. The females of D. viridiplaga and D. charopa and the male of D. chlorodaedala Tams, 1929 are described and illustrated for the first time. DNA barcodes were obtained for 55 specimens representing 14 taxa, and analyses were performed using maximum likelihood and Bayesian inference approaches; a tree resulting from the latter is provided. Pairwise distances of barcodes between taxa are provided where available. The adults and genitalia of all taxa, their habitats and distribution are illustrated in 182 colour figures and five distribution maps. http://www.zoobank.org/urn:lsid:zoobank.org:pub:0DED3725-84D8-4F0B-9219-F0EB25671194

The external appearance of Delorhachis is characterised by a reddish or ochreous ground colour decorated with a green, white or cream medio-ventral fore wing fascia, and black veins in the postmedial area of the fore wing. The vast majority of species also possess coloured patches on the thorax, providing a character that can be used for differentiating between species groups as described herein. The species show clear sexual dimorphism, with females being larger and having a longer medio-ventral fascia on the fore wing. The main generic characters in the male genitalia are the conspicuously elongate and distally highly modified valva, and the presence of long, slender, spur-like pseudocornuti on the manica (see Figure A). The female genitalia of this genus are characterised by a well-developed, heavily sclerotised post-vaginal plate and ductus bursae, and the often swollen distal section of corpus bursae, the small globular proximal section of corpus bursae, and the signum bursae consisting of two small, finely scobinate rounded plates ( Figure B).
Through studying specimens held in various Lepidoptera collections, remarkable heterogeneity in the shape, size and colour of the fore wing medial fascia was observed, suggesting the presence of several undescribed taxa. Despite the attractive habitus and suspected hidden diversity of the genus, Delorhachis has never been taxonomically revised. Solovyev's (2014) monograph on Asian Parasa Moore, [1860] provides a detailed description of the characters of the genus Delorhachis, based on a specimen in the MWW from Ivory Coast, at the time incorrectly identified as D. viridiplaga, the type species of the genus. However, this was found in the present paper to be a new species, described herein.
To understand whether all these differences in habitus were simply due to morphological variability, or indeed represented distinct species, we carried out numerous dissections of genitalia and genetic analyses based on DNA barcodes. These investigations have not only confirmed the existence of several hitherto unknown taxa, but also revealed the necessity for new generic combinations and introductions of new synonymies.
In the present paper, we provide an updated nomenclature of the genus Delorhachis and describe 11 new species and one new subspecies, and introduce four new generic combinations and four synonyms through analyses of external and genital morphology, as well as genetic data.

Morphological studies
Images of adults were taken using either a Canon EOS 650d/80d/850d DSLR camera equipped with a Sigma DG Macro 105 mm 1:2.8 or Canon Makro 60 mm lens or a Nikon D90 camera equipped with a Nikkor AF Micro 60 mm lens. The genitalia were dissected and stained with Eosin Y or Chlorazol Black, applying standard methods of preparation (Lafontaine and Mikkola 1987), then embedded in Euparal on microscope slides. The genitalia preparations were photographed using a Panasonic DMC-G70 camera attached to a trinocular Bresser Science infinity microscope or a Canon EOS 700D camera mounted on a Leitz Diaplan compound microscope.
Terminology of genitalia and wing morphology follows Solovyev (2014) with minor modifications (we use the term phallus instead of aedeagus).

Genetic studies
DNA barcodes were obtained by removing tarsal segments from 55 adult specimens (48 Delorhachis, five Miresa, one Hilipoda, and one Stroter Karsch, 1899) and submitting them to the Canadian Centre for DNA Barcoding (CCDB, Biodiversity Institute of Ontario, University of Guelph) for extraction, amplification and sequencing of cytochrome oxidase subunit I (COI-5P) applying single molecule real-time sequencing through the Sequel (PacBio) pipeline (Hebert et al. 2018). The samples included 10 putative Delorhachis taxa that yielded successful sequences. Stroter capillatus Karsch, 1899 was selected as an appropriate outgroup taxon as it is an Afrotropical member of the Parasa s.l. generic complex, a sister clade of Delorhachis (Solovyev 2014). All sequences and metadata are accessible in the BOLD public data set (data set: dx.doi.org/10.5883/DS-DELORH).
Sequences were aligned using MUSCLE in MEGA version X (Kumar et al. 2018) and pairwise distances within and between species were calculated using the Kimura twoparameter model (Kimura 1980). Phylogenetic tree searches were performed using Bayesian inference (BI) and maximum likelihood (ML). BI analyses were performed using MrBayes version 3.2.7a (Ronquist et al. 2012). Metropolis-coupled Markov chain Monte Carlo (MCMC) analyses were run with four chains (one cold and three heated) for 10,000,000 generations sampling every 100 generations, discarding the first 25% as burn-in. The two runs converged with the standard deviation of split frequencies 0.003. ML analyses were performed on CIPRES using the RAxML BlackBox utility (Stamatakis et al. 2008) with default settings and a GTR+FO+G4m model. Support for clades was evaluated for BI using posterior probabilities and ML using non-parametric bootstrapping. Trees were visualised and annotated in FigTree version 1.4.4 and Adobe Photoshop version 13.0.

Type label data
Information provided in quotation marks is transcribed verbatim. A new line is denoted with '|' and a different label with '||', and any additional information is provided in square brackets.

Characterisation of the species groups
Despite the rather uniform habitus of the majority of the Delorhachis species, the genus is divided into five lineages based on external morphology, genital characters and genetic data. The distinctive characters of the species groups are summarised in Table 1.

Phylogenetic analyses
The phylogenetic inferences based on BI and ML recovered very similar topologies with only the placement of D. ochsei sp. nov. being different between the two analyses. In the ML tree, D. ochsei was recovered as sister to a clade containing D. meyi sp. nov. + D. parvinota sp. nov. + D. pallidifascia sp. nov. The resolution of the BI tree was, however, increased and congruent with the morphological hypotheses as described in this review, and hence this tree is illustrated in Figure C. Delorhachis was recovered as paraphyletic with regard to Miresa, and D. schultzei was recovered as sister to Delorhachis + Miresa. Within clade A, there were two distinct lineages: clade B consisting of D. purpurea + Miresa, and clade C containing Delorhachis s.s. In both the BI and ML analyses, D. purpurea did not group with Delorhachis but was recovered as sister to M. gliricidiae Hering, 1933 with high posterior probability and bootstrap support values (1.0 and 88%, respectively). This was also reflected in morphological observations, with D. purpurea's simplified male genitalia and lack of pseudocornuti, and hence the following new combination is introduced: M. purpurea comb. nov. Delorhachis schultzei was recovered as sister to clade B in both analyses, receiving high posterior probabilities and bootstrap support values of 1.0 and 100%, respectively. The male genitalia of this species again lacked the generic features of Delorhachis, and in addition, the single male of D. schultzei sampled was recovered with a female of H. gravidipes, which has here resulted in the new combination and synonymy of H. schultzei comb. nov. with H. gravidipes (= H. schultzei syn. nov.).
Within clade C, D. nigrivenosa was recovered as sister to all other Delorhachis species, which is unsurprising given its distinctive morphological characters expressed by the pale colouration and simplified genitalia, whilst retaining the genus' main diagnostic characters. The distinctive D. smithi sp. nov. and D. syntomoctena comb. nov. were also recovered as a group separate from other Delorhachis, with both species displaying a white fore wing fascia and white tegula patch, as well as substantial differences in the genitalia. In addition, members of these two species groups have a tibial spur formula of 0-0-0. All species with the typical reddish fore wing ground colour and green fore wing fascia were recovered as a polytomy with strong posterior probabilities and moderate bootstrap support (0.78 and 36%, respectively), forming four distinct clades with D. meyi + D. parvinota + D. pallidifascia recovered in one group, D. viridiplaga + D. charopa stat. rev. in another, and both D. ochsei and D. chlorodaedala forming distinct units with relatively high intraspecific divergence. Interestingly, species possessing these reddish and green fore wing colours have a tibial spur formula of 0-2-2, suggesting that in this group, the trait is apomorphic. Further investigation of the presence or absence of tibial spurs in other Limacodidae is needed. Based on the external and genital morphology of these species, it would have been expected that D. chlorodaedala be recovered much closer to D. meyi + D. parvinota + D. pallidifascia as all of these species display a rounded, green fore wing fascia, a green tegula patch and central thorax patch; moreover, within the male genitalia, they share distally bilobed valva and a bunch comprising several pseudocornuti on the manica. It is also surprising that D. viridiplaga + D. charopa were not recovered in a group with D. ochsei as these three species are indistinguishable externally, but have clear differences in their genitalia and distribution. However, it is important to note that taxon sampling was incomplete for a number of species and this may have impacted the analyses; DNA barcoding specimens of the remaining Delorhachis species would likely result in a better resolved tree. Furthermore, it should be noted that the COI-5P gene fragment is short and so the addition of further gene regions would likely improve the resolution of the phylogeny. Overall, the topology of the Delorhachis clade is strongly supportive of the morphological species groups concept of this genus as presented here.

