A new species of Diaphorocera from Morocco with unclear relationships and a key to the species (Coleoptera, Meloidae, Cerocomini)

Abstract Diaphorocera neglecta sp. n. from Morocco is described. Photos of the new species are provided and male features are figured. The new species has intermediate characters between the groups of D. hemprichi and D. promelaena as defined in the literature. These groups are discussed and a new key to the species is presented.


Introduction
Diaphorocera Heyden, 1863 is a Saharo-Sindian genus, most diverse in the western Sahara Desert and belonging to the tribe Cerocomini, family Meloidae. The phylogenetic relationships within the tribe were defined on the basis of both morphological and molecular evidence by Turco and Bologna (2008), who pointed out the affinities of Diaphorocera with the eastern African genus Somalarthrocera Turco & Bologna, 2008. The genus was revised by Turco and Bologna (2007) who also summarised the distribution and bionomics of each species.
Diaphorocera is characterised by a metallic green-blue body, but with legs, antennae and mouthparts being yellow-orange in most species. Male antennae are extremely modified, as in other genera of the tribe and composed of eleven antennomeres. Turco and Bologna (2007) considered Diaphorocera and the genus Anisarthrocera as primitive elements within the tribe, both being strictly adapted to eremic habitats.
The aims of this paper are to describe a new species from eastern Morocco, D. neglecta sp. n., the ninth species in the genus, showing intermediate characters between the groups of D. hemprichi Heyden, 1863 andD. promelaena Fairmaire, 1876 , as defined in the literature and to design a new key to the species.

Materials and methods
Available specimens were examined using stereomicroscopes and measurements were taken with an ocular grid. The total length of the examined specimens is measured from the anterior apex of mandibles to the apex of elytra. Proportions of antennomeres were taken on holotype male measurements. Male genitalia were dissected and glued onto a paper label.
Photographs were takenby an Olympus OM-D E-M5 camera equipped with a macro lens Olympus M.Zuiko Digital ED 60 mm f/2.8 Macro.The type specimens are labelled with a printed red rectangular label: "HOLOTYPUS or PARATYPUS respectively, Diaphorocera neglecta sp. n., M. A. Bologna & L. Černý des. 2016". All specimens are glued onto paper labels.
Examined specimens are preserved in the following collections: Diagnosis. A Diaphorocera species characterized by male elongate last antennomere and simple fore tibiae, with head, pronotum and ventral parts dark shiny metallic blue.
Description. Male (Fig. 1). Body. Head, pronotum, thorax, abdomen distinctly dark blue metallic, elytra green-blue metallic; coxae, trochanters, femurs, tibiae, and tarsi orange, but metatarsi darker and mesotarsi slightly darkened. Body and leg setation clear yellowish and in some parts almost white. Length: 9.8-9.9 mm. Head with punctures sparse, wide, and deep, surface among punctures smooth and shiny. Maximum width at level of eyes and temples, temple parallel, as long as the eye. Frontal callus smooth, neither keeled nor anteriorly protruding, in lateral view only few convex. Antennae as in Fig. 3; antennomeres I-XI orange, VIII-X with a single, linear and short black stripe on the apical portion of each antennomere, middle in position on VIII-IX, more basal on X; the extreme pointed apex of IV and VI black; XI very elongate, 2.8 times long as wide; X ca. 2/3 as long as XI. Mouthparts orange except the apical third of mandibles black; maxillary palpomere as in Fig. 4, last palpomere dark, as labial palpomeres; labrum ca. 3 times as long as clypeus and with a middle furrow dorsally. Pronotum narrow and parallel on the basal half, distinctly longer than wide, anteriorly restricted and with two lateral grooves on sides. Surface with punctures similar to those on the head, sparse but deep, surface among punctures smooth, shiny, and a longitudinal non-punctured area in the middle extending from the base to the anterior third of the length. Elytra with surface densely and coarsely punctuated, punctures merging together. Foretibiae simple and not modified; metatibial outer spur widened and spoon-like. Male genitalia as in Figs 5-6; aedeagus inclined on fore third, with two short and pointed hooks, hooks of the endophallic duct bent differently; lobes of parameres diverting and obtuse apically.
Female (Fig. 2). Body colouration similar to male. Antennae unmodified, length of antennomere XI equal to that of previous three together, antennomeres III-X transverse, wider than long (see Fig. 2). Lack lateral grooves of pronotum. Protibiae distinctly pointed and acuminate on external fore angle. Length: 12.5 mm.
Etymology. Following the recent revision of the genera (Turco and Bologna 2007) and due to the rarity of this Diaphorocera species, we named it neglecta (= neglected, ignored) according to the Latin adjective (feminine in the nominative case). Systematic remarks. Turco and Bologna (2007) established three groups of species within the genus based on a cladistic analysis: (i) the obscuritarsis group (carinicollis, johnsoni, obscuritarsis) with the last male antennomere subquadrate and unmodified simple foretibiae; (ii) the promelaena group (promelaena) characterised by the last antennomere elongate, male foretibia modified only distally and by black body and pronotum; (iii) the hemprichi group (chrysoprasis, hemprichi, sicardi, peyerimhoffi) with the last antennomere elongate and foretibiae modified. The new species differs from all described species due to the combination of characters mixed between those of the promelaena and hemprichi groups. D. neglecta has the last antennomere elongate as in both groups but the fore tibiae are simple, differently than in these groups; both these characters represent a plesiotypic condition. It is distinct from D. promelaena because its head, pronotum and ventral parts are dark metallic blue and not sub-opaque black. Moreover its pronotum is slender, longer than wide rather than as long as wide, and the black ornamentations on antennomeres VIII-X being lacking in D. promelaena.
Diaphorocera neglecta is more similar to the species of the hemprichi group because of the body colouration, the shape of pronotum and antennae, and probably represent a basal element without foretibial modification. It differs from all species of this heterogeneous group because of the shape of almost all antennomeres and of male genitalia; in particular the ventral shape of gonoforceps are slightly similar to that of D. hemprichi.The ornamentation on antennomeres is present only in D. sicardi, but differs greatly from that of this species which moreover is clearly distinguished by its foretibial shape.
Tentatively the new species is inserted in the group of hemprichi, as basal in position, although its relationship needs to be tested by molecular analysis and the possible relationships with the group of D. promelaena explored. A second attempt to collect further specimens of this species in the same locality (on 22 April 2017) failed, probably due to much drier conditions. Distribution. The new species was collected only in the type locality (Fig. 7), but since the local desert environment is widely and homogeneously spread, its occurrence in other eremic habitats of the eastern Morocco is possible.
In E Morocco and SW Algeria, in localities close to Erfoud, six species of Diaphorocera are distributed (Turco and Bologna 2007); D. promelaena is syntopic with the new species. No differences in the ecological niche among these six species have been identified in the literature, all of them being synchronic and polyphagous.