Synapsis horaki Zidek and Pokorny, 2010

Zidek, Jiri & Pokorny, Svatopluk, 2010, Review of Synapsis Bates (Scarabaeidae: Scarabaeinae: Coprini), with description of a new species, Insecta Mundi 2010 (142), pp. 1-21 : 8-9

Synapsis horaki Zidek and Pokorny , sp. nov.

Fig. 12-15

Type. Holotype male from N. Vietnam, Vinh Phu District , Tam Dao, alt. 900 m, leg. Jan Horak 6- 10.V.1990. Deposited at NMPC. No other material.

Etymology. Named for the collector.

Description. Length from anterior margin of clypeus to posterior margin of elytra 24 mm. Black, moderately glossy, glabrous except for setose margins of clypeus, genae, pronotum and legs.

Head. Anterior margin of clypeus medially excised into a V-shape, upturned and carinate, lateral of excision weakly undulate. Frons medially swollen, without a tubercle. Suture between clypeus and gena well defined. Genae nearly right-angled, with lateral terminations rounded and hind margins slanted toward eyes. Sculpture granulo-punctate on clypeus and frons, granulose on genae; granules flattened.

Prothorax. Pronotum transverse, about 2.5x wider than long, widest at anterior quarter of length, moderately arched, finely punctate throughout, punctures denser toward sides and base; anterior and lateral margins carinate, base complete only medially, against first three intervals of each elytron; anterolateral angles form short, blunt saliences on lateral margins followed by angularities. Hypomeral cavity shallow and granulose, nearly devoid of setae; pleuron posterior of cavity very sparsely punctate, punctures large and shallow.

Pterothorax. Elytra moderately arched, with carinate base and ten weakly impressed moniliform striae whose punctures do not extend into intervals. Intervals flat, microrugose (x15). Second interval of each elytron near base with a small but well defined swelling. Mesepisternum granulose. Metasternum punctate on disc and granulose laterally, in posterior half with a longitudinal trough that deepens toward metacoxae.

Abdomen. Ventrites microrugose, sparsely punctate (x15). Pygidium with margins complete throughout, densely, transversely punctate, punctures asperate. Aedeagus with parameres symmetrical, slightly shorter than phallobase; parameres dorsally narrow, without medial lobes, dorso-laterally thick but not inflated, with blunt tips.

Legs. Ventral faces of all femora densely punctate, most coarsely on profemur. Metafemur with indistinct midventral row of slightly coarser, confluent, distally setose punctures and posterior tooth reduced to minor angulation at proximal one-third of length. Protibia tridentate, protarsus slightly longer than protibial spur and about as long as terminal protibial tooth. Meso- and metatibial spurs slender, straight. Medial (posterior) mesotibial spur and metatibial spur half as long as respective tarsi, lateral (anterior) mesotibial spur about half as long as medial spur.

Comparison. Synapsis horaki belongs in the birmanica group and is closely allied to S. yama Gillet ( Fig. 8-11 ), which is larger (27-29 mm) but otherwise inseparable from S. horaki by dorsal habitus. The near absence of hypomeral setae in the holotype of S. horaki is taxonomically meaningless (see Comment under S. punctata ), the characters that distinguish between S. horaki and S. yama are the pronotal base, femora and aedeagi. In S. yama the pronotal base is carinate throughout its length, femoral puncturing is virtually absent (except for a short midventral row of large, setose punctures at distal end of the metafemur), the metafemoral posterior tooth is much stronger and situated at midlength, and the parameres have dorsomedial lobes and are markedly dorso-ventrally inflated. Both species are known from north Vietnam, but the specimens of S. yama that we have seen were collected at altitudes around 300 m, whereas S. horaki comes from 900 m.

Another similar species appears to be S. masumotoi Ochi from Taiwan, which has the pronotal base carinate throughout (like S. yama ), the elytral intervals “almost flat”, microgranulose and finely wrinkled (like both S. yama and S. horaki ), the ventral face of the metafemur punctate (like S. horaki ), the posterior metafemoral tooth situated at midlength (like S. yama ), and parameres seemingly intermediate (drawn and therefore hard to compare). We have not been able to see this species, our comparison is based solely on the original description and a photo provided by M. Kon. However, the character mosaic and insular occurrence seem to indicate that S. masumotoi is a valid species.

Figures

Figure 8-15. The birmanica group. 8-11) S. yama Gillet. 8) Male, 26 mm. 9) Aedeagus, dorsal. 10) Aedeagus, left lateral. 11) Left metafemur, ventral. 12-15) S. horaki sp. nov. 12) HT male, 24 mm. 13) Aedeagus, dorsal. 14) Aedeagus, left lateral. 15) Left metafemur, ventral.