Taxonomic note
This species was described from male syntypes. The female adult and both female and male genitalia of the species are described here for the first time.

Description
External morphology. Female. Fore wing length 15-15.5 mm. Body and wing colour as in male but slightly paler. Antenna filiform. Fore wing. Broad, with outer margin more evenly arcuate than in males. Green medio-ventral fascia is markedly longer than in males, almost parallel with outer fore wing margin; costal area with very small, narrow green dash postmedially. Hind wing uniform pale beige; fringe somewhat darker. Underside of wing paler than upper side, both fore-and hind wing uniformly pale vermillion without markings.

Taxonomic note
In the current paper, we remove this taxon from its synonymy with D. viridiplaga and restore it to species level due to several observations. Consistent differences in the gnathos width and configuration of the distal valval processes in the male genitalia were observed, as explained under the diagnosis. Geographically, D. viridiplaga appears to be confined to an area east of the Dahomey Gap but west of the Cameroon Line, whilst D. charopa is distributed throughout the lowland Congo basin, showing an allopatric distribution. The female adult and both male and female genitalia are described here for the first time.

Description
External morphology. Female. Fore wing length 14.5-15 mm. Body and wing colour as in male but slightly paler. Antenna filiform. Fore wing broad, longer and with outer margin more evenly arcuate than in males. Green medio-ventral fascia is markedly longer and slightly broader than in males, almost parallel with outer fore wing margin; costal area with green triangular dash postmedially. Hind wing uniform pale beige; fringe somewhat darker. Underside of wing paler than upper side, both fore-and hind wing uniformly pale vermillion without markings.

Diagnosis
Based on morphology as well as genetic data, D. charopa is the closest relative of D. viridiplaga, with which it was synonymised by Hering (1928). The external morphology is very similar, with both species showing a Veronese green, narrow, elongate fore wing fascia. However, in the male genitalia of D. charopa, the gnathos is shorter, much wider, more plate-like, and squared apically compared to the longer, slimmer, apically rounded gnathos of D. viridiplaga. The valva is trilobate distally in both species, although it is broader in D. charopa, the distal dorso-apical lobe is less pointed and shorter, the medial process is shorter and the ventral process is slightly longer than in D. viridiplaga. The phallus of D. charopa is less evenly curved.
In the female genitalia, the eighth tergite of D. charopa is trapezoid with straight margins while it is postero-medially produced into a rounded lobe in D. viridiplaga. The ductus bursae of D. charopa is approximately half as long as in the related species, and the two signum bursae plates are smaller and less separated.
The comparison between D. charopa and D. ochsei can be found under the diagnosis of the latter species.

Description
External morphology. Male. Fore wing length 11-12 mm. Head, collar, tegula, and thorax vermillion, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one green circular patch. Dorsal side of thorax with two green parallel longitudinal streaks; ventral side pale beige without markings. Legs vermillion laterally, beige medially. Abdomen uniformly pale beige, first two abdominal segments with vermillion hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour vermillion, veins contrasting black in postmedial area. Medio-ventral fascia Veronese green, elongate, narrow, slightly oblique, margined with black on distal edge. Fringe long, slightly darker than ground colour. Hind wing uniformly pale ochreous with slightly darker, long fringe. Underside of wing. Both wings pale vermillion without markings; fringe same as ground colour.
Female. Fore wing length 14.5-15.5 mm. Body and wing colour as in male but much paler. Antenna filiform. Fore wing. Broad, with outer margin more evenly arcuate than in males. Green medio-ventral fascia is markedly longer and somewhat narrower than in males, almost parallel with outer fore wing margin; costal area with very small, narrow green dash postmedially. Hind wing uniform pale beige; fringe somewhat darker. Underside of wing paler than upper side, both fore-and hind wing uniformly pale vermillion without markings.

Diagnosis
This species is highly reminiscent of both D. viridiplaga and D. charopa, as all species have a relatively long and narrow green fore wing fascia. However, the three species are clearly distinct in the genital morphology. Compared with D. viridiplaga, D. ochsei has a wider valva, and the distal dorso-apical lobe is larger and more rounded whilst the medial distal process is markedly shorter and broader. In the female genitalia, the eighth tergite of D. ochsei is shorter than in D. viridiplaga, without a distal protrusion but with two small lateral processes; the ductus bursae is narrower, and the signum bursae is medially fused whilst it consists of two completely separated plates in the related species.
The male genitalia of D. ochsei are most similar to those of D. charopa, but differs in the following features. The gnathos of D. ochsei is slightly longer, distinctly narrower, and more rounded apically compared to the plate-like, quadrangular gnathos of D. charopa. In terms of the distal valval processes, the dorso-apical lobe is larger and more rounded in the new species but flatter and reduced in D. charopa. Additionally, the phallus of D. ochsei is slightly longer and slimmer than that of the allied species. Comparing the female genitalia, D. ochsei has a shorter eighth tergite with nearly straight distal margin, whilst it is trapezoidal in D. charopa, the ductus bursae is markedly longer and narrower in the new species, and the signum bursae is more elongate and medially fused.

Genetic information
This species has been assigned the BIN URI: BOLD:ABA6891/AEJ0449 (n = 6). Delorhachis ochsei has an intraspecific genetic variability of 1.09-2.20%. Its nearest neighbour is D. charopa, with a genetic divergence of 2.51-3.49%, compared to the third member of the species group D. viridiplaga from which the pairwise distance is 3.81-4.48%.

Etymology
This species has been named in honour of Dr Michael Ochse (Weisenheim am Berg, Germany), renowned lepidopterist and collector of the holotype of this new species.

Distribution and habitat (Figures 167-168, 183)
Delorhachis ochsei is found in Ghana, Guinea, Ivory Coast, Liberia, and Sierra Leone, regions characterised by both wetter and drier Guinea-Congolian rainforest. This new species and D. viridiplaga may be an example of allopatric speciation either side of the Volta River System in Ghana, a region known to act as a barrier for speciation (e.g. Sands et al. 2017). Delorhachis ochsei occurs only west of Lake Volta whilst D. viridiplaga has only been found east of this region.

Taxonomic note
A female specimen from Zambia that morphologically matched the female holotype was recovered with male specimens from Zambia in DNA barcodes, allowing us to describe the male adult and genitalia for the first time, as well as the female genitalia.

