Integrative taxonomic revision of the African taxa of the Racotis Moore, 1887 generic complex (Lepidoptera, Geometridae, Ennominae, Boarmiini)
Author
László, Gyula M.
0000-0001-9862-8290
gyulalaszlo@anhrt.org.uk
Author
Hausmann, Axel
0000-0002-0358-9928
hausmann.a@snsb.de
Author
Karisch, Timm
0000-0001-9862-8290
gyulalaszlo@anhrt.org.uk
text
Zootaxa
2023
2023-06-26
5308
1
1
109
http://dx.doi.org/10.11646/zootaxa.5308.1.1
journal article
10.11646/zootaxa.5308.1.1
1175-5326
8080929
CCA5F817-6B5F-4BE5-BEFB-EDE98C07A0EE
Zebracotis
subgen. n.
Type
species:
Racotis zebrina
Warren, 1899
Genetic analyses
(Text fig. 3). The subgenus was recovered as a well-supported sister clade of the subgenus
Afroracotis
with high support in both analyses (BS: 55; PP: 97). The DNA barcode-based infrageneric classification of the subgenus, however, is rather inconsistent often conflicting with the clearly distinguished morphotaxa. Based on certain constant morphological characters discussed below, the subgenus contains ten taxa (nine species and one subspecies), while only seven BINs in the complex were assigned in BOLD. The topologies of the BI and ML trees are nearly identical and both are rather incongruent with the morphology-based taxon delineations, where a single morphological taxon is often split into two separate genetic clusters without any diagnostic characters. Such an example is
A. milesi
sp. n.
, which was recovered as paraphyletic: in a cluster of exclusively Gabonese specimens BIN-sharing with
A. zebrina
,
A. chaineyi
sp. n.
and
A. lydiae orientalis
ssp. n.
and in a distinct cluster with its own BIN URI comprising
A. milesi
samples from
Zambia
,
Cameroon
and
Gabon
. Another example of such incongruency between genetics and morphology is
A. lydiae
sp. n.
which is morphologically subdivided into a West (nominotypical taxon) and East African subspecies (
A. lydiae orientalis
ssp. n.
), however, the West African subspecies is recovered as a genetically largely separate cluster with its own BIN URI, whereas the East African subspecies is BIN-sharing with the predominantly West African
A. zebrina
, the mainly central African
A. milesi
sp. n.
and the more widespread
A. smithi
sp. n.
. The only taxa showing genetic features being congruent with morphology are
A. madagascariensis
(
Chainey & Karisch, 2017
)
which is recovered as a sister clade to all other
Zebracotis
taxa in both analyses (BS: 67%, PP: 100%),
A. ochsei
sp. n.
,
A. takanoi
sp. n.
and
A. helicalis
sp. n.
, although the last one clusters as a sister species to
A. lydiae lydiae
despite their largely dissimilar genital morphology. It is difficult to reliably establish the reason of such an extent of conflicts between genetics and morphology in the
Zebracotis
subgenus. Seemingly, DNA barcodes have limited taxonomic relevance in this group, possibly due to repeated genetic introgression. Alternatively, the members of the subgenus may be evolutionary very young taxa “in statu nascendi”, where the speciation has been manifested in an early divergence in genital morphology before a clear differentiation in the external morphology and COI DNA sequences could have taken place. It is also worth noting that the single COI-5P gene region used in the genetic analyses is relatively short and an in-depth genetic analysis based on multiple gene regions (including nDNA) would presumably result in a better resolution of the phylogeny. Overall, as the tree topology of the
Zebracotis
subgenus is not entirely congruent with the morphological species concept, the taxa in this subgenus have been delimited based primarily on the remarkable and constant differences observed in the genital morphology.
TEXT
FIGURE 3
.
ML tree of the subgenus
Zebracotis
based on analysis of COI barcodes. Bootstrap values are indicated above, posterior probability values below the branches. Samples which have not been confirmed by dissection are labelled as ‘indet’.
Diagnosis.
The species of the subgenus are characterized by the broad, triangular forewing, the dark greyish-green colouration of densely speckled scales on the upperside, the well-defined, ovoidal discal spots, and the variably contrasting row of round black patches representing the subterminal line. As the wing pattern varies largely both infra- and interspecifically, the facies of most of the species do not provide reliable distinctive features for species-level identification. In the males of all members of the subgenus, the third abdominal sternite bears a small tuft of fine setae, a character which is also found in
A. squalida
and in the monotypic subgenus
Sokokeracotis
subgen. n.
within
Afroracotis
, however, it is also present in the sister genus
Chorocotis
gen. n.
. The diagnostic male genitalia characters of the subgenus are as follows:
Zebracotis
has a clasping apparatus similar to that of
Herbuloracotis
, but it has a longer uncus, a medially inverse V-shaped gnathos without a shield-like medial plate, a ventro-medially more concave valva, and a considerably more elongate juxta, medially tapered into a narrow distal projection. The vesica of the
Zebracotis
species bears highly distinctive characters allowing reliable species-level identification. It is characterized by the medium long and moderately inflated main vesica chamber, in most species with a well-developed diverticulum with an apical cornutus of specific shape and a group of cornuti erected distally at the base of the vesica ejaculatorius. The shared characters of the
Zebracotis
species in the female genitalia are the sclerotised, broad cup-shaped antrum, the absence of the membranous ductus bursae replaced by the variably elongate heavily sclerotised cervix bursae which is fully merged into the corpus bursae forming a sclerotised posterior section. The lack of true ductus bursae clearly separates the
Zebracotis
subgenus from all other lineages of
Afroracotis
.
