Taxonomic revision of the Calotheca parvula species group from southern Africa, with descriptions of three new species (Coleoptera, Chrysomelidae)

Calotheca Heyden, 1887 is a flea beetle genus that occurs predominantly in sub-Saharan Africa, comprising 29 species. The examination of new material is revealing a significantly higher species richness and high intraspecific variability. A group of five species, occurring in the southernmost portion of the distribution range for the genus, is here attributed to the C. parvula species group: C. parvula (Weise, 1908), C. pallida (Bryant, 1945), C. danielssoni sp. nov., C. oberprieleri sp. nov., and C. prinslooi sp. nov. Species in the C. parvula group have strong similarities in body shape and sculpture on the integument, spermathecal shape, and for most species the morphology of the median lobe of the aedeagus. A key to species of the Calotheca parvula group is provided along with photographs of the habitus, main diagnostic characters, median lobe of the aedeagus and spermatheca. In addition to the geographic distribution, the available information on the habitat, host plants, and phenology are provided for the five species analysed.


Introduction
The Alticini are a tribe of leaf beetles (Coleoptera, Chrysomelidae), included in the subfamily Galerucinae, along with the closely related Galerucini (Bouchard et al. 2011). They are the largest and most diverse tribe of leaf beetles, comprising over 540 genera and about 8000 extant species (Nadein 2012;Nadein and Bezděk 2014) and occur all over the world. Alticini are commonly defined as "flea beetles" because they have a metafemoral extensor tendon that enables them to jump (Furth and Suzuki 1998;Ge et al. 2011;Nadein and Betz 2016). Adult and larval stages feed mainly on the stems, leaves or roots, but rarely on the flowers of almost all the higher plant families in different environments, and generally have high levels of specialization (Jolivet and Verma 2002;D'Alessandro et al. 2018b). The Afrotropical flea beetle fauna includes about 1600 known species in 103 genera, but a steady rise in the number of genera and species described during the last 10 years from this region, and the amount of unidentified material preserved in public collections and depositories, show that this taxon is still far from being fully known in Africa (Biondi and D'Alessandro 2008, 2010a, b, 2012, 2013a, b, 2015, 2017Döberl 2010;D'Alessandro et al. 2012D'Alessandro et al. , 2014D'Alessandro et al. , 2018aD'Alessandro et al. , 2019D'Alessandro et al. , 2020Biondi 2017;Biondi et al. 2019Biondi et al. , 2020Biondi, unpublished data;D'Alessandro and Biondi 2018). The Afrotropical flea beetle genus Calotheca Heyden, 1887 was recently separated from the genus Blepharida Chevrolat, 1836(Biondi at al. 2017. It is widespread in sub-Saharan Africa, with limited extensions into Israel and the Arabian Peninsula, and occurs in several types of forest and savannah environments (D'Alessandro et al. , b, 2019Biondi et al. 2019). It can be characterised by the sinuate, deeply impressed frontal grooves, which extend from the dorsal ocular margin to the interantennal space, and the punctate lateral striae on the pronotum. These extend from the anterior margin to the disc and generally are L-or C-shaped. Some species also show short lateral longitudinal furrows or small dimples close to the pronotal base.
In the present contribution we reviewed the taxonomic status of Calotheca parvula (Weise, 1908), from the Republic of South Africa and Namibia, C. pallida (Bryant, 1945), from the Republic of South Africa, and three new species here described from the Republic of South Africa, C. danielssoni sp. nov., C. oberprieleri sp. nov., and C. prinslooi sp. nov.

Material and methods
Material examined consists of 91 dried pinned specimens preserved in the institutions listed under the abbreviations. The specimens were examined, and measurements and dissections were executed, under a Leica M205C stereo microscope. Photographs were taken using a Leica DFC500 camera and compiled using Zerene Stacker software version 1.04. Scanning electron micrographs were taken using a Hitachi TM-1000. Terminology follows D' Alessandro et al. (2016) for the median lobe of aedeagus, and Furth and Suzuki (1994) for the spermatheca. Geographical coordinates for the localities were reported in degrees and minutes (WGS84 format); coordinates and geographical information that are included in square brackets were added to the label data by the authors using data from the Google Earth website. The internationally recognised codens of the depositories follow the list on The Insect and Spider Collections of the World Website (Evenhuis 2020). Chorotypes follow Biondi and D'Alessandro (2006).