Description
External morphology. Male. Fore wing length 11.5-14.5 mm. Head, collar, tegula, and thorax vermillion, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one green rounded patch. Dorsal side of thorax with central green patch; ventral side pale beige without markings. Legs vermillion laterally, beige medially. Abdomen uniformly pale beige, first two abdominal segments with vermillion hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour vermillion, veins contrasting black in postmedial area. Medio-ventral fascia Veronese green, broad, rounded, margined with black on distal edge; costal area sometimes with very small green dash postmedially. Fringe long, slightly darker than ground colour. Hind wing uniformly pale ochreous with slightly darker, long fringe. Underside of both wings pale vermillion without markings; fringe same as ground colour.

Diagnosis
Based on genital morphology, D. chlorodaedala is the closest relative of D. kitale but is distinguished by the following external features: the ground colour is vivid vermillion and the fore wing fascia is markedly wider, reaching the base of the cell, whilst the ground colour is more brownish and the fore wing fascia is much paler and smaller, ending at vein CuP in D. kitale. In the male genitalia of D. chlorodaedala, the gnathos is considerably narrower, forming a highly sclerotised, elongate triangular, apically rounded, more or less inverse V-shaped plate, whereas it is postmedially tapered, apically produced into a short, rounded process in the allied species. The phallus of D. chlorodaedala is straight, somewhat shorter and thicker than the medially curved phallus of D. kitale.

Genetic information
This species belongs to the BIN URI: BOLD:AEL2356 (n = 9). The intraspecific variation of D. chlorodaedala ranges from 0.00% to 2.51%. Its nearest neighbour is D. pallidifascia, at a distance of 5.93-6.45%. The genetic distances from other members of the species group are as follows: D. meyi diverges at 6.97-7.68%, and D. parvinota at 6.11-6.62%.

Distribution and habitat (Figures 169-171, 184)
This species was previously known from Angola, and our research has found it to also exist in the DRC, Malawi, Tanzania and Zambia. The distribution of these specimens suggests its range extends to the highland region of the Bié and Zambian plateaus, and across the Rift Valley onto the Uzondo plateau of West Tanzania; these regions are characterised by wetter Zambezian miombo woodland. West, 1940 (Figures 13-15, 73, 99-

Taxonomic note
A single specimen from Sudan (gen. slide no. 2021.838, RCRF) was found to have very similar genitalia to D. kitale, differing only slightly in the size of the distal processes of the valva. However, due to the identical habitats and the lack of a clear biogeographic barrier between Kadugli and Lodara (where a true D. kitale specimen was collected), it is highly likely that the Sudanese specimen is conspecific with D. kitale, displaying only a minor divergence in the male genital structure. The male genitalia of D. kitale is described here for the first time.
Gnathos subapically tapered, thin and rounded at apex. Juxta rounded basally, with two short, ventral, ribbon-like distal processes; manica with bunch of inordinately curved, moderately long pseudocornuti. Vinculum short and broad, rounded. Valva slightly constricted medially, largely dilated into two broad processes distally, forming a triangular, apically rounded dorso-apical process, and a shorter, rounded ventral process. Phallus long, thin, medially slightly bent with sclerotised, apically pointed ventral surface in its basal half. Vesica membranous without cornuti.

Diagnosis
Comparison with the closest species is discussed under the diagnosis of D. tommasoi sp. nov.

Genetic information
No specimens of D. kitale suitable for DNA barcoding were accessed during this study.

Distribution and habitat (Figure 184)
Delorhachis kitale was previously only known from the deciduous bushland and thicket region of western Kenya, but has now been identified from the drier rainforest-grassland mosaic of eastern DRC and Uganda, and the Sudanian woodlands of South Sudan, representing new country records.

Description
External morphology. Male. Fore wing length 11.5-14 mm. Head, collar, tegula, and thorax vermillion, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one green rounded patch. Dorsal side of thorax with central green patch; ventral side pale beige without markings. Legs vermillion laterally, beige medially. Abdomen uniformly pale beige, first two abdominal segments with vermillion hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour vermillion, veins contrasting black in postmedial area. Medio-ventral fascia Veronese green, relatively large, rounded, margined with black on distal edge. Fringe long, slightly darker than ground colour. Hind wing uniformly pale ochreous with slightly darker, long fringe. Underside of both wings pale vermillion without markings; fringe same as ground colour.

Female. Unknown.
Male genitalia. Uncus short, tapered, apically pointed. Tegumen broad. Gnathos medially tapered into a narrow postmedial section, then slightly dilated and rounded apically. Juxta rounded basally, with two very short, ventral, ribbon-like distal processes; manica with a bunch of moderately short sclerotised, slightly curved pseudocornuti. Vinculum short and broad, rounded. Valva slightly constricted medially, largely dilated into two broad, curved processes distally, with a pointed dorso-apical process, and a slightly shorter, rounded ventral process. Phallus relatively short, straight with sclerotised, apically pointed ventral surface in its basal half. Vesica membranous without cornuti.

Diagnosis
Delorhachis tommasoi is the closest relative of D. kitale. Externally, the new species has somewhat larger, more rounded, green medio-ventral fascia. The ground plan of the male genitalia is nearly identical; however, the following diagnostic characters are noted: in the new species, the gnathos is markedly narrower, tapering medially with a longer, narrower apical portion and a slightly bulbous, completely rounded apex compared to the shorter, less rounded distal portion of the gnathos in the related species. The pseudocornuti of D. tommasoi are more uniform in shape compared with D. kitale, and the valva is markedly wider distally with more curved processes of which the dorso-apical process is only slightly longer than the ventral one, unlike in D. kitale where the dorso-apical process is straight and markedly longer than the ventral one. The phallus of the new species is also much shorter than that of the allied species.

Genetic information
Due to the age of the accessed specimens, this species was not sampled for DNA barcoding.

Etymology
This species was named in honour of Tommaso Giusti, nephew of the third author of this paper. Tommaso is a young student of biotechnologies at the University of Pisa, and a lover of the natural world.

Distribution and habitat (Figure 184)
Recorded so far only from the DRC, D. tommasoi inhabits the lowland, swampy rainforest of the Congo Basin, although the southernmost extent of its range is characterised by slightly drier Guinea-Congolian rainforest. Taberer

Description
External morphology. Male. Fore wing length 11-13.5 mm. Head, collar, tegula, and thorax vermillion, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one cream or green rounded patch. Dorsal side of thorax with a central cream or green patch; ventral side pale beige without markings. Legs vermillion laterally, beige medially. Abdomen uniformly pale beige, first two abdominal segments with vermillion hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour vermillion, veins contrasting black in postmedial area. Medio-ventral fascia cream, relatively small, rounded, margined with black on distal edge. Fringe long, slightly darker than ground colour. Hind wing uniformly pale ochreous with slightly darker, long fringe. Underside of both wings pale vermillion without markings; fringe same as ground colour.
Female. Fore wing length 14.5 mm. Body and wing colour as in male. Antenna filiform.
Fore wing broad with outer margin more evenly arcuate than in males. Pale green medioventral fascia is markedly longer and somewhat narrower than in males, almost parallel with outer margin; costal area with cream patch postmedially. Hind wing uniform pale beige; fringe somewhat darker. Underside of wing paler than upper side, both fore-and hind wing uniformly pale vermillion without markings.

Diagnosis
Based on external morphology, D. pallidifascia is the closest kin of D. kitale, although the fore wing fascia of the new species is lighter, cream coloured. In male genitalia, the gnathos is markedly broader and more sclerotised compared with D. kitale, the valva is slightly thicker with a wider ventral process, and the pseudocornuti are more uniform in shape in the new species.
Based on the configuration of the female genitalia, D. pallidifascia is most similar to D. chlorodaedala but readily distinguished by the quadrangular eighth tergite (it is trapezoidal in the related taxon) and the much less swollen ductus bursae lacking any loose cornuti. The signum bursae of the new species is formed of two medially fused bellshaped plates, whilst in D. chlorodaedala it consists of two semi-circular separated plates.

