Synaptorhinus FAUST, 1889

Yunakov, N. N. & Klass K. D., 2012, Contribution to the taxonomy and nomenclature of Entiminae from the Palaearctic region and South Africa (Coleoptera: Curculionidae), Beiträge Zur Entomologie = Contributions to Entomology 62 (2), pp. 427-445 : 434-436

Synaptorhinus FAUST, 1889 (new placement)

[type species: Synaptorhinus simplex Faust, 1889 , by monotypy]

This poorly-known monotypic genus was erected for S. simplex Faust, 1889 from Turkey. The original description in Faust (1889) is fairly incomplete, and we thus provide a redescription that includes the morphological details required for comparison with resembling Entiminae genera.

Redescription:

Measurements. Body length 4 mm, width 2.2 mm. V estiture and coloration. Head and body densely covered with round, gold-cupreous scales with slightly pronounced pearl shine. Frontoepistome covered with scattered scales ( Figs 14, 15 ). Antennal scape sparsely covered with slender recumbent and suberect scales; funicle without recumbent scales. Intervals between elytral striae weakly convex, covered with spatulate suberect scales. Light scales form an indistinct pattern of small blurs on the elytra.

Head ( Figs 16-18 , 23 )

Compound eyes small, strongly and irregularly convex, their maximum width situated posteriad of their midlength. Epifrons distinctly narrowed apically, flat. Epistome and frons fused into a frontoepistome; this is coarsely punctate. Epistome with a pair of setae. Frons with weakly developed setal row. Frontoepistome demarcated from epifrons by scattered scales; U-shaped sharp carina not developed. Anterior margin of clypeus bare, without comb of microscopic setae. Ventral side of head ( Fig. 24 ): Prementum broad, rounded, entirely covering buccal cavity, with one pair of setae. Labial palps entirely hidden. Postgenae strongly protruding. Hypostomolabial sutures completely separated and reduced to small pits. Antennae: Robust. Scape evenly but weakly S-shaped and widened apically, 1 st funicular segment 1.5x as long as 2 nd; rest of segments weakly rounded, slightly oblong to as long as wide; club ovate, compact, with fused segments, distinctly bordered from funicle.

Thorax:

Pronotum transverse (PL/PW=0.85), strongly rounded at the sides, widest in posterior half; at posterior margin 1.34x as wide as at anterior margin; its disk weakly and evenly convex longitudinally and transversely ( Fig. 21 ). Legs: Femora obtuse, moderately swollen in middle part. Hind tibiae with simple corbels ( Fig. 26 ). Fore tibiae widened externally ( Fig. 19 ). Fore and middle tibiae slightly mucronate. Hind tibiae with mucro vestigial ( Fig. 28 ). Tibial spurs absent.

Abdomen:

Anal ventrite sharply triangular, its apical edge narrowly rounded, sternite 8 with plate triangular and densely setose ( Fig. 25 ). Tergite 6 sharply sinuate at the apex ( Fig. 30 ).

Genital structures ( Figs 29, 31-33 )

Ovipositor flattened; coxite divided in two sclerites; well developed stick-shaped styli. In spermatheca, ramus and collum very small. Spiculum ventrale with lamella rounded and heavily sclerotized, its anterior margin densely setose; apodeme thick with small caput developed.

Diagnosis and implications on systematic position:

Synaptorhinus was commonly attributed to (or associated with members of) Brachyderini ( Dalla Torre et al. 1936) or Sciaphilini ( Alonso-Zarazaga & Lyal 1999) but either placement may be inadequate as it lacks the typical autapomorphies most of Sciaphilini genera (epistome demarcated from frons by a sharp V-shaped ridge, frontoepistome convex or demarcated from epifrons by U- or V-shaped ridge; except of Euidosomus Reitter, 1904 ) and Brachyderini (anterior margin of clypeus with a comb of microscopic setae).

Synaptorhinus also resembles the Cneorhinini genera Attactagenus Tournier, 1876 , Philopedon Schoenherr, 1826 , and particularly Sericopholus Desbrochers, 1893 in general appearance and the triangular shape of the anal ventrite. However, Synaptorhinus lacks the significant autapomor-autapomorphies of Cneorhinini , which are the presence of an additional setal comb on the hind tibiae (the corbel) and a transversal sulcus separating the epifrons from the remaining head capsule.

On the other hand, Synaptorhinus has strongly protruding postgenae, which likely is an autapomorphy of the Polydrusus subgenus Eudipnus in Polydrusini . Synaptorhinus is particularly similar to P. (E.) lucianae Francia, 1985 in the shape of the head and eyes. On this basis we tentatively place Synaptorhinus Fst. in the tribe Polydrusini , near Eudipnus . It differs from all Eudipnus species by the lack of a frontal fovea and complex of reductions due to the aptery sindrome: reduction of scutellum and humeral processes of elytra.

Type material:

Turkey: Lectotype, female, here designated ( MTD), with labels: gold board; ‘ Asia minor, Pipitz’; ‘Lectotypus Synaptorhinus simplex Faust, Yunakov des., 2009’. Paralectotype, female ( MTD) with the same labels as in lectotype; ‘Paralectotypus Synaptorhinus simplex Faust, Yunakov des., 2009’.

Figures

Figs 14-22: Synaptorhinus simplex Faust, 1889, syntype, female.14: dorsal view; 15: lateral view; 16: head, dorsal view; 17: head outline, dorsal view; 18: head and prothorax outline, lateral view; 19: right protibia, anterior view; 20: scaling of body, schematic; 21: body outline, dorsal view; 22: idem, ventral view, with scaling indicated on left metacoxa.

Figs 23-33: Synaptorhinus simplex Faust, 1889, syntype, female. 23: epistomal area of rostrum, dorsal view; 24: rostrum, ventral view showing buccal cavity; 25: visible abdominal sternites (ventrites), ventral view showing intersternal membranes; 26: right hind tibia apical surface, view from distally, ventral (= internal) side to the right, showing ridge; 27: internal apical angle of right fore tibia, internal view from distally; 28: idem, right middle tibia; 29: spermatheca; 30: abdominal tergite VI, dorsal view; 31: sternite VIII (spiculum ventrale); 32: ovipositor with bursa copulatrix and spermatheca, left-lateral view; 33: left coxite and stylus of ovipositor, magnified. Abbreviations: bc – bursa copulatrix,co – collum, cp– corpus, cr – cornu, cx – coxite, dc– ductus spermaticus, est – epistomal setae, frst – frontal setae, hls – hypostomolabial suture, im – intersternal membrane, md – mandible, muc – mucro, pm – prementum, ptp – posterior tentorial pit, ra – ramus, sc – mandibular scar, sg – subgena, sty –stylus.