Prosymnus testaceiventris Pic, 1932

Opitz, Weston, 2016, Classification, Natural History, and Evolution of the Korynetinae (Coleoptera: Cleridae). Part III. The African GeneraEctospinulaOpitz, New Genus, andProsymnusLaporte, The Coleopterists Bulletin 70 (3), pp. 429-446 : 429-446

Prosymnus testaceiventris Pic, 1932 ( Figs. 27 , 35 , 36 , 39 )

Prosymnus testaceiventris Pic 1932: 8 . Lectotype. Here designated. Sex unknown. Elizabetville (Lubumashi), XI-1911, Miss. Agric. ( Democratic Republic of the Congo). (MRAC). Corporaal 1950: 300. Pic did not indicate in his description whether his nominal species is based on one or more specimens. Therefore, I invoke Recommendation 73F of the ICZN (1999) and designate a lectotype for this nominal species.

Prosymnus maculipennis Pic 1934a: 66 . Lectotype. Here designated. Gender unknown. Baudouinville, I-1933, L. Burgeon (MRAC). New Synonymy. The characteristics upon which this nominal species is based fall into the range of variation of P. testaceiventris .

Diagnosis. Within Prosymnus , the members of this species are distinguished by the arenose condition of the interstitial spaces of the elytral disc.

Redescription. Size: Length 8.0 mm; width 3.5 mm. Form: As in Fig. 27 . Color: Cranium, prothorax, elytra, castaneous, legs, antennae, pterothorax, and abdomen testaceous. Head: Antennal capitulum lax, antennomeres 9 and 10 triangular, antennomere 11 oval; eyes much narrower than frons (EW/FW 30/70). Thorax: Pronotum transverse (PW/PL 140/125), spine on pronotal posterior angle well-developed; elytral punctation subseriate, punctation extending to elytral apex, elytral interstitial spaces arenose. Abdomen: Setal patches on 4 th sternite; male pygidium scutiform; aedeagus as in Fig. 35 .

Natural History. Specimens were collected throughout the year, some at light and some at 1,200 m elevation.

Distribution. In addition to the types, I examined 16 specimens from: DEMOCRATIC REPUBLIC OF THE CONGO: Elisabethville (à la lumière), I-III-52/ 30-IX-1953, Ch. Seydel; idem, - II-1940, H. J. Brédo; idem, Katanga, 15-III-

1939, light trap, H. J. Bredo; idem, XII-1938, H. J. Bredo; Locandu , - III-1939, Capt. Marée; Baudounville , I-1933, L. Burgeon; Lualaba: Ruwe, (plège Lumineux) 1/II-1960, Dr. V. Allard. ANGOLA: 23 km W Vila Folgares, 1200 m, 8-XII-1966, E. S. Ross & K. Lorenzen ( Fig. 39 ). Specimens are deposited in CASC, ISNB, MNHN, MRAC , and WOPC.

EVOLUTIONARY CONSIDERATIONS

This treatise deals with the genera Ectospinula and Prosymnus , which together form a monophyletic group within Korynetinae (sensu Opitz 2010). Ectospinula is monotypic, whereas Prosymnus involves eight species. Despite the paucity of morphological diversity among Prosymnus species , two major lines of evolution are apparent. Both lines concern the macrosculpture of the elytral disc. In the astrictus-brevipenis lineage, the elytral disc is laden with swellings and large, randomly distributed punctation, whereas in the livens-mulleri lineage, the elytral disc is level and the punctations are relatively small and subseriate.

PHYLOGENETIC INTERPRETATIONS

The phylogeny in Fig. 36 depicts my current understanding of the phylogenetic relationships of the taxa included in this work. The WINCLADA and NONA analyses produced one tree with the following indices: L = 17; Ci = 100; and Ri = 100. The monophyletic status of the Ectospinula / Prosymnus lineage is based on the presence of crenulations on the lateral pronotal margins and the presence, in all but two members, of a welldeveloped spine on the posterior angle of the pronotum; the exception is found in the Prosymnus arsus / mulleri branch, which I posit represents a secondary loss. The Prosymnus lineage is considered monophyletic in view of the presence in all members of: 1) crenulations on the upper margin of epipleural fold; 2) a deep body form; and 3) abdominal setal patches.

Information from label data suggests that the beetles under study are most commonly found among woodland angiosperms. Taking this into account, along with the known distribution of the Ectospinula / Prosymnus species , it is postulated that the ancestor of these sister genera (progenitor B) evolved in southern Africa, south of the Sahara, prior to the Miocene when woodland/forest habitats had not yet given way to the more openwoodland grasslands ( Cerling et al. 1997). This ancestor evolved a spine on the posterior angle of the pronotum. Subsequently, progenitor B produced two evolutionary lines. One line led to Ectospinula , the other to ancestor C, which is the progenitor of Prosymnus species characterized by a deep body form, crenulate upper margin of the epipleural fold, and sterna setal patches on the abdomen. Ancestral species C diverged to evolve progenitor D, characterized by elevated elytral interstitial spaces, coarsely cribrate elytral disc, and elytral 2° setae variously tufted. Ancestor C also evolved the sister lineage based by ancestral species F. In the latter, the elytral punctation became subseriate and smaller. Progenitor D diverged to evolve P. astrictus and the basal stock, ancestor E, which produced the geographically widespread P. rudis and P. brevipenis , whose collection records bring to mind the “arid corridor” distribution pattern proposed by van Zinderen Bakker (1969). Ancestral species F diverged to produce progenitor G, which led to P. livens and P. adustus . Its sister lineage produced ancestral species H, which bifurcated to produce P. testaceiventris and progenitor I. The latter, in which the elytral disc emits a metallic sheen, eventually evolved P. arsus and the South African P. mulleri .

Figures

Fig. 27. Prosymnus testaceiventris, habitus.

Figs. 28–35. Prosymnus species, male terminalia. 28) P. adustus; 29) P. arsus; 30) P. astrictus; 31) P. brevipenis;

Fig. 36. Phylogenetic tree computed from the character matrix (Table 1) for Ectospinula graduata and Prosymnus species.

Figs. 37–40. Geographic distribution of Ectospinula graduata and Prosymnus species.