Genetic information
The new species is assigned the BIN URI: BOLD:AEJ8189 (n = 2). The intraspecific variation of D. pallidifascia is 0.15%. It was recovered in a sister clade to D. parvinota and D. meyi, and is closest genetically to D. parvinota, with a pairwise distance of 3.82-3.92%. Delorhachis pallidifascia differs from D. meyi by 4.15-4.31%, and from D. chlorodaedala by 5.93-6.45%.

Etymology
The species name is in reference to its pale (pallidus in Latin) green fore wing fascia.

Taxonomic note
The male genitalia of D. mariae are described here for the first time.
Gnathos broad, ovoid, rounded apically. Juxta rounded basally, with two short, ribbonlike distal processes; manica with a bunch of moderately long, sclerotised, curved pseudocornuti. Vinculum short and broad, rounded. Valva relatively narrow at base, slim, long, without medial constriction, dilated into two processes distally, with a longer, curved, distally rounded dorso-apical process, and a reduced, extremely short ventral process. Phallus medially slightly bent, bearing a sclerotised, apically pointed ventral surface in its basal half. Vesica membranous without cornuti.

Diagnosis
Externally, D. mariae is most reminiscent of D. kitale, but differs in the slightly smaller rounded fore wing fascia. In terms of the male genitalia, the general ground plan is very similar in the two species, although in D. mariae the gnathos is broad and rounded whilst in D. kitale it is apically produced into a rounded process. The valva of D. mariae is markedly narrower, not constricted medially, and with a much shorter ventral process compared to the related species. In addition, the pseudocornuti of D. mariae curve uniformly whilst in the related species they curve inordinately. Delorhachis mariae also has a markedly shorter coecum penis than D. kitale.
Compared with D. tommasoi, D. mariae is very similar externally except for the slightly smaller fore wing fascia. In the male genitalia, however, the differences are clearly expressed by the following features: the gnathos of D. mariae is much broader and more rounded compared to the narrower, tapered, and apically rounded gnathos of D. tommasoi. Additionally, the valva of D. mariae is slimmer and more even in width, with more rounded distal processes comprised of a longer, straighter dorso-apical process and a significantly shorter, highly reduced ventral process compared to those of D. tommasoi.

Genetic information
No specimens of D. mariae were available for DNA barcoding.

Distribution and habitat (Figure 184)
This species was only identified from South Kivu in the DRC but has now also been found from southern Malawi, representing a new country record. Delorhachis mariae inhabits the lowland rainforest of the Congo Basin as well as the densely forested slopes of Mount Mulanje in Malawi. Taberer

Description
External morphology. Male. Fore wing length 11.5-13 mm. Head, collar, tegula, and thorax vermillion, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one green rounded patch. Dorsal side of thorax with a central green patch; ventral side pale beige without markings. Legs vermillion laterally, beige medially. Abdomen uniformly pale beige, first two abdominal segments with vermillion hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour vermillion, veins contrasting black in postmedial area. Medio-ventral fascia Veronese green, very small, rounded, margined with black on distal edge. Fringe long, slightly darker than ground colour. Hind wing uniformly pale ochreous with slightly darker, long fringe. Underside of both wings pale vermillion without markings; fringe as ground colour.
Female. Fore wing length 14.5-15.5 mm. Body and wing colour as in male. Antenna filiform. Fore wing. Broad with outer margin more evenly arcuate than in males. Green medio-ventral fascia is markedly longer than in males, narrow, almost parallel with outer fore wing margin; costal area with very small, narrow green dash postmedially. Hind wing uniform pale beige; fringe somewhat darker. Underside of wing paler than upper side, both fore-and hind wing uniformly pale vermillion without markings.

Diagnosis
Externally, the new species is most reminiscent of D. mariae due to the small, rounded, green fore wing fascia. Their male genitalia are also fairly similar, however, noticeable differences can be seen in the following features: the uncus of the new species is narrower and slightly longer, and the gnathos is tapered whilst it is larger and apically rounded in D. mariae. The valva of D. parvinota is slightly narrower, possessing a much thinner, longer and rather claw-like dorso-apical process, and a much longer ventral valval process compared to D. mariae. The pseudocornuti of the new species are strongly curled, and the phallus is slightly shorter than in the allied species.
Comparing the female genitalia with those of D. chlorodaedala, the eighth tergite of D. parvinota is more tapered and the antevaginal plate is more heavily sclerotised and wrinkled.
The new species has a considerably shorter and narrower ductus bursae without a swollen section containing loose cornuti, a shorter and thicker tubular part of corpus bursae, and a somewhat larger and more elongate signum bursae compared with D. chlorodaedala.

Genetic information
This species has been assigned the BIN URI: BOLD:AEJ9364 (n = 1). The intraspecific variation could not be calculated as only one specimen was sequenced for DNA. Delorhachis parvinota was recovered as a sister species to D. meyi, with 3.33% pairwise distance. In terms of D. pallidifascia, which represents a sister clade, D. parvinota shows a genetic distance of 3.82-3.98%. Finally, the pairwise distance between D. parvinota and D. chlorodaedala was 6.11-6.62%.

Etymology
The name of this species is an aggregate of the Latin 'parvus' meaning 'small' and 'nota' meaning 'marked', in reference to the noticeably small, rounded fore wing fascia which distinguishes it from its congeners. (Figures 172-174, 184) Currently known from Ivory Coast, Liberia and Sierra Leone, this species exists within the Upper Guinean Rainforest although its westernmost distribution is characterised by a mosaic of lowland rainforest and secondary grassland.

Description
External morphology. Male. Fore wing length 11-14 mm. Head, collar, tegula, and thorax vermillion, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one green rounded patch. Dorsal side of thorax with a central green patch; ventral side pale beige without markings. Legs vermillion laterally, beige medially. Abdomen uniformly pale beige, first two abdominal segments with vermillion hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour vermillion, veins contrasting black in postmedial area. Medio-ventral fascia Veronese green, very broad, rounded, margined with black on distal edge. Fringe long, slightly darker than ground colour. Hind wing uniformly pale ochreous with slightly darker, long fringe. Underside of wing. Both wings pale vermillion without markings; fringe as ground colour.
Female. Fore wing length 15-16 mm. Body and wing colour as in male. Antenna filiform.
Fore wing broad with outer margin more evenly arcuate than in males. Green medioventral fascia is markedly longer and slightly narrower than in males, almost parallel with outer fore wing margin; costal area with triangular green dash postmedially. Hind wing uniform pale beige; fringe somewhat darker.

Diagnosis
The comparison between D. meyi and D. parvinota is provided under the diagnosis of the latter species.
The new species is also reminiscent of D. chlorodaedala but distinguished by the somewhat larger size and slightly larger fore wing fascia with a broader base. In the male genitalia, D. meyi has a broader and less pointed gnathos, more curved pseudocornuti of manica, markedly narrower and medially more constricted valva with a considerably longer and narrower, more pointed, less curved dorso-apical process. The phallus of the new species is much shorter, less tapering, with markedly shorter coecum than in D. chlorodaedala.
Compared to D. parvinota, D. meyi, is bigger in size with a larger body, and the fore wing fascia is considerably larger and broader. In the male genitalia, they are rather similar, although D. meyi has a slimmer and apically less tapered gnathos, less curled pseudocornuti, and valva with less curved and thicker dorso-and more pointed ventro-apical processes. In the female genitalia, the antevaginal plate of D. meyi is much smaller, smoother and somewhat more heavily sclerotised than that of D. parvinota. The ductus bursae is similarly short in both species, but the tubular part of the corpus bursae is substantially wider in D. meyi than in D. parvinota. Finally, the signum bursae of D. meyi is smaller and semi-circular in shape, compared to the larger, amorphous signum of the related species.