Abbreviations
Collections and depositories:

BAQ
Italy, University of L'Aquila, Collection of M. Biondi Diagnosis. Calotheca danielssoni sp. nov. can be distinguished from the other species in the group by the elytral punctures, which are larger and more deeply impressed than those of the pronotal striae (Fig. 1A, D) (elytral punctures as large as, or smaller than, those of the pronotal striae in the other species). Males are similar to C. parvula regarding their small size and the generally darker colour, but are easily distinguishable by the basal pro-and mesotarsomere which are distinctly enlarged (only moderately enlarged in C. parvula) (Figs 1A,4A), and the very different shape of the median lobe of the aedeagus (Figs 1B, C, 4C); females are clearly larger than in C. parvula. Based on the aedeagus, C. danielssoni sp. nov. shows major similarities with C. pallida,C. oberprieleri sp. nov. and C. prinslooi sp. nov. (Figs 1B,C,2C,3C,5C), this is due to: the narrow medial sulcus in the apical third; the apex bearing small ventrolateral bulges (more prominent laterally in some specimens); the paired ventral carinae delimiting a wide ventral sulcus (present in C. pallida and C. prinslooi sp. nov.); and the dorsal ligula formed by two basal and two apical distal lobes. The aedeagus of C. danielssoni sp. nov. is, however, easily distinguishable by the apical part, which is distinctly wider than the remaining length, and the dorsal ligula, with shorter and clearly truncate basal lobes and more elongate distal lobes (Fig. 1B, C).
Etymology. The specific epithet is a noun in the genitive case after Roy Danielsson (Sweden, Lund), one of its collectors. Diagnosis. Calotheca oberprieleri sp. nov. is very similar in shape, size, sculpture and colour to C. pallida and C. prinslooi sp. nov., from which it can be generally distinguished by: surface of median lobe of aedeagus flat ventrally (carinae delimiting a deep sulcus are evident in C. pallida and C. prinslooi sp. nov.) (Figs 2C, 3C, 5C); median lobe sinuate, narrowing in the apical third, wider basally than apically (sinuate and narrowing medially, and as wide basally as apically in C. pallida; and greatest width medially, wider basally than apically and tapering towards the apex in C. prinslooi sp. nov.) (Figs 2C, 3C, 5C); spermatheca only known for one specimen, subreniform and thickset basally (broadly subcylindrical and more slender in C. pallida and C. prinslooi sp. nov.) (Figs 2D, 3D, 5D); pronotal margins which are more rounded laterally (less rounded or more distinctly curved at apical third respectively in C. pallida and C. prinslooi sp. nov.) (Figs 2B, 3B, 5B).
Etymology. The specific epithet is a noun in the genitive case after Rolf G. Oberprieler (Australia, Canberra), one of its collectors.
Ecological notes. Habitat and host plants unknown. Collected between 280-900 m a.s.l. Adults active in November. (Bryant, 1945 Taxonomic remarks. Head, antennae and legs pale brown; tarsi and basal antennomeres even paler brown; pronotum yellow, with punctate lateral striae and basal furrows slightly darkened; elytra yellow, with darkened punctures and, in some specimens, small, sparse irregular pale brown patches on disc (Fig. 3A). Pronotal lateral striae C-shaped, with large deeply impressed punctures; basal furrows of pronotum deeply impressed; pronotal punctation very fine (Fig. 3B). Basal pro-and mesotarsomeres in male distinctly enlarged, subtriangular (Fig. 3A). Median lobe of aedeagus (Fig. 3C) distinctly sinuate laterally in ventral view; as wide basally as distally; apex subtriangular, widely obtuse and rounded laterally with small ventrolateral bulges; ventral surface with two carinae delimiting a wide sulcus, and a narrow distal sulcus in the apical third; ventrolateral surface wrinkled; dorsal ligula short, formed by two subtruncate basal lobes and two shorter subtriangular apical lobes; in lateral view, median lobe distinctly bent down, and sinuate apically. Spermatheca (Fig. 3D) with basal part subcylindrical, relatively slender, distinctly curved; distal part abruptly bent, curved to the apex, with a very short appendix; distal part clearly shorter than half the length of the basal part; ductus basally inserted, elongate, uncoiled but with wide loops.
Chorotype Diagnosis. Calotheca prinslooi sp. nov. is very similar in shape, size, sculpture and colour to C. oberprieleri sp. nov. and C. pallida. Males are easily distinguishable by: the first pro-and mesotarsomeres which are distinctly enlarged and rounded (less enlarged and/or subtriangular in C. oberprieleri sp. nov. and C. pallida) (Figs 2A, 3A, 5A); the aedeagus in ventral view, distinctly wider medially, wider basally than apically, and tapering slightly towards the bluntly rounded apex (sinuate, narrow in the apical third, wider basally than apically in C. oberprieleri sp. nov.; sinuate, narrowing medially, as wide basally as apically in C. pallida), and ventral surface with two basally divergent carinae (ventral surface flat in C. oberprieleri sp. nov.; ventral carinae subparallel in C. pallida) (Figs 2C, 3C, 5C). Females can be distinguished from C. oberprieleri sp. nov. and C. pallida mainly by the shape of the spermatheca, which is quite variable, but never reniform basally as in C. oberprieleri sp. nov., nor with apical part abruptly bent and curved to the apex as in C. pallida (Figs 2D, 3D, 5D).
Etymology. The specific epithet is a noun in the genitive case after Godfried L. Prinsloo (Republic of South Africa, Pretoria), one of its collectors.