Description
External features of body and wings
(
Figs 81–119
,
175–204
). Forewing length
17–24 mm
. Male antenna bipectinate-fasciculate, rami moderately long, distal section filiform, varying from 1/2 to 2/5 of length of antenna. Female antenna filiform. Head moderately large, proboscis well-developed, labial palp short, length 1.2–1.5 times the diameter of eye, porrect, first and second segment dilated, third segment rather short and thin. Compound eyes moderately large. Frons, vertex, collar (patagium), tegula, thorax and abdomen colouration as of wing upperside. Legs rather long, colouration as of wing underside, index of spurs 0-2-4. Forewing broad, triangular, costa straight, apical section slightly arched, termen straight to slightly arched, ventral margin almost straight. Ground colour varying inter- and intraspecifically from dark rusty-brown to greenish-grey usually with mossy tinge, densely speckled with groups of brownish-grey scales, basal and medial area often lighter than terminal one, postmedial area with series of large dark blotches. Transverse lines diffuse, interrupted. Basal, subbasal and antemedial line poorly detectable, interrupted, often partly deleted, more or less straight, or gently arched. Medial line often interrupted, shadow-like, slightly S-curved, postmedial line diffuse, slightly wavy, subterminal line represented by a row of patches of variable size, terminal line narrow, often interrupted, consisting of black dashes or arches between veins. Fringe (cilia) short, concolourous with forewing. Discal spot well-developed, round or ovoid with lighter inner area. Hindwing apex rounded, termen evenly arcuate, slightly scalloped, anal margin straight. Ground colour as of forewing, densely speckled, transverse lines diffuse, shadow-like, basal line evenly arched, wavy or sharply angled medially, medial line undulate, postmedial line interrupted, terminal line sometimes interrupted, consisting of black arches between veins. Discal spot as of forewing. Fringe (cilia) short, concolourous with hindwing. Wing underside with pale brownish-grey basal and medial area speckled densely with greyish-brown scales, terminal area with broad, dark transverse band. Traces of transverse lines present, diffuse, shadow-like, discal spot and postmedial patches well-defined.
Male genitalia
(
Figs 254–283
). Uncus simple, moderately long, distally tapered, apex narrowly rounded. Tegumen short and broad, gnathos well-developed, apically rounded. Valva short, broad at base, distally tapered, costal margin slightly concave, sclerotised, sparsely setose, without apical projection.Ventral margin of valva convex basally and subapically, smoothly concave medially; sacculus short and broad, weakly sclerotised, without process. Juxta weakly sclerotised, distally tapered, elongate shield-like without arms. Vinculum moderately long and broad, V-shaped, apically rounded.Aedeagus rather thick, short to medium long, straight or slightly curved, without carina. Vesica thick, relatively long, in some species with protractile diverticulum armed with a robust apical cornutus, and, in all but one species (
A. zebrina
) with a small group of cornuti situated near the base of vesica ejaculatorius.
Female genitalia
(
Figs 320–338
). Ovipositor medium long, papilla analis narrow triangular, apically rounded, sparsely setose, apophysis posterioris moderately long. Eighth tergite medium long, trapezoidal, distal margin slightly arcuate, proximal margin undulate with a shallow medial depression, anterior apophysis shorter than posterior apophysis. Ostium bursae broad, membranous, antrum moderately sclerotised, short, funnel-, cup-, goblet-shaped or inverse trapezoidal. Distal section of ductus bursae membranous, very short and narrow, may be fully reduced; proximal part tubular or funnel-shaped, varying in length interspecifically, directly continued in sclerotised distal part of corpus bursae. Cervix bursae well-developed, heavily sclerotised, fully integrated into corpus bursae forming a sclerotised, longitudinally striate distal section of bursa copulatrix. Membranous anterior part of corpus bursae varied in size interspecifically, may be almost fully reduced; corpus bursae with a strongly sclerotised, smooth-surfaced disc-like or quadrangular plate supposedly serving as receptive area of cornutus vesicae during copulation; signum absent.
Species content
Afroracotis (Zebracotis) zebrina
(
Warren, 1899
)
comb. nov.
Afroracotis (Zebracotis)
chaineyi
sp. n.
Afroracotis (Zebracotis)
lydiae
sp. n.
Afroracotis (Zebracotis)
lydiae orientalis
ssp. n.
Afroracotis (Zebracotis) madagascariensis
(
Chainey & Karisch, 2017
)
comb. nov.
Afroracotis (Zebracotis)
smithi
sp. n.
Afroracotis (Zebracotis)
milesi
sp. n.
Afroracotis (Zebracotis)
ochsei
sp. n.
Afroracotis (Zebracotis)
helicalis
sp. n.
Afroracotis (Zebracotis)
takanoi
sp. n.