Genetic information
This species belongs to the BIN URI: BOLD:AEO1351. As only one specimen was sampled for DNA barcoding, no data of intraspecific variation can be provided. The nearest neighbour to D. meyi is D. parvinota, with 3.33% pairwise distance between the two species. The genetic divergence of D. parvinota from D. pallidifascia and D. chlorodaedala was 4.15-4.30% and 6.97-7.68%, respectively.

Etymology
Delorhachis meyi is named in honour of the collector of the holotype, Wolfram Mey, former collection manager of the MfN, Berlin, renowned specialist of Microlepidoptera and Trichoptera. (Figures 175-176, 184) Delorhachis meyi inhabits the rainforest and secondary grassland mosaic region of Uganda and Kenya, although the locality data suggests that this is a forest-dwelling species.

Description
Male external morphology. Fore wing length 13.5 mm. Head, collar, tegula, and thorax vermillion, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one green rounded patch. Dorsal side of thorax with a central green patch; ventral side pale beige without markings. Legs vermillion laterally, beige medially. Abdomen uniformly pale beige, first two abdominal segments with vermillion hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour vermillion, veins contrasting black in postmedial area. Medio-ventral fascia pale green, narrow, elongate, undulate, margined with black on distal edge. Fringe long, slightly darker than ground colour. Hind wing uniformly pale ochreous with slightly darker, long fringe. Underside of both wings pale vermillion without markings; fringe as ground colour.

Diagnosis
Delorhachis wetzelae is most similar in size to D. meyi, although the former species has a lighter green, narrower, undulating fore wing fascia compared to the broader fascia of the latter species. The male genitalia of D. wetzelae has a somewhat shorter gnathos, less numerous and straighter pseudocornuti, and a medially somewhat narrower valva with a shorter, more curved, less pointed dorso-apical process compared to those of D. meyi.

Genetic information
The single known specimen of D. wetzelae was not suitable for DNA barcoding due to its age.

Etymology
Delorhachis wetzelae is named in honour of Ellen Wetzel, Arten-Schönfeld, Germany, for her contribution to entomological research.

Distribution and habitat (Figure 184)
This species is presumably endemic to the forested Uluguru Mountains of the Eastern Arc Mountains in Tanzania. An allopatric sister taxon of D. wetzelae was found from the nearby Usambara Mountains and is described below as D. wetzelae shambaa ssp. nov.

Description
External morphology. Male. Fore wing length 12-13.5 mm. Head, collar, tegula, and thorax vermillion, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one green rounded patch. Dorsal side of thorax with a central green patch; ventral side pale beige without markings. Legs vermillion laterally, beige medially. Abdomen uniformly pale beige, first two abdominal segments with vermillion hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour vermillion, veins contrasting black in postmedial area. Medio-ventral fascia pale green, narrow, elongate, undulate, margined with black on distal edge. Fringe long, slightly darker than ground colour. Hind wing uniformly pale ochreous with slightly darker, long fringe. Underside of both wings pale vermillion without markings; fringe same as ground colour.

Diagnosis
The two subspecies of D. wetzelae are hardly distinguishable externally; however, the following differences in the male genitalia have been noted: the subspecies from Usambara has a markedly wider and somewhat shorter valva, with more pointed distal processes compared to D. wetzelae. Also, D. w. shambaa has a tapered, triangular gnathos whilst the other species has a gnathos that medially constricts, and the pseudocornuti of the ssp. shambaa are more numerous, slightly longer and straighter.

Taxonomic note
Although the external morphology of D. wetzelae and D. w. shambaa is nearly identical, the combination of minor genitalia differences and their allopatric distribution suggested the presence of two taxa and hence the populations of the Usambara and Uluguru Mountains are distinguished here as distinct subspecies (see Distribution and habitat for more information on their allopatry).

Genetic information
Due to the age of the accessed specimens, there was no barcode data available for D. w. shambaa.

Etymology
The subspecies name is in recognition of the Shambaa people, one of the main ethnic groups that has historically inhabited the Usambara Mountains of Tanzania.

Distribution and habitat (Figure 184)
This subspecies only occurs in the Usambara Mountains in Tanzania. The Eastern Arc Mountains, comprising a chain of isolated hills and mountains across Kenya and Tanzania, forms a centre of endemism for vertebrates (Rovero et al. 2014), invertebrates (Scharff 1992) and plants (Temu and Andrew 2008). Reviews by Wasser and Lovett (1993) and Burgess et al. (1998) have found that up to 80% of the invertebrate fauna of a single mountain in this region can be strictly endemic, providing high levels of localised biological richness. Despite this, little work on the Lepidoptera of the Eastern Arc has been carried out (see Congdon et al. 2001;de Jong and Congdon 1993); thus, further studies would be beneficial to understand the distribution of D. wetzelae and related subspecies, contributing to the knowledge of the biogeography of this specialised region.

Taxonomic note
Here, we describe the male genitalia for the first time.
Gnathos very broad, weakly sclerotised, rounded. Juxta very short and rounded, with two short, ventral, ribbon-like distal processes; manica with a bunch of straight, relatively short pseudocornuti. Vinculum very short, rounded. Valva broad, triangular, wide at base, narrowing distally, with a small rounded distal process. Phallus medium-long, thin, medially very slightly bent with sclerotised, apically pointed ventral surface in its basal half. Vesica membranous without cornuti.

Diagnosis
A detailed diagnosis can be found under D. zambica sp. nov.

Genetic information
Delorhachis kilosa was not sampled for DNA barcoding. (Figure 185) This species was described from the Rubeho Mountains in central Tanzania, and our research has also found it from the Kigoma Region in north-west Tanzania and from the Mangochi Hills in southern Malawi, representing a new country record. These regions are characterised by both wet and dry Zambezian miombo woodland. A publication by Vári et al. (2002) reports D. kilosa from South Africa. The checklist of the South African Lepidoptera does not illustrate the taxa listed, and the specimen, which is presumably deposited in the Ditsong Museum, Pretoria, was not accessed by the authors of this paper. It is therefore unclear whether D. kilosa occurs in South Africa; however, this is highly unlikely considering its known distribution. A more plausible explanation would be that the specimen identified by Vári et al. (2002) was actually D. zambica sp. nov., which could possibly be found in the north-east, upland region of South Africa; nevertheless, without knowing any further locality or morphological data, this record is inconclusive. Taberer,Fiebig,83,154) Holotype

Description
Male external morphology. Fore wing length 10-11.5 mm. Head and collar bright orange, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Thorax and tegula uniformly chestnut brown dorsally, with a white longitudinal streak posterior-medially. Legs bright orange. Abdomen bright orange dorsally, yellowish laterally and brownish ventrally. Fore wing short, broad, triangular, with rounded apex; ground colour rusty-brown, veins contrasting black in postmedial area. Medio-ventral fascia white, circular or oval-shaped, margined with black on both proximal and distal edge. Fringe long, slightly darker than ground colour. Hind wing pale brown with beige area along anal margin, veins sometimes highlighted with brown. Underside of wing: fore wing light brown, hind wing beige without markings, fringe same as ground colour.
Gnathos very broad, weakly sclerotised, rounded. Juxta very short and rounded with two short, ventral, ribbon-like distal processes; manica with a bunch of numerous, fine, relatively short, straight pseudocornuti. Vinculum short, rounded. Valva moderately broad, triangular, with more or less straight margins, apex with very small rounded distal process. Phallus medium-length, thin, medially very slightly bent, with sclerotised, apically pointed ventral surface in its basal half. Vesica membranous without cornuti.

Diagnosis
This species is a closely related allopatric sibling of D. kilosa, showing only minor differences in the genital morphology, expressed by the slightly longer and slimmer valva of D. zambica. Despite the high similarity in the male genitalia, the distinctive features are obvious in external morphology where the fore wings and abdomen are a deeper brown in D. zambica, and the abdomen possesses a wider longitudinal white streak compared to D. kilosa. The fore wing fascia of the new species is larger, white, and circular or ovoid, whilst in D. kilosa this feature is smaller, cream to Veronese green, and triangular.