Discussion
Calotheca danielssoni sp. nov., C. oberprieleri sp. nov., C. pallida, C. parvula, and C. prinslooi sp. nov. are attributed to the same species group because they share the following characteristics (Figs 1-5): body elongate-elliptical, small to medium sized (4.05 ≤ LB ≤ 6.20 mm); integument from yellow to pale brown, generally with darker reddish-brown to dark brown patches on the pronotum and/or elytra; pronotal lateral striae C-shaped on disc, comprised of large deeply impressed punctures; basal furrows of pronotum deeply impressed; pronotal surface relatively smooth, or at most with shallow lateral depressions and small punctures; elytral punctures large, deeply impressed, and individually darkened -striae not darkened; and simple tarsal claws. Species also share a similar spermathecal morphology (Figs 1E, 2D, 3D, 4D, 5D): basal part elongate and broadly sub-cylindrical; distal part distinctly bent, narrower, and shorter than half of the basal part, with a very small appendix; ductus apically inserted, thickset, moderately to distinctly elongate, generally with some loops and/or a single coil. The median lobe of the aedeagus (Figs 1B, C, 2C, 3C, 4C, 5C) reveals primary affinities among C. danielssoni sp. nov., C. oberprieleri sp. nov., C. pallida and C. prinslooi sp. nov., due to: a narrow ventral medial sulcus in apical third; apex bearing small ventrolateral bulges (apex more prominent laterally in specimens of C. danielssoni sp. nov.); dorsal ligula formed by two basal and two distal lobes; paired ventral carinae delimiting a wide ventral sulcus (present in C. danielssoni sp. nov., C. pallida and C. prinslooi sp. nov.). The group occurs in the southernmost part of the distribution range for the genus, precisely, the Republic of South Africa and Namibia (Fig. 6), which host respectively 22 and 6 Calotheca species based on the present contribution and the previously published data . It is associated with the plant genus Searsia (Anacardiaceae) in fynbos, karoo, and grassland vegetation. Data on host plants thus confirm the association of the genus with the plant family Anacardiaceae.
Key to species of the Calotheca parvula group 1 Elytral punctures larger and more deeply impressed than those of the pronotal striae (Fig. 1A, D). Median lobe of aedeagus with apical part distinctly wider than the remaining length; dorsal ligula with clearly truncate basal lobes, about as long as, or slightly longer than, distal lobes (Fig. 1B, C)  Basal pro-and mesotarsomeres in male moderately enlarged (Fig. 4A). Median lobe of aedeagus (Fig. 4C) narrowing gradually apically to terminate in an acute median tooth; distal lobes of dorsal ligula thinner and more lateral. Body size smaller (LB generally < 5.00 mm in males, and < 5.25 mm in females). Integuments generally darker; pronotum with more evident v-shaped wrinkle near the base, and more evident punctation lining basal margin; a larger elytral patch always present on the suture at the end of the scutellar row of punctures (Fig. 4A)  Surface of median lobe of aedeagus flat ventrally (Fig. 2C). Spermatheca subreniform and thickset basally (Fig. 2D). Pronotal margins more rounded laterally (Fig. 2B)  First pro-and mesotarsomeres in male distinctly enlarged and rounded (Fig. 5A). Median lobe of aedeagus in ventral view, distinctly wider medially, wider basally than apically, and tapering slightly towards the apex (Fig. 5C). Spermatheca never with apical part abruptly bent and curved up to the apex (Fig. 5D) First pro-and mesotarsomeres in male distinctly enlarged and subtriangular (Fig. 3A). Median lobe of aedeagus in ventral view, narrowing medially, as wide basally as apically. Spermatheca with apical part abruptly bent and curved up to the apex (Fig. 3D) (Bryant, 1945) Conclusion C. danielssoni sp. nov., C. oberprieleri sp. nov., C. pallida, C. parvula, and C. prinslooi sp. nov. are here attributed to the C. parvula species group based on their external morphology and characters of the median lobe of the aedeagus and spermatheca. Species can easily be identified by the shape of the median lobe of the aedeagus. Spermathecal characters are generally not reliable for identification, because intraspecific variability can encompass interspecific variability. However, the combination of some unique external characters and spermathecal features may be useful to also distinguish females (see Key to species). The genus Calotheca currently includes 32 species. However, new material under examination reveals the occurrence of several undetermined species, along with a high degree of variability within the already known species (Biondi, unpublished data). The study of that material and the revision of the described species will provide a more in-depth insight into the contribution that Calotheca gives to the African biodiversity.