Genetic information
This species was not sampled for DNA barcoding.

Etymology
The species name is in reference to Zambia, where the species is most abundant, inhabiting the extensive Miombo woodlands of the Zambian Plateau.

Distribution and habitat (Figures 169, 185)
Delorhachis zambica has been found from south DRC, Malawi and Zambia, in areas dominated by miombo and scrub woodland. It appears to be separated from D. kilosa by the western branch of the Rift Valley, a biogeographic barrier inducing allopatric speciation which has seemingly driven noticeable divergences in external morphology of the two species but less so in male genitalia. Further genetic studies are required to assess the genetic divergence between these sibling species.

Taxonomic note
This species has here been assigned to Delorhachis due to certain shared characters typical of the genus, namely a medio-ventral fore wing fascia, black veins in the postmedial area of the fore wing, a coloured patch on the tegula, and the presence of pseudocornuti on the manica. The genetic analyses also revealed a close kinship to other lineages, whilst clearly forming a distinct clade with D. smithi sp. nov. The male genitalia are described here for the first time.
Gnathos very broad, rounded, shield-like, apically with short rounded process. Juxta short, rounded basally, with two short, ventral, ribbon-like distal processes; manica with a bunch of slightly curved, relatively short pseudocornuti. Vinculum broad, rounded. Valva long, triangular, distally rounded with a very small, rounded ventral process. Phallus long, thin, evenly slightly curved, with sclerotised, apically pointed ventral surface in its basal half. Vesica membranous without cornuti.

Diagnosis
The distinctive features of D. syntomoctena are discussed under the diagnoses of the other members of the species group.

Genetic information
This species has been assigned the BIN URI: BOLD:AEK5448 (n = 2). The infraspecific variability of D. syntomoctena is 0.15%. The nearest neighbour of this species is D. smithi, differing by a pairwise distance of 6.84-7.01%.

Distribution and habitat (Figure 186)
This species has only been found in east DRC, on the furthermost eastern edge of the lowland Congolian rainforest.

Description
Male external morphology. Fore wing length 13 mm. Head, collar, and tegula yelloworange to yellow-beige, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one white rounded patch. Thorax ochreous brown to beige dorsally, yellow ventrally. Legs yellow. Abdomen yellow-orange to light beige dorsally, yellow ventrally, first two segments with ochreous brown to beige hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour ochreous brown to light beige, veins contrasting black in postmedial area. Medio-ventral fascia white, oval, narrow, strongly directed inwards, margined with black on distal edge. Fringe long, colour as ground colour. Hind wing uniformly light brown to pale beige, with black veins postmedially. Underside of wing: fore wing pale brown to pale beige, hind wing yellow-beige to pale beige without markings; fringe as ground colour.
Juxta with a v-shaped moderately sclerotised basal section, with two relatively short, heavily sclerotised distal processes; manica with a bunch of straight pseudocornuti varying in width and length. Vinculum long, broad, rounded. Valva wide at base, abruptly constricted medially, very narrow distally without dorso-apical process and with very short, thin, upcurved and pointed ventral process. Phallus long, narrow, medially slightly bent with sclerotised, apically pointed ventral surface in its basal half. Vesica membranous without cornuti.

Diagnosis
This species is closest to D. syntomoctena in terms of adult morphology, but is generally lighter in colour. In the male genitalia, the following notable differences are observed: the gnathos is broad in both species but in D. manuelae sp. nov. it is M-shaped with two short rounded distal lobes whilst in D. syntomoctena the gnathos has a single short, rounded apical process. Delorhachis manuelae has a valva which is strongly constricted medially, with a narrow distal half, whilst the valva of D. syntomoctena tapers gradually and is triangular in shape. At the distal portion of the valva, the new species lacks dorso-apical process and has a short, curved, narrow, pointed ventral process, whilst in the related species, the dorsal process is well developed and the ventral process is very small and rounded. Delorhachis manuelae also possesses a shorter phallus than D. syntomoctena.

Genetic information
Due to the age of the accessed specimens, this species has not been sampled for DNA barcoding.

Etymology
Delorhachis manuelae is named in honour of Manuela Windisch, München, Germany, for her contribution to entomological research.

Distribution and habitat
This species has only been found from the northern part of the Republic of the Congo, a region generally characterised by lowland wet Guinea-Congolian rainforest. However, it is worth noting that Odzala has an incredibly unique and rich savannah fauna as well, although it is difficult to establish which of these habitats this species is associated with based on the label data.

Description
External morphology. Male. Fore wing length 12.5 mm. Head, collar, and tegula yelloworange, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one cream-white rounded patch. Thorax ochreous brown to beige dorsally. Abdomen yellow-orange dorsally, first two segments with ochreous brown to beige hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour ochreous brown, veins contrasting black in postmedial area. Medio-ventral fascia white, oval, margined with black on distal edge. Fringe long, slightly darker than ground colour. Hind wing uniformly light brown, veins black from medial to distal portion.
Gnathos broad, weakly sclerotised, with two short, rounded distal lobes with a shallow medial depression. Juxta with two moderately long, heavily sclerotised distal processes; manica with a cluster of short, straight pseudocornuti. Vinculum relatively long, broad, rounded. Valva very wide at base, tapered, distally with a short, rounded dorso-apical process and a slightly longer, rounded ventral process. Phallus long, narrow, medially slightly bent with sclerotised, apically pointed ventral surface in its basal half. Vesica long, tubular, membranous without cornuti.

Diagnosis
Externally, this species is reminiscent of D. syntomoctena, although the fore wing fascia in the new species is wider and more rounded, compared to the very narrow, ovoid fore wing fascia of the related species. In the male genitalia, however, the differences are obvious: the gnathos of D. bakossii sp. nov. has a shallow, medial depression at the apex compared to the pointed apex in the gnathos of the allied species. Also, the distal portion of the valva in the new species has a shorter, rounded dorso-apical process, and a slightly longer ventral process compared to those of D. syntomoctena.
In terms of the male genitalia morphology, this species is closest to D. manuelae due to the valva being very broad at the base and curved ventrad, but distinguished by the much wider distal section and the broader apex of the valva, as well as the apically less deeply depressed gnathos and the slightly shorter pseudocornuti in D. bakossii.

Genetic information
No DNA barcodes were available for this species.

Etymology
The species is named after the Bakossi, a West African ethnic group based in south-west Cameroon. The settlement area of the Bakossi includes the Bakossi Mountains, the type locality of the species. (Figures 180-181, 186) This new species has so far only been recorded from the Bakossi Mountains of southwestern Cameroon, a mountainous rainforest region which makes up part of the Cameroon Line.

Description
Male external morphology. Fore wing length 11-13 mm. Head, collar, tegula, and thorax yellow-brown, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one white rounded patch. Thorax yellow-brown dorsally, beige ventrally. Legs beige. Abdomen uniformly beige, first two segments with yellow-brown hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour pale yellowish-brown, veins contrasting black in postmedial area. Medio-ventral fascia white, broad, oval, slightly directed inwards, margined with black on distal edge; costal area sometimes with small, diffused white patch postmedially. Fringe long, slightly paler than ground colour. Hind wing uniformly buff, with weakly defined black veins from medial to distal portion. Underside of oth fore wing and hind wing buff without markings; fringe same as ground colour.

Diagnosis
Delorhachis smithi is reminiscent externally of D. syntomoctena, but differs in the following features: the thorax and wings are paler, the tegula patch is lighter, and the head and abdomen are less vivid yellow in D. smithi compared with D. syntomoctena. The medial fascia of both species is white, although in the new species, it is much broader than in D. syntomoctena, and the black veins on the hind wing of D. smithi are less sharply defined compared with the related species.
In the male genitalia, the gnathos of D. smithi is broadly rounded apically whilst in D. syntomoctena the gnathos possesses a short, rounded triangular, apical process. The valva of the new species is markedly narrower, with much longer, thinner, and more pointed distal processes where the dorso-apical process is shorter than the ventral, compared to the broader, triangular valva of D. syntomoctena whereby the processes are much thicker, distally rounded, and the dorso-apical process is longer than the barely noticeable ventral one. The pseudocornuti of the manica are slightly more curved in D. smithi, and the phallus is shorter and straighter compared with the allied species.
Compared to D. manuelae, the new species has a much broader, rounded medial fascia. In the male genitalia, the gnathos of D. smithi is rounded without an apical depression (it is medially deeply incised in D. manuelae), and the valva is considerably narrower and more elongate, with much longer apical processes. The pseudocornuti of D. smithi are also markedly longer and more curved than in the related species.
In comparison to D. bakossii, D. smithi has a paler ground colour, a slightly larger fore wing fascia and a less striate hind wing. The male genitalia of D. smithi has a conspicuously narrower valva, with much longer, narrower, more pointed apical processes than in the allied species. The pseudocornuti are also noticeably longer in D. smithi.

Genetic information
This species has been assigned the BIN URI: BOLD:AEK3851 (n = 1). As only one specimen of D. smithi was barcoded, intraspecific variation could not be calculated. The pairwise distance between the new species and D. syntomoctena is 6.84-7.01%.

Etymology
This new species is dedicated to Richard Smith, founder and Chairman of the Board of Trustees of the African Natural History Research Trust.

Distribution and habitat (Figures 177, 186)
This species has been found in Gabon and the northern region of the Republic of the Congo, a continuous area of wet Guinea-Congolian lowland rainforest. Taberer

Description
External morphology. Male. Fore wing length 11.5-12 mm. Head, collar, tegula, and thorax brown, antenna bipectinate in basal fourth, otherwise filiform, yellow-brown. Tegula with one pale yellow rounded patch. Thorax dark chestnut brown dorsally, ventral side and legs yellowish-brown. Abdomen uniformly brown dorsally and yellowish brown ventrally. Fore wing short, broad, triangular, with rounded apex; ground colour chestnut brown, veins contrasting black in postmedial area. Medio-ventral fascia white, oval, directed inwards, margined with black on distal edge. Fringe long. Hind wing chestnut brown, with weakly defined dark brown veins postmedially. Underside of both wing sets pale brown without markings; fringe as ground colour.
Gnathos large, very broad, rounded, shield-like, weakly sclerotised, distal section very finely setose with a shallow medial indent. Juxta short, rounded basally, with two short, ventral, ribbon-like distal processes; manica with a bunch of slightly curved moderately long pseudocornuti. Vinculum short, broad, rounded. Valva long, very narrow, distally with a pointed, curved dorso-apical process and a slightly longer, narrow, thin, pointed, curved ventral process. Phallus long, straight, with sclerotised, apically pointed ventral surface in its basal half. Vesica membranous without cornuti.

Diagnosis
Based on the configuration of the male genitalia, this new species and D. smithi form a species pair, distinguished from other members of the species group by the extremely long, narrow valva with elongate, thin, apical processes.
Delorhachis nimbaensis is distinguished externally from its sister species by its much darker ground colour. In terms of the male genitalia, D. nimbaensis has a longer, slightly broader gnathos, and a straighter valva with a markedly shorter dorso-apical process, as well as having a wider angle between the apical processes than in the related species.

Genetic information
No specimens of D. nimbaensis were DNA barcoded.

Etymology
Delorhachis nimbaensis is named after the Nimba Mountains, Liberia, where it is assumed to be endemic.

Description
External morphology. Male. Fore wing length 13-13.5 mm. Head, collar, and tegula yellow-brown, antenna bipectinate in basal fourth, otherwise filiform, colour as of head. Tegula with one pale green rounded patch. Thorax uniformly ochreous-brown dorsally. Abdomen pale orange-brown dorsally, first two segments with ochreous-brown hair scales. Fore wing short, broad, triangular, with rounded apex; ground colour ochreous-brown, veins contrasting black in postmedial area. Medio-ventral fascia pale green, oval-shaped, margined with black on distal edge. Fringe long, colour as ground colour. Hind wing uniformly buff.

Diagnosis
This species is closest externally to D. smithi due to the buff hind wing and the similarly rounded medial fore wing fascia, although in D. baaka sp. nov. the fore wings are darker in colour, and the tegula patch and fore wing fascia are pale green as opposed to the white markings of D. smithi. In the male genitalia, the uncus of D. baaka is considerably shorter, broader, and more rounded apically, and the gnathos is more strongly sclerotised and more quadrangular compared to the allied species. The valva of D. baaka is much wider basally, and the distal portion lacks a ventral process, whilst in D. smithi the valva is narrower and possesses a very narrow, long, pointed ventral process.
Compared to D. nimbaensis, D. baaka has ochreous-brown fore wing ground colour in contrast to the chestnut brown colouration of the related species. The hind wing of D. baaka is buff, whereas it is chestnut brown in D. nimbaensis. In addition, the tegula and fore wing patches of D. baaka are pale green compared with the white patches of the allied species. In the male genitalia, the uncus of D. baaka is shorter and broader, the gnathos is narrower and more quadrangular, the pseudocornuti are considerably longer and more curved, and the valva is markedly wider basally, lacking a ventro-apical process.

Genetic information
No D. baaka specimens were sampled for DNA barcoding.

Etymology
This species name is dedicated to the Baaka ethnic group inhabiting the southern rainforests of Cameroon, from which the holotype was collected. (Figures 178-179, 186) This species has only been identified from the Guinea-Congolian wet rainforest of south Cameroon.

Taxonomic note
Miresa strigivena is here synonymised with Delorhachis nigrivenosa for the following reasons: M. strigivena was described from only a female holotype, and although paler in colour than other Delorhachis species, it shows similarly variable morphology to that in other species of the genus. Dissections of paler ('Miresa strigivena') and darker ('Delorhachis nigrivenosa') male specimens found no differences in genital morphology, and no clear genetic distinction was detected. Furthermore, DNA barcoding of a female specimen identical to the holotype of M. strigivena was recovered with both pale and darker male specimens. These species are thus considered synonymous, with variation in colouration from pale cream to beige. The male and female genitalia of D. nigrivenosa are described here for the first time.

Genetic information
Delorhachis nigrivenosa has been assigned 5 BIN URIs: BOLD:AAH6399/AEK5162/5161/ 5446/ACM8517. This species has a remarkably high infraspecific variation in DNA barcodes, ranging between 0.15% and 5.98%. Despite this large genetic variability, no clear biogeographical or morphological patterns were found that could allude to the potential of further taxa. For instance, the genetic variability within populations from southern Ivory Coast ranges from 0.46% to 3.79% in this species. It has thus been concluded here that D. nigrivenosa is a widespread species that is highly diverse in morphological as well as genetic features, which may indicate a very early stage of speciation. (Figures 182, 187) This species was earlier identified from Cameroon, Ivory Coast, Nigeria, and Togo. Our research has also found it in Central African Republic, the Republic of the Congo, the DRC, Gabon, Ghana, Guinea, Liberia, Senegal, Sierra Leone, and South Sudan, representing new country records. Delorhachis nigrivenosa occurs in both wetter and drier types of the Guinea-Congolian lowland rainforest, although it does not inhabit the central swamp forests of the Congo basin. At the northernmost extent of its range, the habitat is dominated by a slightly drier mosaic of lowland rainforest and secondary grassland, as well as Sudanian woodland in some regions.

Taxonomic note
This species has been transferred here from Delorhachis to Miresa (see Taxonomic note under M. purpurea). Its morphology is dissimilar to that of D. viridiplaga and other species in this genus, and it was likely placed in the genus by mistake due to possessing a small yellow medio-ventral fore wing fascia, which is characteristic of Delorhachis, although in M. amator this spot is extremely diffuse and lacks definition. The dissection of genitalia of the holotype shows that the valva is very elongate and without the typical distal modification of Delorhachis, and also the manica lacks pseudocornuti as seen in every member of the genus. (Hering, 1928) (Hering, 1928)

Taxonomic note
Delorachis denisae and Chrysamma erythrochrysa are here synonymised with D. purpurea. Due to their identical morphology, these three names refer to the same taxon characterised by a median orange band on the fore wing and orange fringe of both wing sets, without distinctive characters in the male genitalia. Two of the three species were described from Kivu, DRC, and the third from Lolodorf, Cameroon. We believe the species to be widely distributed in East, West, and Central Africa.
Delorhachis amator Hering, 1928, D. amica Hering, 1928, and D. purpurea Hering, 1928 are here transferred from the genus Delorhachis to Miresa (= M. amator (1928) comb. nov., M. amica (Hering, 1928) comb. nov., and M. purpurea (Hering, 1928) comb. nov.). The male genitalia ground plan of these species was found to be most similar to the African species M. gliricidiae, wherein the gnathos is composed of two sclerotised arms connected by a thin internal membrane, the valva is elongate, slim and distally rounded, and the manica lacks pseudocornuti. Furthermore, the wing shape of these species, and other members of the genus Miresa such as M. bilineata Hering, 1928, is very similar. All of these species (except for M. amator) also possess median or post-median fore wing bands. However, it is important to note that Miresa has an Asian type species (M. albipuncta (Herrich-Schäffer, [1854])) described from 'Ind. Bor'., and we are aware that the genus is presently considered pantropical although its monophyly has not been confirmed. In addition, Holloway (1986) stated that the distinction between Parasa Moore, [1860] and Miresa is minimal, so the taxonomic position of the African Miresa and its affinities to other genera requires an in-depth revision.

Taxonomic note
Delorhachis schultzei has been excluded from Delorhachis and synonymised with Hilipoda gravidipes as DNA barcoding has shown the conspecifity of D. schultzei (described from a male holotype) and H. gravidipes (based on a female holotype). This has confirmed that the two species represent the sexually dimorphic male and female of the same species. In both external morphology and genitalia, this species is clearly different to any Delorhachis species, and dissection of the holotype shows very simplified genitalia reminiscent of those observed in the Parasa s.l. generic complex (Solovyev 2014). Hilipoda Karsch, 1896 was described as a monotypic genus for its type species H. gravidipes Karsch, 1896, although the taxon shows striking similarities to species of Parasa, Latoia Guérin-Méneville, [1844], and Stroter Karsch, 1899 in terms of the typical green and dark brown wing colouration of these genera. A full revision of Afrotropical 'green' Limacodidae applying integrative methods is needed to elucidate the taxonomy of these genera.

Genetic information
This species belongs to the BIN URI: BOLD:AEK9086 (n = 2). The synonymy of the names is well supported here, and was only possible through DNA barcoding with so many other Afrotropical green Limacodidae.

Discussion
The present paper provides a comprehensive revision of Delorhachis, describing 11 new species and one new subspecies, and stabilising the nomenclature of other associated taxa. Delorhachis is a widespread genus containing several easily distinguishable species groups. The monophyly of the genus is now well confirmed by certain morphological traits (a medio-ventral fore wing fascia, dark venation in the distal half of the fore wing, and the existence of pseudocornuti on the manica in the male genitalia), and is corroborated by genetic analyses.
This research has identified that Delorhachis occurs throughout a large part of tropical sub-Saharan Africa except for the semi-arid, steppe, and grassland regions south of the Tropic of Capricorn. Most species are associated with drier, deciduous forest-woodland or savannah regions with distinct wet and dry seasons. A number of taxa (including D. meyi, D. kilosa, D. syntomoctena, and D. wetzelae) were recorded from montane forests, and D. chlorodaedala and D. zambica exist at medium-high altitudes of the forested Bié and Zambian plateaus. Several taxa are found in the more humid tropical regions, such as D. viridiplaga, D. ochsei, D. bakossi and D. nimbaensis from the Upper and Lower Guinean rainforests, whilst only D. charopa and D. tommasoi are closely associated with the central dense, swampy, lowland rainforests of the Congo Basin. The widespread D. nigrivenosa occurs throughout much of central and western Africa, although not occurring in the central portion of the Congolian rainforest. More data is needed on less-studied areas of eastern (such as the montane areas of Ethiopia and much of the miombo woodlands of Tanzania) and southern (especially South Africa, Zimbabwe and Mozambique) Africa, which would likely yield more records and provide further information on the habitat preferences of Delorhachis.
The surprisingly large number of species discovered in the genus can be explained in some cases (such as in D. kilosa and D. zambica, or D. viridiplaga and D. ochsei) by biogeographical barriers, but in other taxa (like D. parvinota and D. pallidifascia) the drivers of speciation are much less obvious due to their sympatric distribution. Results may also indicate that the rates of speciation across the Delorhachis species groups are different. For instance, D. pallidifascia, having the northernmost distribution along the Sudanian savannah transition, is not affected by any biogeographical barriers in West Africa, whilst the Volta River clearly separates D. viridiplaga from D. ochsei. Another example is D. chlorodaedala and the D. kilosa and D. zambica species pair, whereby the former extends its range across the western branch of the Rift Valley whilst the latter taxa are clearly separated by this barrier. In particular, the D. syntomoctena species group shows a very high divergence in the genitalia but not so much in external morphology (especially in the case of D. syntomoctena, D. manuelae and D. bakossi). This may suggest that they fill similar ecological niches throughout the lowland Congolian rainforest, and hence there has not been a strong adaptive pressure for them to diverge in external morphology. Peculiarly, D. nimbaensis appears restricted to the Nimba Mountains of Liberia yet shares striking similarities in male genitalia (and is closest in external morphology) to D. smithi, which exists in western Central Africa. Obtaining DNA barcode data of the remaining taxa in this group would provide better insight into the phylogenetic affinities of these species. Further study is needed on the rates and drivers of speciation associated with various biogeographical features throughout the African continent.
Many species within Delorhachis, especially those possessing a green fore wing fascia, look superficially very similar, which may explain the previous lack of a revision, although on closer inspection slight differences in the shape, size, and colour of the fore wing fascia can be seen, as well as in the thorax and tegula patches. In some examples, though, such as in the D. viridiplaga species group, no external morphological differences could be determined yet clear distinctions within the genitalia, distribution, and DNA were found, emphasising the importance of an integrative taxonomic approach to such groups. In addition, the discovery of some species (such as D. nigrivenosa) belonging to multiple BINs on BOLD reiterates the need to consider more than one taxonomic method in species descriptions. This paper has combined extensive material from numerous European collections, providing vast coverage of the Afrotropics which has resulted in a comprehensive overview of a characteristic member of the African Limacodidae.
Komina Amevoin for their support and Lieutenant Mawunya Komi Gbemou, conservateur du P.N. de Fazao Malfakassa, for his competence. In Zambia, Rhoda Kachali (Department of National Parks and Wildlife -ZAWA, Lusaka), Claire Mateke and Martha Imakando (Livingstone Museum, Livingstone) are thanked for the diverse administrative and technical assistance provided during fieldwork, as well as for issuing the research and export permits.
Type specimen images are used with permission and are copyright of the MfN, RBINS, and the Trustees of the NHMUK, and are made available under the Creative Commons Licence 4.0 (https:// creativecommons.org/licenses/by/4.0/).

Disclosure statement
No potential conflict of interest was reported by the authors.